scientificamerican--2020-10-30--Living near a White Dwarf

Living near a White Dwarf

Recently , the first planet to orbit a white dwarf—the latter named WD 1856+534—was discovered through its transit in front of the tiny star once every 1.4 days .
Remarkably , this giant planet , WD 1856b , is seven times bigger than the stellar remnant it transits .
Most likely , there are rocky , Earth-size planets at similar distances from other white dwarfs—in which case they would possess a surface temperature similar to that of Earth .
This hits us close to home .
In about a billion years , the sun will brighten up enough to boil @ @ @ @ @ @ @ runaway greenhouse effect .
In order to survive , our civilization will have to migrate outwards in the solar system .
Seven billion years later , the core of the sun will shrink to its remnant , a white dwarf , carrying about half of the solar mass with the rest lost .
A white dwarf is a hot , dense , metallic crystal ball , roughly the size of the Earth—1.4 Earth radii in the case of WD 1856+534—that is slowly cooling off because it no longer has a central nuclear engine @ @ @ @ @ @ @ in the Milky Way galaxy because many sunlike stars have already gone through the process of dying .
This is a result of a fortuitous coincidence between the life span of sunlike stars and the current age of the universe .
After a few billion years , a white dwarf cools to a surface temperature similar to that of the present-day sun .
In particular , WD 1856+534 was estimated to have an age of 6 billion years and a surface temperature of 4,700 kelvins , somewhat lower than the current solar value @ @ @ @ @ @ @ planet is 50 times closer to WD 1856+534 than the Earth ’ s distance from the sun .
Since this white dwarf is 76 times smaller in size than the sun , an observer located just inside the orbit of the newly detected planet , at about 1 percent of the Earth-sun separation , would witness an illumination similar to that on Earth , with WD 1856+534 occupying roughly the same angle as the sun does in our sky .
In such a “ habitable zone ” around any white dwarf , the @ @ @ @ @ @ @ suggested in a 2011 paper , liquid water could exist on the surface of a rocky planet , enabling the chemistry of life as we know it .
Owing to the short orbital time , residents of a habitable world around WD 1856+534 would be busy celebrating their birthday once every 33 hours—the length of a year on that planet .
Given that the luminous surface area of a white dwarf is 10,000 times smaller than that of the sun , absorption features from a planet ’ s atmosphere during a transit of @ @ @ @ @ @ @ detectable than for sunlike stars .
During a full transit , which would last a few minutes , an Earth-size planet would occult the entire white dwarf .
Given the proximity of the planet to the star , the transit repetition rate is hundreds of times larger compared to the habitable zone of a sunlike star .
As argued in my 2013 paper with Dan Maoz of Tel-Aviv University , these circumstances offer the best opportunity for detecting biosignatures in the atmospheres of exoplanets , in the spirit of the phosphine detection in @ @ @ @ @ @ @ , Venus .
Our calculations were refined in a recent paper by Lisa Kaltenegger at Cornell and collaborators .
If the planet hosts a technological civilization , one could also search for signs of industrial pollution in its atmosphere , as demonstrated in my follow-up study with Henry Lin and Gonzalo Gonzalez-Abad at Harvard in 2014 .
A close-in habitable planet will be tidally locked—showing the same face to the white dwarf , with permanent dayside and nightside .
As it turns out , the habitability distance is dangerously close to the region @ @ @ @ @ @ @ the gravitational tidal force from the white dwarf .
Since the habitable zone is not very far from this tidal disruption distance , tides could raise a substantial bulge in any ocean or atmosphere on the planet ’ s surface .
What are the implications for our own long-term future ?
As the sun evolves into a white dwarf , our descendants could aim to populate the habitable zone near its remnant .
For astronomy , a tidally locked planet would offer the benefit of a permanent nightside where telescopes can be placed @ @ @ @ @ @ @ For the economy , the white dwarf surface would offer the efficiency of nuclear reactors without creating radioactive waste .
By damping trash onto the surface of the white dwarf , one could harvest its gravitational binding energy from the emitted electromagnetic radiation at nearly the yield of nuclear fuel .
Given this perspective , there might already be analogs of our civilization that recognized the benefits of living around white dwarfs .
We could find them by searching for the spectral signatures of the trash they damp on the white dwarf surface @ @ @ @ @ @ @ ( CFC ) pollution of their planet ’ s atmosphere from their air conditioners .
Among all industrial civilizations , it would be easiest to detect the environmental impact of mildly intelligent ones—those who are not friendly to their habitat .
The only problem is that these civilizations might destroy themselves relatively quickly and consequently be less abundant .

Recently, the first planet to orbit a white dwarf—the latter named WD 1856+534—was discovered through its transit in front of the tiny star once every 1.4 days. Remarkably, this giant planet, WD 1856b, is seven times bigger than the stellar remnant it transits. Most likely, there are rocky, Earth-size planets at similar distances from other white dwarfs—in which case they would possess a surface temperature similar to that of Earth. This hits us close to home.
In about a billion years, the sun will brighten up enough to boil away the oceans on Earth through a runaway greenhouse effect. In order to survive, our civilization will have to migrate outwards in the solar system. Seven billion years later, the core of the sun will shrink to its remnant, a white dwarf, carrying about half of the solar mass with the rest lost.
A white dwarf is a hot, dense, metallic crystal ball, roughly the size of the Earth—1.4 Earth radii in the case of WD 1856+534—that is slowly cooling off because it no longer has a central nuclear engine. There are 10 billion white dwarfs in the Milky Way galaxy because many sunlike stars have already gone through the process of dying. This is a result of a fortuitous coincidence between the life span of sunlike stars and the current age of the universe.
After a few billion years, a white dwarf cools to a surface temperature similar to that of the present-day sun. In particular, WD 1856+534 was estimated to have an age of 6 billion years and a surface temperature of 4,700 kelvins, somewhat lower than the current solar value of 5,800 kelvins. The newly discovered planet is 50 times closer to WD 1856+534 than the Earth’s distance from the sun.
Since this white dwarf is 76 times smaller in size than the sun, an observer located just inside the orbit of the newly detected planet, at about 1 percent of the Earth-sun separation, would witness an illumination similar to that on Earth, with WD 1856+534 occupying roughly the same angle as the sun does in our sky. In such a “habitable zone” around any white dwarf, the University of Washington’s Eric Agol suggested in a 2011 paper, liquid water could exist on the surface of a rocky planet, enabling the chemistry of life as we know it. Owing to the short orbital time, residents of a habitable world around WD 1856+534 would be busy celebrating their birthday once every 33 hours—the length of a year on that planet.
Given that the luminous surface area of a white dwarf is 10,000 times smaller than that of the sun, absorption features from a planet’s atmosphere during a transit of a white dwarf are much more easily detectable than for sunlike stars. During a full transit, which would last a few minutes, an Earth-size planet would occult the entire white dwarf. Given the proximity of the planet to the star, the transit repetition rate is hundreds of times larger compared to the habitable zone of a sunlike star. As argued in my 2013 paper with Dan Maoz of Tel-Aviv University, these circumstances offer the best opportunity for detecting biosignatures in the atmospheres of exoplanets, in the spirit of the phosphine detection in the cloud deck of our neighboring planet, Venus. Our calculations were refined in a recent paper by Lisa Kaltenegger at Cornell and collaborators. If the planet hosts a technological civilization, one could also search for signs of industrial pollution in its atmosphere, as demonstrated in my follow-up study with Henry Lin and Gonzalo Gonzalez-Abad at Harvard in 2014.
A close-in habitable planet will be tidally locked—showing the same face to the white dwarf, with permanent dayside and nightside. As it turns out, the habitability distance is dangerously close to the region where the planet would be destroyed by the gravitational tidal force from the white dwarf. Since the habitable zone is not very far from this tidal disruption distance, tides could raise a substantial bulge in any ocean or atmosphere on the planet’s surface.
What are the implications for our own long-term future? As the sun evolves into a white dwarf, our descendants could aim to populate the habitable zone near its remnant. For astronomy, a tidally locked planet would offer the benefit of a permanent nightside where telescopes can be placed to observe their dark sky nonstop. For the economy, the white dwarf surface would offer the efficiency of nuclear reactors without creating radioactive waste. By damping trash onto the surface of the white dwarf, one could harvest its gravitational binding energy from the emitted electromagnetic radiation at nearly the yield of nuclear fuel.
Given this perspective, there might already be analogs of our civilization that recognized the benefits of living around white dwarfs. We could find them by searching for the spectral signatures of the trash they damp on the white dwarf surface, or by searching for the chlorofluorocarbon (CFC) pollution of their planet’s atmosphere from their air conditioners. Among all industrial civilizations, it would be easiest to detect the environmental impact of mildly intelligent ones—those who are not friendly to their habitat. The only problem is that these civilizations might destroy themselves relatively quickly and consequently be less abundant.


scientificamerican--2020-10-30--Election Science Stakes: Energy

Election Science Stakes: Energy

Steve Mirsky : For this energy installment of our pre-election podcast series I spoke once again to Scientific American editors Mark Fischetti and Andrea Thompson .
SM : What 's at stake in this election in terms of energy in this country ?
Mark Fischetti : So I think there 's two things , Steve .
One is oil .
On October 27 , the U.S. Department of Interior approved a huge oil development project in western Alaska by ConocoPhillips .
So that 's clearly where the current administration is happy to go .
The other issue is electricity .
@ @ @ @ @ @ @ fossil fuels or more so on renewable energy ?
And I think there 's a lot of interesting state races that have some bearing in that too .
SM : That 's a good point , because we 're not just talking about the presidential election .
We 're talking about the election in general .
Andrea Thompson : It 's an interesting area , because the President and Congress can shape things to a large degree .
But then there are also market forces that come into play that can counteract things @ @ @ @ @ @ @ despite during the first four years of the Trump administration , this push towards fossil fuels and to boost them , we still see renewables really surge in their use , and they ’ ve become comparatively cheaper , especially compared to coal .
And that 's really happened in spite of any efforts the Trump administration has made , because of technological developments , because companies are moving in that direction regardless of what the administration wants to do .
So that will kind of complicate or mitigate what could happen in @ @ @ @ @ @ @ What can the government do to nudge that market selection pressure one way or the other .
AT : So besides allowing for fossil fuel development on public lands , which the federal government controls , and there 's hundreds of millions of acres of public lands in the U.S , they also can affect it through things like tariffs and subsidies .
So one thing President Trump has indicated he wants to do is to increase tariffs on solar panels .
And so that could actually impact the solar power market .
@ @ @ @ @ @ @ reasons , not necessarily energy-specific reasons , that he 's done that .
But that , you know , that adds to the cost and makes it a little bit harder for them to compete .
MF : By the way , I would add that , you know , there are still subsidies to this day for oil and natural gas .
They 're hardly new technologies .
It really does change the equation because there are plenty of studies that show purely on cost and energy delivery that renewables—wind and solar—are @ @ @ @ @ @ @ but they do n't stay cheaper if fossil fuels have subsidies .
SM : So what 's the story on fracking right now ?
AT : Generally , following the Trump administration general pro-fossil-fuel stance they are for allowing fracking on on federal lands and new leases Whereas the Biden position has been that they would discontinue new leases , although leases that are already established would be allowed .
And then those do n't impact any fracking on private land .
So it ’ s a little bit of a mixed bag @

Full Transcript
Steve Mirsky: For this energy installment of our pre-election podcast series I spoke once again to Scientific American editors Mark Fischetti and Andrea Thompson.
SM: What's at stake in this election in terms of energy in this country?
Mark Fischetti: So I think there's two things, Steve. One is oil. On October 27, the U.S. Department of Interior approved a huge oil development project in western Alaska by ConocoPhillips. So that's clearly where the current administration is happy to go. The other issue is electricity. Will it continue to be built on fossil fuels or more so on renewable energy? And I think there's a lot of interesting state races that have some bearing in that too.
SM: That's a good point, because we're not just talking about the presidential election. We're talking about the election in general.
Andrea Thompson: It's an interesting area, because the President and Congress can shape things to a large degree. But then there are also market forces that come into play that can counteract things he's trying to do. So despite during the first four years of the Trump administration, this push towards fossil fuels and to boost them, we still see renewables really surge in their use, and they’ve become comparatively cheaper, especially compared to coal. And that's really happened in spite of any efforts the Trump administration has made, because of technological developments, because companies are moving in that direction regardless of what the administration wants to do. So that will kind of complicate or mitigate what could happen in the next four years.
SM: What can the government do to nudge that market selection pressure one way or the other.
AT: So besides allowing for fossil fuel development on public lands, which the federal government controls, and there's hundreds of millions of acres of public lands in the U.S, they also can affect it through things like tariffs and subsidies. So one thing President Trump has indicated he wants to do is to increase tariffs on solar panels. And so that could actually impact the solar power market. And that's partly been for trade reasons, not necessarily energy-specific reasons, that he's done that. But that, you know, that adds to the cost and makes it a little bit harder for them to compete.
MF: By the way, I would add that, you know, there are still subsidies to this day for oil and natural gas. They're hardly new technologies. It really does change the equation because there are plenty of studies that show purely on cost and energy delivery that renewables—wind and solar—are actually cheaper than many fossil fuels, but they don't stay cheaper if fossil fuels have subsidies.
SM: So what's the story on fracking right now?
AT: Generally, following the Trump administration general pro-fossil-fuel stance they are for allowing fracking on on federal lands and new leases Whereas the Biden position has been that they would discontinue new leases, although leases that are already established would be allowed. And then those don't impact any fracking on private land. So it’s a little bit of a mixed bag.
—Steve Mirsky
(The above text is a transcript of this podcast)


scientificamerican--2020-10-30--Climate Helped Turn These 5 Places into Ghost Towns

Climate change is creating American ghost towns with a regularity not seen since the 19th century , when boomtowns sprouted and died as quickly as their resources could be devoured .
Today , disasters are hollowing out more small communities and erasing important cultural , historical and religous sites , leaving only painful memories and sometimes nothing .
Just this year , multiple hurricanes struck the Louisiana coast , including Zeta earlier this week .
It remains a mystery whether Cameron and Creole , just 12 miles apart along the southwest Louisiana coast , will survive after back-to-back hits from @ @ @ @ @ @ @ has more opened graves than open businesses , and most of its residents have evacuated to other places .
“ The storm surge just pushed the caskets up out of the ground , ” said Stephanie Rodrigue of Creole , La.
, where Delta made landfall earlier this month as a Category 1 storm .
“ There ’ s been a huge effort over the past two months to find and relocate all of the missing caskets and missing monuments.
” Whether Cameron finds its missing residents is an open question .
Some @ @ @ @ @ @ @ t .
Experts say the town can ’ t sustain future hurricane blows .
It began dying after Hurricanes Rita and Ike in 2005 and 2008 , respectively .
The town ’ s population plummeted by nearly 80 % , leaving just 400 souls behind .
“ The folks that are still there—the parish officials—they may not want to talk about it , but they see the big picture , ” said Edward Richards , director of the Climate Change Law and Policy Project at Louisiana State University .
“ They have a @ @ @ @ @ @ @ folks who are left behind , but they know there ’ s no future there.
” Here are five more towns , old and new , that died ( or are dying ) from climate-related disasters : Even the U.S. War Department couldn ’ t save Burrwood .
The vanished town , built on a prong of the Mississippi River ’ s bird foot-shaped delta , succumbed to subsidence , wave erosion and wetlands destruction .
Army Corps of Engineers dredges operated out of Burrwood at the turn of the 20th century to @ @ @ @ @ @ @ New Orleans .
It became a garrison town in 1941 when the Roosevelt administration rushed to establish “ Section Burrwood Naval Base ” to thwart German submarines and U-boats from encroaching on the Mississippi River .
“ The base ’ s heavy duty docks were capable of supporting not only pilot boats and civilian tugs and dredges , but also patrol craft , sub chasers , minesweepers , PT boats , and vessels as large as destroyers , ” according to a historical summary of Burrwood compiled by Louisiana State University .
Burrwood @ @ @ @ @ @ @ in 1917 and 1965 , when Hurricane Betsy swept across the delta on its way to New Orleans .
Betsy is widely considered the worst New Orleans hurricane before Hurricane Katrina in 2005 .
Today , the only sign of life in the area once known as Burrwood is a ship pilots station rising from the marsh .
As LSU ’ s history puts it , “ Burrwood no longer exists.
” For years , the spookiest place on Maryland ’ s Eastern Shore was not a ghost town , but a decrepit @ @ @ @ @ @ @ Chesapeake Bay .
The two-story house , built in 1888 , was all that remained of Holland Island , one of a string of ever-shrinking towns where “ watermen ” —and women—have struggled to stay afloat as sea-level rise and wave action chew away their beloved marsh islands .
Scientists forecast that climate change will take all of the bay ’ s island communities by the end of the century .
Holland was simply the first ; its last home collapsed in 2010 , days before Halloween .
At its peak , Holland @ @ @ @ @ @ @ post office , a school , a church , a dance hall and a traveling baseball team , according to the 2005 book “ The Disappearing Islands of the Chesapeake ” by the former Johns Hopkins University marine scientist and historian William Cronin .
Early islanders began leaving in the mid-1910s .
A century of storms and rising tides hastened its end .
Its sole champion , a retired Methodist minister and former waterman Stephen White , spent years trying to save the island by ringing it with rocks , planks and sandbags @ @ @ @ @ @ @ he sold the white house to a private foundation .
Later that year , it collapsed under its own weight .
White blamed elected officials for failing to address the bay ’ s environmental ills .
“ That ’ s a bitter pill for me to swallow , ” he told The Baltimore Sun in 2010 from his home on Deal Island , another sinking bay hamlet ( Climatewire , June 15 , 2017 ) .
“ It ’ s like I lost a loved one , but at the same time , @ @ @ @ @ @ @ Valmeyer drowned 27 years ago during the Mississippi River ’ s Great Flood of 1993 .
Then it came back , refusing to let the powerful , deadly river determine its fate .
Today , Valmeyer sits on a high bluff overlooking the Big Muddy .
The views are better ; the town is growing ; and residents can watch their old community turn into farmland , recreation fields and natural floodplain .
“ I wouldn ’ t call what we did a [ climate ] adaptation project so much as a survival @ @ @ @ @ @ @ Valmeyer ’ s former mayor who oversaw the original town ’ s destruction , demolition , retreat and reconstruction .
The vestiges of “ Original Valmeyer ” still haunt the floodplain .
Residents can drive its skeletal streets in search of artifacts and fading memories .
About 10 homes remain on what used to be called “ the high side of town.
” Some owners rejected a federal buyout , placing their faith in the Army Corps of Engineers ’ rebuilt levees .
Those defenses were tested last year when the Mississippi River @ @ @ @ @ @ @ 93 .
“ It was a nail-biter for a while , ” said Knobloch .
“ We don ’ t have to worry as much because we don ’ t have as much at stake anymore .
But we still have friends and some folks have family who live down there .
You still get concerned for them.
” In the Sierra Nevada north of Redding , a preserved 19th-century mining town called Shasta City didn ’ t survive a modern-day blaze .
It ’ s now a “ dead town.
” The @ @ @ @ @ @ @ gold rush museum by the California Department of Parks and Recreation as Shasta State Historic Park , burned in the Carr Fire in 2018 .
Its only remnants are the brick facades and iron window shutters of main street buildings erected more than 150 years ago .
A similar fate met the historic mining district of Helena a year earlier , when a wildfire consumed more than 22,000 acres of remote Trinity County .
Tiny Helena , “ one of the oldest surviving pioneer mining settlements in California , ” had stood for @ @ @ @ @ @ @ complex is on the National Register of Historic Places .
“ Those are two towns that are getting more ghostly , ” said Yana Valochovic , an extension forest adviser at the University of California .
Fire is nothing new to Northern California , but climate change is making those fires more severe , experts say .
Shasta and Helena never had a chance .
Fire crews didn ’ t have the luxury in 2017 and 2018 of saving historic ghost towns .
There almost certainly will be more “ dead towns ” @ @ @ @ @ @ @ , Valochovic added .
“ It ’ s hard to imagine that there are towns that are just drying up and disappearing because of a climate-related issue , ” she said .
“ If you have a place that ’ s based on a single industry , that ’ s how you get these new ghost towns.
” Turns out California ’ s tourism-dependent “ ghost towns ” are such places .
On the upcoming events webpage of Shasta State Historic Park , the message is clear : “ No events scheduled at @ @ @ @ @ @ @ ) death : Hurricanes , sea-level rise Legend holds that every developer who tried to lay hands on Cumberland Island turned up dead .
Several did , as did some famous guests .
Today , the wild barrier island owned by the National Park Service could soon be destroyed as climate-juiced hurricanes and sea-level rise threaten to wash it away .
Accessible only by ferry , Cumberland ’ s windswept beaches and impenetrable live oak forests hold some of the South Atlantic ’ s most important natural and historic treasures , including a @ @ @ @ @ @ @ and elusive ghost crabs .
Its historic African American church hosted the 1996 wedding of John F. Kennedy Jr. and Carolyn Bessette-Kennedy , both of whom died in a plane crash three years later .
It was also the place of death of former Virginia Gov .
Henry Lee III , father of the Confederate Gen. Robert E. Lee .
Dungeness , a mansion ruin , was built in the 18th century by James Oglethorpe , a founder of the British colony of Georgia .
It later changed hands to Revolutionary War Gen. @ @ @ @ @ @ @ Washington , who died destitute at age 43 .
The original mansion burned in 1866 .
Thomas Carnegie , brother of the industrialist Andrew Carnegie , purchased the island in the late 1880s .
The family rebuilt Dungeness and occupied the house until 1925 .
It burned again in 1959 , allegedly by arson .
Reprinted from Climatewire with permission from E & E News .
E & E provides daily coverage of essential energy and environmental news at www.eenews.net .

Climate change is creating American ghost towns with a regularity not seen since the 19th century, when boomtowns sprouted and died as quickly as their resources could be devoured.
Today, disasters are hollowing out more small communities and erasing important cultural, historical and religous sites, leaving only painful memories and sometimes nothing.
Just this year, multiple hurricanes struck the Louisiana coast, including Zeta earlier this week. It remains a mystery whether Cameron and Creole, just 12 miles apart along the southwest Louisiana coast, will survive after back-to-back hits from Hurricanes Laura and Delta
Today, Cameron has more opened graves than open businesses, and most of its residents have evacuated to other places.
“The storm surge just pushed the caskets up out of the ground,” said Stephanie Rodrigue of Creole, La., where Delta made landfall earlier this month as a Category 1 storm. “There’s been a huge effort over the past two months to find and relocate all of the missing caskets and missing monuments.”
Whether Cameron finds its missing residents is an open question. Some will come back. Some won’t. Experts say the town can’t sustain future hurricane blows. It began dying after Hurricanes Rita and Ike in 2005 and 2008, respectively. The town’s population plummeted by nearly 80%, leaving just 400 souls behind.
“The folks that are still there—the parish officials—they may not want to talk about it, but they see the big picture,” said Edward Richards, director of the Climate Change Law and Policy Project at Louisiana State University. “They have a sense of responsibility to the handful of folks who are left behind, but they know there’s no future there.”
Here are five more towns, old and new, that died (or are dying) from climate-related disasters:
Burrwood, La.
Cause of death: Erosion/subsidence
Even the U.S. War Department couldn’t save Burrwood.
The vanished town, built on a prong of the Mississippi River’s bird foot-shaped delta, succumbed to subsidence, wave erosion and wetlands destruction.
Army Corps of Engineers dredges operated out of Burrwood at the turn of the 20th century to maintain the Southwest Pass navigation channel to New Orleans. It became a garrison town in 1941 when the Roosevelt administration rushed to establish “Section Burrwood Naval Base” to thwart German submarines and U-boats from encroaching on the Mississippi River.
“The base’s heavy duty docks were capable of supporting not only pilot boats and civilian tugs and dredges, but also patrol craft, sub chasers, minesweepers, PT boats, and vessels as large as destroyers,” according to a historical summary of Burrwood compiled by Louisiana State University.
Burrwood also experienced repeated hurricane strikes, notably in 1917 and 1965, when Hurricane Betsy swept across the delta on its way to New Orleans. Betsy is widely considered the worst New Orleans hurricane before Hurricane Katrina in 2005.
Today, the only sign of life in the area once known as Burrwood is a ship pilots station rising from the marsh. As LSU’s history puts it, “Burrwood no longer exists.”
Holland Island, Md.
Cause of death: Erosion/sea-level rise
For years, the spookiest place on Maryland’s Eastern Shore was not a ghost town, but a decrepit white house in the middle of the Chesapeake Bay.
The two-story house, built in 1888, was all that remained of Holland Island, one of a string of ever-shrinking towns where “watermen”—and women—have struggled to stay afloat as sea-level rise and wave action chew away their beloved marsh islands.
Scientists forecast that climate change will take all of the bay’s island communities by the end of the century. Holland was simply the first; its last home collapsed in 2010, days before Halloween.
At its peak, Holland Island supported roughly 70 homes, a post office, a school, a church, a dance hall and a traveling baseball team, according to the 2005 book “The Disappearing Islands of the Chesapeake” by the former Johns Hopkins University marine scientist and historian William Cronin.
Early islanders began leaving in the mid-1910s. A century of storms and rising tides hastened its end.
Its sole champion, a retired Methodist minister and former waterman Stephen White, spent years trying to save the island by ringing it with rocks, planks and sandbags. Nothing worked. In 2010, he sold the white house to a private foundation. Later that year, it collapsed under its own weight.
White blamed elected officials for failing to address the bay’s environmental ills.
“That’s a bitter pill for me to swallow,” he told The Baltimore Sun in 2010 from his home on Deal Island, another sinking bay hamlet (Climatewire, June 15, 2017). “It’s like I lost a loved one, but at the same time, I’m angry about it.”
Valmeyer, Ill.
Cause of death: River flood
Valmeyer drowned 27 years ago during the Mississippi River’s Great Flood of 1993. Then it came back, refusing to let the powerful, deadly river determine its fate.
Today, Valmeyer sits on a high bluff overlooking the Big Muddy. The views are better; the town is growing; and residents can watch their old community turn into farmland, recreation fields and natural floodplain.
“I wouldn’t call what we did a [climate] adaptation project so much as a survival project,” said Dennis Knobloch, Valmeyer’s former mayor who oversaw the original town’s destruction, demolition, retreat and reconstruction.
The vestiges of “Original Valmeyer” still haunt the floodplain. Residents can drive its skeletal streets in search of artifacts and fading memories.
About 10 homes remain on what used to be called “the high side of town.” Some owners rejected a federal buyout, placing their faith in the Army Corps of Engineers’ rebuilt levees. Those defenses were tested last year when the Mississippi River rose to heights not seen since ’93.
“It was a nail-biter for a while,” said Knobloch. “We don’t have to worry as much because we don’t have as much at stake anymore. But we still have friends and some folks have family who live down there. You still get concerned for them.”
Historic Shasta and Helena, Calif.
Cause of death: Wildfire
In the Sierra Nevada north of Redding, a preserved 19th-century mining town called Shasta City didn’t survive a modern-day blaze. It’s now a “dead town.”
The site, maintained since 1937 as a gold rush museum by the California Department of Parks and Recreation as Shasta State Historic Park, burned in the Carr Fire in 2018. Its only remnants are the brick facades and iron window shutters of main street buildings erected more than 150 years ago.
A similar fate met the historic mining district of Helena a year earlier, when a wildfire consumed more than 22,000 acres of remote Trinity County. Tiny Helena, “one of the oldest surviving pioneer mining settlements in California,” had stood for 170 years. Its 430-acre, five-building complex is on the National Register of Historic Places.
“Those are two towns that are getting more ghostly,” said Yana Valochovic, an extension forest adviser at the University of California.
Fire is nothing new to Northern California, but climate change is making those fires more severe, experts say. Shasta and Helena never had a chance. Fire crews didn’t have the luxury in 2017 and 2018 of saving historic ghost towns.
There almost certainly will be more “dead towns” as fires consume more of Northern California, Valochovic added.
“It’s hard to imagine that there are towns that are just drying up and disappearing because of a climate-related issue,” she said. “If you have a place that’s based on a single industry, that’s how you get these new ghost towns.”
Turns out California’s tourism-dependent “ghost towns” are such places. On the upcoming events webpage of Shasta State Historic Park, the message is clear: “No events scheduled at this moment.”
Cumberland Island, Ga.
Cause of (possible) death: Hurricanes, sea-level rise
Legend holds that every developer who tried to lay hands on Cumberland Island turned up dead. Several did, as did some famous guests.
Today, the wild barrier island owned by the National Park Service could soon be destroyed as climate-juiced hurricanes and sea-level rise threaten to wash it away.
Accessible only by ferry, Cumberland’s windswept beaches and impenetrable live oak forests hold some of the South Atlantic’s most important natural and historic treasures, including a maritime wilderness, endangered loggerhead sea turtles and elusive ghost crabs.
Its historic African American church hosted the 1996 wedding of John F. Kennedy Jr. and Carolyn Bessette-Kennedy, both of whom died in a plane crash three years later. It was also the place of death of former Virginia Gov. Henry Lee III, father of the Confederate Gen. Robert E. Lee.
Dungeness, a mansion ruin, was built in the 18th century by James Oglethorpe, a founder of the British colony of Georgia. It later changed hands to Revolutionary War Gen. Nathanael Greene, a confidant of George Washington, who died destitute at age 43. The original mansion burned in 1866.
Thomas Carnegie, brother of the industrialist Andrew Carnegie, purchased the island in the late 1880s. The family rebuilt Dungeness and occupied the house until 1925. It burned again in 1959, allegedly by arson.
Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.


scientificamerican--2020-10-30--Coronavirus News Roundup, October 24-October 30

The items below are highlights from the free newsletter , “ Smart , useful , science stuff about COVID-19.
” To receive newsletter issues daily in your inbox , sign up here : This 10/28/20 story in El País , by Mariano Zafra and Javier Salas , features excellent visuals that illustrate the airborne risk of SARS-CoV-2 infection for a set number of people in indoor settings for several hours under various additive conditions , including : a ) no protective measures , b ) people consistently wear masks , c ) masks are worn , the premises are ventilated @ @ @ @ @ @ @ the setting .
The settings include a living room , a bar or restaurant , and a school classroom .
The illustrations rely on calculations yielded by a tool developed by atmospheric chemist Jose-Luis Jimenez of the University of Colorado Boulder , and colleagues .
A lot of us are facing difficult decisions these days about traveling and gathering for holidays .
“ Staying home is the best way to protect yourself and others ” from SARS-CoV-2 , according to the introduction to a helpful interactive on travel safety published at The Washington @ @ @ @ @ @ @ of five questions on topics such as lodging , mode of travel or travel companions , the interactive returns a summary of the associated virus-transmission risk , travel safety tips , testing advice , and preventive measures you can or should take , such as quarantining , mask-wearing , hand-washing , social distancing , and advance discussions .
Clever headline on this 10/23/20 Kaiser Health News story : “ Travel on Thanksgiving ?
Pass the COVID.
” The piece by Anna Almendrala rounds up lots of helpful advice : 1 ) ideally , @ @ @ @ @ @ @ t widen your social circles for the holiday , the story states ; 2 ) if you travel locally to dine with others , interact only with people in your household , aka self-quarantine , for two weeks before the event to minimize risk ( this is only feasible for people who do not work outside the home and people without children attending school in-person ; your housemates must also self-quarantine for this to be effective ) ; 3 ) California ’ s Department of Public Health issued these “ harm-reduction ” guidelines @ @ @ @ @ @ @ ; 4 ) if you fly , “ get tested before the flight for peace of mind , buy tickets on a plane that is leaving middle seats empty , use highly protective N95 masks and possibly face shields , and blast the individual airplane vents directly onto each family member to disrupt potential virus particles .
And , of course , wash your hands frequently.
” For the Washington Post , Natalie B. Compton stayed at a budget , mid-range , and upscale hotels to assess their SARS-CoV-2 prevention measures ( 10/13/20 @ @ @ @ @ @ @ ’ re as safe at a budget hotel as you are at a mid-range hotel , but there is no safety advantage to staying in an expensive “ luxury ” hotel .
Relevant measures at a Holiday Inn Express included automatic doors to the main entrance , social distancing stickers on the lobby floor , plexiglass panels to separate guests and desk workers , and to-go breakfast bags .
At a Hyatt , Compton found a hand sanitizer dispenser in the lobby , plexiglass dividers at the check-in desk , contact-less check-in , @ @ @ @ @ @ @ gym available by appointment .
If you haven ’ t yet devised or purchased a portable air cleaner for your home , school , or workplace , here ’ s an advice essay on the topic , by freelance writer Laura Daily for The Washington Post ( 10/19/20 ) .
Two well-respected public health researchers who focus on indoor air both recommend placing portable air cleaners with HEPA ( high-efficiency particulate air ) filters in school classrooms , Daily writes .
Know the area of the room where you wish to install a @ @ @ @ @ @ @ ’ s specifications to ensure that it can handle the job .
The piece links to a site created by researchers at the Harvard School of Public Health and University of Colorado , Boulder that can be used to select an appropriate air filter for a room of specific dimensions .
Air cleaners at home are likely worth considering only if you live with someone whose job or school puts them in contact with others , the piece suggests .
Air purifiers do not eliminate the risk of indoor transmission , so continue @ @ @ @ @ @ @ and distance if guests visit , the story describes the experts as advising .
At Wired , Gregory Barber revisits the weak , indirect evidence that touching recently infected surfaces and then our face is a significant way that SARS-CoV-2 spreads ( 10/20/20 ) .
Nearly all cases of transmission now have been linked to “ shared air , ” although transmission from surfaces ( known in infectious disease research as “ fomites ” ) can not be entirely ruled out , he reports .
Early evidence on the persistence of the virus @ @ @ @ @ @ @ fomite freakout ” this spring , according to a Princeton University mathematical biologist who is quoted in the story and coauthored the early surface-persistence research .
Yes , SARS-CoV-2 can persist on some hard surfaces for hours or days , but these data say nothing about one ’ s personal risk for infection , the dose of viral particles transferred , the likelihood of particles entering your airway and infecting you , and other real-life ( not laboratory ) conditions like humidity , temperature , and light levels , the story states .
@ @ @ @ @ @ @ , and people at high-risk for COVID-19 “ may want to take extra precautions , ” Barber writes .
At this point , many people and organizations remain needlessly fixated on obsessively wiping down school , church , library , public transit and household surfaces , the story suggests .
“ Worrying about the small stuff exhausts people from focusing on things that do matter , ” Barber writes .
A 10/14/20 guide to forming a pandemic pod with close friends and/or families to help make the U.S. winter more bearable offers the @ @ @ @ @ @ @ pod only with people who share your level of risk tolerance and exposure control practices ; 2 ) keep the size of your pod as small as five to 10 people ; 3 ) create a pact of rules and standards , possibly in writing , for all pod members ; and 4 ) make a response plan ahead of time in case a pod member tests positive for SARS-CoV-2 .
By Allyson Chiu at The Washington Post .
Check out this thought-provoking examination by Sam Bloch at The Counter of claims that @ @ @ @ @ @ @ to COVID-19 ( 10/15/20 ) .
It ’ s a complicated issue .
Sure , a less healthy diet is linked to obesity , diabetes , heart disease , and high blood pressure , and those risk factors put one at higher risk for severe COVID-19 .
However , that does not explain why the incidence of COVID-19 is higher in the U.S. than it is in other countries with similar obesity rates , suggests a University of North Carolina at Chapel Hill nutrition researcher .
And the risk of dying from COVID-19 @ @ @ @ @ @ @ , irrespective of obesity , points out a Harvard School of Public Health policy researcher .
Assertions that people choose healthy or unhealthy diets are on shaky ground , in part because healthier foods ( fruits , vegetables , lean meats ) cost more than calorie-dense , nutrient-poor foods such as soda pop and corn-derived snacks .
Plus : “ If people were becoming irresponsible , you ’ d expect to see it in areas other than food , ” the director of the World Food Policy Center at Duke University is quoted @ @ @ @ @ @ @ look at other health-related behaviors—like , do people brush and floss , do they wear seatbelts , or do they get preventive medical exams—over time , the rates of those things has improved or stayed the same.
” An inexpensive , over-the-counter drug often used as a treatment against parasitic worms is in high demand in Perú , Bolivia , Guatemala and other parts of Latin America as an unproven preventative for COVID-19 , reports freelance science journalist Emiliano Rodríguez Mega for Nature ( 10/20/20 ) .
Little evidence suggests that the drug @ @ @ @ @ @ @ the story states .
Now , the popularity of the drug makes it difficult for COVID-19 researchers to find potential study subjects who have not already taken it , Rodríguez Mega reports .
The drug has been linked to tremors , convulsions , lethargy , and disorientation , as well as brain damage and comas in people with a certain genetic mutation , Rodríguez Mega writes .
A global health researcher at Cayetano Heredia University in Perú is quoted as saying : “ What we ’ re having is a populist treatment , @ @ @ @ @ @ @ researchers continue to try to recruit patients for small-scale or ongoing studies of the drug ’ s possible effectiveness against COVID-19 , the story states .
Science magazine 's Dance Your PhD competition is on , now with an additional COVID-19 category .
The submission deadline is 1/29/21 ( Science , 10/26/20 ) .

The items below are highlights from the free newsletter, “Smart, useful, science stuff about COVID-19.” To receive newsletter issues daily in your inbox, sign up here:
This 10/28/20 story in El País, by Mariano Zafra and Javier Salas, features excellent visuals that illustrate the airborne risk of SARS-CoV-2 infection for a set number of people in indoor settings for several hours under various additive conditions, including: a) no protective measures, b) people consistently wear masks, c) masks are worn, the premises are ventilated, and people spend fewer hours in the setting. The settings include a living room, a bar or restaurant, and a school classroom. The illustrations rely on calculations yielded by a tool developed by atmospheric chemist Jose-Luis Jimenez of the University of Colorado Boulder, and colleagues.
A lot of us are facing difficult decisions these days about traveling and gathering for holidays. “Staying home is the best way to protect yourself and others” from SARS-CoV-2, according to the introduction to a helpful interactive on travel safety published at The Washington Post (10/5/20). For each of five questions on topics such as lodging, mode of travel or travel companions, the interactive returns a summary of the associated virus-transmission risk, travel safety tips, testing advice, and preventive measures you can or should take, such as quarantining, mask-wearing, hand-washing, social distancing, and advance discussions.
Clever headline on this 10/23/20 Kaiser Health News story: “Travel on Thanksgiving? Pass the COVID.” The piece by Anna Almendrala rounds up lots of helpful advice: 1) ideally, don’t travel and don’t widen your social circles for the holiday, the story states; 2) if you travel locally to dine with others, interact only with people in your household, aka self-quarantine, for two weeks before the event to minimize risk (this is only feasible for people who do not work outside the home and people without children attending school in-person; your housemates must also self-quarantine for this to be effective); 3) California’s Department of Public Health issued these “harm-reduction” guidelines for people who do attend holiday gatherings; 4) if you fly, “get tested before the flight for peace of mind, buy tickets on a plane that is leaving middle seats empty, use highly protective N95 masks and possibly face shields, and blast the individual airplane vents directly onto each family member to disrupt potential virus particles. And, of course, wash your hands frequently.”
For the Washington Post, Natalie B. Compton stayed at a budget, mid-range, and upscale hotels to assess their SARS-CoV-2 prevention measures (10/13/20). The story suggests that you’re as safe at a budget hotel as you are at a mid-range hotel, but there is no safety advantage to staying in an expensive “luxury” hotel. Relevant measures at a Holiday Inn Express included automatic doors to the main entrance, social distancing stickers on the lobby floor, plexiglass panels to separate guests and desk workers, and to-go breakfast bags. At a Hyatt, Compton found a hand sanitizer dispenser in the lobby, plexiglass dividers at the check-in desk, contact-less check-in, extra disinfection of rooms, and a gym available by appointment.
If you haven’t yet devised or purchased a portable air cleaner for your home, school, or workplace, here’s an advice essay on the topic, by freelance writer Laura Daily for The Washington Post (10/19/20). Two well-respected public health researchers who focus on indoor air both recommend placing portable air cleaners with HEPA (high-efficiency particulate air) filters in school classrooms, Daily writes. Know the area of the room where you wish to install a filter, and then check the device’s specifications to ensure that it can handle the job. The piece links to a site created by researchers at the Harvard School of Public Health and University of Colorado, Boulder that can be used to select an appropriate air filter for a room of specific dimensions. Air cleaners at home are likely worth considering only if you live with someone whose job or school puts them in contact with others, the piece suggests. Air purifiers do not eliminate the risk of indoor transmission, so continue to wear a mask, wash hands and distance if guests visit, the story describes the experts as advising.
At Wired, Gregory Barber revisits the weak, indirect evidence that touching recently infected surfaces and then our face is a significant way that SARS-CoV-2 spreads (10/20/20). Nearly all cases of transmission now have been linked to “shared air,” although transmission from surfaces (known in infectious disease research as “fomites”) cannot be entirely ruled out, he reports. Early evidence on the persistence of the virus on surfaces led to “the great fomite freakout” this spring, according to a Princeton University mathematical biologist who is quoted in the story and coauthored the early surface-persistence research. Yes, SARS-CoV-2 can persist on some hard surfaces for hours or days, but these data say nothing about one’s personal risk for infection, the dose of viral particles transferred, the likelihood of particles entering your airway and infecting you, and other real-life (not laboratory) conditions like humidity, temperature, and light levels, the story states. Hospitals should still wipe down high-touch objects, and people at high-risk for COVID-19 “may want to take extra precautions,” Barber writes. At this point, many people and organizations remain needlessly fixated on obsessively wiping down school, church, library, public transit and household surfaces, the story suggests. “Worrying about the small stuff exhausts people from focusing on things that do matter,” Barber writes.
A 10/14/20 guide to forming a pandemic pod with close friends and/or families to help make the U.S. winter more bearable offers the following advice: 1) form a pod only with people who share your level of risk tolerance and exposure control practices; 2) keep the size of your pod as small as five to 10 people; 3) create a pact of rules and standards, possibly in writing, for all pod members; and 4) make a response plan ahead of time in case a pod member tests positive for SARS-CoV-2. By Allyson Chiu at The Washington Post.
Check out this thought-provoking examination by Sam Bloch at The Counter of claims that individuals with unhealthy diets are more vulnerable to COVID-19 (10/15/20). It’s a complicated issue. Sure, a less healthy diet is linked to obesity, diabetes, heart disease, and high blood pressure, and those risk factors put one at higher risk for severe COVID-19. However, that does not explain why the incidence of COVID-19 is higher in the U.S. than it is in other countries with similar obesity rates, suggests a University of North Carolina at Chapel Hill nutrition researcher. And the risk of dying from COVID-19 is higher among black and Latino populations, irrespective of obesity, points out a Harvard School of Public Health policy researcher. Assertions that people choose healthy or unhealthy diets are on shaky ground, in part because healthier foods (fruits, vegetables, lean meats) cost more than calorie-dense, nutrient-poor foods such as soda pop and corn-derived snacks. Plus: “If people were becoming irresponsible, you’d expect to see it in areas other than food,” the director of the World Food Policy Center at Duke University is quoted as saying. “But if you look at other health-related behaviors—like, do people brush and floss, do they wear seatbelts, or do they get preventive medical exams—over time, the rates of those things has improved or stayed the same.”
An inexpensive, over-the-counter drug often used as a treatment against parasitic worms is in high demand in Perú, Bolivia, Guatemala and other parts of Latin America as an unproven preventative for COVID-19, reports freelance science journalist Emiliano Rodríguez Mega for Nature (10/20/20). Little evidence suggests that the drug, called ivermectin, is effective, the story states. Now, the popularity of the drug makes it difficult for COVID-19 researchers to find potential study subjects who have not already taken it, Rodríguez Mega reports. The drug has been linked to tremors, convulsions, lethargy, and disorientation, as well as brain damage and comas in people with a certain genetic mutation, Rodríguez Mega writes. A global health researcher at Cayetano Heredia University in Perú is quoted as saying: “What we’re having is a populist treatment, instead of an evidence-based treatment.” Some researchers continue to try to recruit patients for small-scale or ongoing studies of the drug’s possible effectiveness against COVID-19, the story states.
Science magazine's Dance Your PhD competition is on, now with an additional COVID-19 category. The submission deadline is 1/29/21 (Science, 10/26/20).


scientificamerican--2020-10-31--NASA's OSIRIS-REx Probe Successfully Stows Space-Rock Sample

NASA ’ s pioneering OSIRIS-REx probe has bagged up its precious asteroid sample for return to Earth .
OSIRIS-REx has finished stowing the bits of the carbon-rich asteroid Bennu that it snagged last Tuesday ( Oct. 20 ) , successfully locking the material into the spacecraft ’ s return capsule , mission team members announced Thursday ( Oct. 29 ) .
And the sample appears to be substantial—far heftier than the 2.1 ounces ( 60 grams ) the mission had set as a target , team members said .
Indeed , OSIRIS-REx collected so much material on Oct. 20 that @ @ @ @ @ @ @ properly ; the head ’ s sealing mylar flap was wedged open in places by protruding Bennu pebbles .
The OSIRIS-REx team noticed that issue last week when examining photos of the head and its collected sample ; flakes of escaped asteroid material drifted through the frames .
To minimize the amount lost , the team decided to expedite the precise and complex stowing procedure , which was supposed to happen next week .
So , over the course of 36 hours on Tuesday and Wednesday ( Oct. 27 and Oct. 28 ) @ @ @ @ @ @ @ sampling head , which sat at the end of the probe ’ s robotic arm , into the return capsule ; tug on the head to make sure it was secured properly ; sever connections with the robotic arm ; and lock up the return capsule via the locking of two latches .
This was all done while OSIRIS-REx was about 205 million miles ( 330 million kilometers ) from Earth , meaning it took 18.5 minutes for each command to reach OSIRIS-REx , and another 18.5 minutes for each update from the @ @ @ @ @ @ @ .
“ We wanted to only attempt stow one time , and we wanted to make sure we were successful , ” OSIRIS-REx mission operations manager Sandra Freund , of Lockheed Martin Space in Littleton , Colorado , said during a NASA news conference Thursday .
“ And we definitely were.
” The change of plans required a last-minute reallocation of time on NASA ’ s Deep Space Network ( DSN ) , the system of radio telescopes that the agency uses to communicate with its far-flung probes .
Because the stow operation @ @ @ @ @ @ @ OSIRIS-REx needed a large block of continuous DSN time , which other NASA missions sacrificed for the greater good .
It ’ s unclear exactly how much asteroid material now sits in OSIRIS-REx ’ s return capsule , which will come down to Earth in September 2023 .
The team canceled a planned post-sampling weighing procedure that would have involved spinning the probe , because this maneuver would have resulted in more sample loss .
( Moving the arm—to photograph the sample and conduct the stow operation , for example—imparted grain-liberating acceleration , @ @ @ @ @ @ @ wanted to minimize such motions . )
But there ’ s definitely a lot of asteroid material on board , said mission principal investigator Dante Lauretta of the University of Arizona .
The sampling operation on Oct. 20 went extremely well , Lauretta said , and the head penetrated deep into Bennu ’ s surface—perhaps 19 inches ( 48 centimeters ) or more .
The team is confident that OSIRIS-REx pretty much filled its sampling head that day , meaning it likely backed away from Bennu with about 4.4 lbs .
( 2 @ @ @ @ @ @ @ losses over the ensuing days appear minimal by comparison—probably “ tens of grams ” in total , Lauretta said .
And recent photos of the sampling head showed that it was still packed .
Mission team members could only see 17 % of the head ’ s volume in those photos , but they estimate that about 14.1 ounces ( 400 g ) of Bennu material is jammed into that space , Lauretta said .
If that estimate is accurate , and if the 17 % slice is representative of the entire sampling @ @ @ @ @ @ @ onto more than 4.4 lbs .
( 2 kg ) of sample .
Lauretta ’ s overall prediction is more measured than that , but it ’ s still decidedly bullish .
“ I believe we still have hundreds of grams of material in the sample collector head—probably over a kilogram , easily , ” Lauretta said during today ’ s news conference .
That would be great news .
Such a large amount would allow lots of research groups to study the Bennu dirt and rock , and to perform a wide @ @ @ @ @ @ @ sample .
As an example , Lauretta pointed to organic chemistry—specifically , analyses involving sugars .
Sugars are “ expected to be present in very low abundances [ on asteroids like Bennu ] , requiring several grams of sample to extract them from , ” Lauretta said .
“ And we thought that would not be feasible with the 15-gram allocation but something that does open up with the larger mass available for analysis.
” If all goes according to plan , such experiments will reveal a great deal about the solar system @ @ @ @ @ @ @ that asteroids like Bennu may have played in helping life get going on Earth , by delivering lots of water and carbon-containing organic chemicals .
Shedding light on such big questions is the chief goal of the $ 800 million OSIRIS-REx mission , which launched in September 2016 and arrived at Bennu in December 2018 .
The mission ’ s next big steps involve gearing up for the return trip ( though engineers are also trying to figure out if they can somehow get a rough mass estimate of the now-stowed sample ) @ @ @ @ @ @ @ start heading for home between early March and May , and the current plan is to target the earliest part of that window , team members said today .
OSIRIS-REx is NASA ’ s first asteroid-sampling mission , but it ’ s not the first one in history .
Japan ’ s Hayabusa mission delivered small bits of the stony asteroid Itokawa to Earth in 2010 , and that probe ’ s successor , Hayabusa2 , is scheduled to return a sample of the carbon-rich asteroid Ryugu this coming December .
Copyright 2020 @ @ @ @ @ @ @ rights reserved .
This material may not be published , broadcast , rewritten or redistributed .

NASA’s pioneering OSIRIS-REx probe has bagged up its precious asteroid sample for return to Earth.
OSIRIS-REx has finished stowing the bits of the carbon-rich asteroid Bennu that it snagged last Tuesday (Oct. 20), successfully locking the material into the spacecraft’s return capsule, mission team members announced Thursday (Oct. 29).
And the sample appears to be substantial—far heftier than the 2.1 ounces (60 grams) the mission had set as a target, team members said. Indeed, OSIRIS-REx collected so much material on Oct. 20 that its sampling head couldn’t close properly; the head’s sealing mylar flap was wedged open in places by protruding Bennu pebbles.
The OSIRIS-REx team noticed that issue last week when examining photos of the head and its collected sample; flakes of escaped asteroid material drifted through the frames. To minimize the amount lost, the team decided to expedite the precise and complex stowing procedure, which was supposed to happen next week.
So, over the course of 36 hours on Tuesday and Wednesday (Oct. 27 and Oct. 28), engineers directed OSIRIS-REx to deposit the sampling head, which sat at the end of the probe’s robotic arm, into the return capsule; tug on the head to make sure it was secured properly; sever connections with the robotic arm; and lock up the return capsule via the locking of two latches.
This was all done while OSIRIS-REx was about 205 million miles (330 million kilometers) from Earth, meaning it took 18.5 minutes for each command to reach OSIRIS-REx, and another 18.5 minutes for each update from the probe to come back down to Earth.
“We wanted to only attempt stow one time, and we wanted to make sure we were successful,” OSIRIS-REx mission operations manager Sandra Freund, of Lockheed Martin Space in Littleton, Colorado, said during a NASA news conference Thursday. “And we definitely were.”
The change of plans required a last-minute reallocation of time on NASA’s Deep Space Network (DSN), the system of radio telescopes that the agency uses to communicate with its far-flung probes. Because the stow operation was so important and so involved, OSIRIS-REx needed a large block of continuous DSN time, which other NASA missions sacrificed for the greater good.
It’s unclear exactly how much asteroid material now sits in OSIRIS-REx’s return capsule, which will come down to Earth in September 2023. The team canceled a planned post-sampling weighing procedure that would have involved spinning the probe, because this maneuver would have resulted in more sample loss. (Moving the arm—to photograph the sample and conduct the stow operation, for example—imparted grain-liberating acceleration, mission team members explained. So they wanted to minimize such motions.)
But there’s definitely a lot of asteroid material on board, said mission principal investigator Dante Lauretta of the University of Arizona.
The sampling operation on Oct. 20 went extremely well, Lauretta said, and the head penetrated deep into Bennu’s surface—perhaps 19 inches (48 centimeters) or more. The team is confident that OSIRIS-REx pretty much filled its sampling head that day, meaning it likely backed away from Bennu with about 4.4 lbs. (2 kilograms) of collected material.
The losses over the ensuing days appear minimal by comparison—probably “tens of grams” in total, Lauretta said. And recent photos of the sampling head showed that it was still packed. Mission team members could only see 17% of the head’s volume in those photos, but they estimate that about 14.1 ounces (400 g) of Bennu material is jammed into that space, Lauretta said.
If that estimate is accurate, and if the 17% slice is representative of the entire sampling head, then OSIRIS-REx may have held onto more than 4.4 lbs. (2 kg) of sample. Lauretta’s overall prediction is more measured than that, but it’s still decidedly bullish.
“I believe we still have hundreds of grams of material in the sample collector head—probably over a kilogram, easily,” Lauretta said during today’s news conference.
That would be great news. Such a large amount would allow lots of research groups to study the Bennu dirt and rock, and to perform a wide variety of experiments with the pristine cosmic sample. As an example, Lauretta pointed to organic chemistry—specifically, analyses involving sugars.
Sugars are “expected to be present in very low abundances [on asteroids like Bennu], requiring several grams of sample to extract them from,” Lauretta said. “And we thought that would not be feasible with the 15-gram allocation but something that does open up with the larger mass available for analysis.”
(The OSIRIS-REx science team gets to analyze up to 25% of the returned sample. If the total sample ended up being the targeted 60 grams, the team would get to study up to 15 grams of it.)
If all goes according to plan, such experiments will reveal a great deal about the solar system’s early days and the role that asteroids like Bennu may have played in helping life get going on Earth, by delivering lots of water and carbon-containing organic chemicals. Shedding light on such big questions is the chief goal of the $800 million OSIRIS-REx mission, which launched in September 2016 and arrived at Bennu in December 2018.
The mission’s next big steps involve gearing up for the return trip (though engineers are also trying to figure out if they can somehow get a rough mass estimate of the now-stowed sample). Orbital dynamics dictate that OSIRIS-REx must start heading for home between early March and May, and the current plan is to target the earliest part of that window, team members said today.
OSIRIS-REx is NASA’s first asteroid-sampling mission, but it’s not the first one in history. Japan’s Hayabusa mission delivered small bits of the stony asteroid Itokawa to Earth in 2010, and that probe’s successor, Hayabusa2, is scheduled to return a sample of the carbon-rich asteroid Ryugu this coming December.
Copyright 2020 Space.com, a Future company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


scientificamerican--2020-10-31--Deliberate Efforts to Achieve Herd Immunity to COVID Are Dangerous

The following essay is reprinted with permission from The Conversation , an online publication covering the latest research .
White House advisers have made the case recently for a “ natural ” approach to herd immunity as a way to reduce the need for public health measures to control the SARS-CoV-2 pandemic while still keeping people safe .
This idea is summed up in something called the Great Barrington Declaration , a proposal put out by the American Institute for Economic Research , a libertarian think tank .
The basic idea behind this proposal is to let low-risk people in @ @ @ @ @ @ @ with the coronavirus , while vulnerable people would maintain social distancing and continue to shelter in place .
Proponents of this strategy claim so-called “ natural herd immunity ” will emerge and minimize harm from SARS-CoV-2 while protecting the economy .
Another way to get to herd immunity is through mass vaccinations , as we have done with measles , smallpox and largely with polio .
A population has achieved herd immunity when a large enough percentage of individuals become immune to a disease .
When this happens , infected people are no @ @ @ @ @ @ @ and the epidemic will burn out .
As a professor of behavioral and community health sciences , I am acutely aware that mental , social and economic health are important for a person to thrive , and that public health measures such as social distancing have imposed severe restrictions on daily life .
But based on all the research and science available , the leadership at the University of Pittsburgh Graduate School of Public Health and I believe this infection-based approach would almost certainly fail .
Dropping social distancing and mask wearing , @ @ @ @ @ @ @ result in overwhelmed hospital systems and skyrocketing mortality .
Furthermore , according to recent research , this reckless approach is unlikely to even produce the herd immunity that ’ s the whole point of such a plan .
Vaccination , in comparison , offers a much safer and likely more effective approach .
Herd immunity is an effective way to limit a deadly epidemic , but it requires a huge number of people to be immune .
The proportion of the population required for herd immunity depends on how infectious a virus is @ @ @ @ @ @ @ reproduction number , R0 , how many people a single contagious person would infect in a susceptible population .
For SARS-CoV-2 , R0 is between 2 and 3.2 .
At that level of infectiousness , between 50 % and 67 % of the population would need to develop immunity through exposure or vaccination to contain the pandemic .
The Great Barrington Declaration suggests the U.S. should aim for this immune threshold through infection rather than vaccination .
To get to 60 % immunity in the U.S. , about 198 million individuals would need @ @ @ @ @ @ @ resistance to the coronavirus .
The demand on hospital care from infections would be overwhelming .
And according to the WHO estimated infection fatality rate of 0.5 % , that would mean nearly a million deaths if the country were to open up fully .
The Great Barrington Declaration hinges on the idea that you can effectively keep healthy , infected people away from those who are at higher risk .
According to this plan , if only healthy people are exposed to the virus , then the U.S. could get to herd @ @ @ @ @ @ @ may sound reasonable , but in the real world with this particular virus , such a plan is simply not possible and ignores the risks to vulnerable people , young and old .
The Great Barrington Declaration calls for “ allowing those who are at minimal risk of death to live their lives normally … while protecting those who are at highest risk.
” Yet healthy people can get sick , and asymptomatic transmission , inadequate testing and difficulty isolating vulnerable people pose severe challenges to a neat separation based on risk .
@ @ @ @ @ @ @ all healthy people can survive a coronavirus infection .
Though at-risk groups do worse , young healthy people are also dying and facing long-term issues from the illness .
Second , not all high-risk people can self-isolate .
In some areas , as much as 22 % of the population have two or more chronic conditions that put them at higher risk for severe COVID-19 .
They might live with someone in the low-risk group and they still must shop , work and do the other activities necessary for life .
High-risk individuals @ @ @ @ @ @ @ group .
So can you simply guarantee that the low-risk people who interact with the high-risk group are uninfected ?
People who are infected but not showing symptoms may account for more than 30 % of transmission .
This asymptomatic spread is hard to detect .
Asymptomatic spread is compounded by shortcomings in the quality of testing .
Currently available tests are fairly good , but do not reliably detect the coronavirus during the early phase of infection when viral concentrations can be low .
Accordingly , identifying infection in the low-risk population @ @ @ @ @ @ @ go on to infect high-risk populations because it is impossible to prevent contact between them .
Without sharp isolation of these two populations , uncontrolled transmission in younger , healthier people risks significant illness and death across vulnerable populations .
Both computer models and one real-world experiment back up these fears .
A recent U.K. modeling effort assessed a range of relaxed suppression strategies and showed that none achieved herd immunity while also keeping cases below hospital capacity .
This study estimated a fourfold increase in mortality among older people if only older @ @ @ @ @ @ @ of the population does not .
But epidemiologists don ’ t have to rely on computer models alone .
Sweden tried this approach to infection-based herd immunity .
It did not go well .
Sweden ’ s mortality rate is on par with Italy ’ s and substantially higher than its neighbors .
Despite this risky approach , Sweden ’ s economy still suffered , and on top of that , nowhere near enough Swedes have been infected to get to herd immunity .
As of August 2020 , only about 7.1 % @ @ @ @ @ @ @ , with the highest rate of 11.4 % in Stockholm .
This is far short of the estimated 50 % -67 % required to achieve herd immunity to the coronavirus .
There is one final reason to doubt the efficacy of infection-based herd immunity : Contracting and recovering from the coronavirus might not even give immunity for very long .
One CDC report suggests that “ people appear to become susceptible to reinfection around 90 days after onset of infection.
” The potentially short duration of immunity in some recovered patients would certainly @ @ @ @ @ @ @ .
When combined with the fact that the highest estimates for antibody prevalence suggest that less than 10 % of the U.S. population has been infected , it would be a long , dangerous and potentially impassable road to infection-based herd immunity .
But there is another way , one that has been done before : mass vaccination .
Vaccine-induced herd immunity can end this pandemic the same way it has mostly ended measles , eradicated smallpox and nearly eradicated polio across the globe .
Vaccines work .
Until mass SARS-CoV-2 vaccination , @ @ @ @ @ @ @ , with comprehensive case finding , testing , tracing and isolation , are the safest approach .
These tried-and-true public health measures will keep viral transmission low enough for people to work and attend school while managing smaller outbreaks as they arise .
It isn ’ t a return to a totally normal life , but these approaches can balance social and economic needs with health .
And then , once a vaccine is widely available , the country can move to herd immunity .
This article was originally published on The Conversation @ @ @ @ @ @

The following essay is reprinted with permission from The Conversation, an online publication covering the latest research.
White House advisers have made the case recently for a “natural” approach to herd immunity as a way to reduce the need for public health measures to control the SARS-CoV-2 pandemic while still keeping people safe. This idea is summed up in something called the Great Barrington Declaration, a proposal put out by the American Institute for Economic Research, a libertarian think tank.
The basic idea behind this proposal is to let low-risk people in the U.S. socialize and naturally become infected with the coronavirus, while vulnerable people would maintain social distancing and continue to shelter in place. Proponents of this strategy claim so-called “natural herd immunity” will emerge and minimize harm from SARS-CoV-2 while protecting the economy.
Another way to get to herd immunity is through mass vaccinations, as we have done with measles, smallpox and largely with polio.
A population has achieved herd immunity when a large enough percentage of individuals become immune to a disease. When this happens, infected people are no longer able to transmit the disease, and the epidemic will burn out.
As a professor of behavioral and community health sciences, I am acutely aware that mental, social and economic health are important for a person to thrive, and that public health measures such as social distancing have imposed severe restrictions on daily life. But based on all the research and science available, the leadership at the University of Pittsburgh Graduate School of Public Health and I believe this infection-based approach would almost certainly fail.
Dropping social distancing and mask wearing, reopening restaurants and allowing large gatherings will result in overwhelmed hospital systems and skyrocketing mortality. Furthermore, according to recent research, this reckless approach is unlikely to even produce the herd immunity that’s the whole point of such a plan.
Vaccination, in comparison, offers a much safer and likely more effective approach.
An uncertain path to herd immunity
Herd immunity is an effective way to limit a deadly epidemic, but it requires a huge number of people to be immune.
The proportion of the population required for herd immunity depends on how infectious a virus is. This is measured by the basic reproduction number, R0, how many people a single contagious person would infect in a susceptible population. For SARS-CoV-2, R0 is between 2 and 3.2. At that level of infectiousness, between 50% and 67% of the population would need to develop immunity through exposure or vaccination to contain the pandemic.
The Great Barrington Declaration suggests the U.S. should aim for this immune threshold through infection rather than vaccination.
To get to 60% immunity in the U.S., about 198 million individuals would need to be infected, survive and develop resistance to the coronavirus. The demand on hospital care from infections would be overwhelming. And according to the WHO estimated infection fatality rate of 0.5%, that would mean nearly a million deaths if the country were to open up fully.
The Great Barrington Declaration hinges on the idea that you can effectively keep healthy, infected people away from those who are at higher risk. According to this plan, if only healthy people are exposed to the virus, then the U.S. could get to herd immunity and avoid mass deaths. This may sound reasonable, but in the real world with this particular virus, such a plan is simply not possible and ignores the risks to vulnerable people, young and old.
You can’t fully isolate high-risk populations
The Great Barrington Declaration calls for “allowing those who are at minimal risk of death to live their lives normally … while protecting those who are at highest risk.” Yet healthy people can get sick, and asymptomatic transmission, inadequate testing and difficulty isolating vulnerable people pose severe challenges to a neat separation based on risk.
First, the plan wrongly assumes that all healthy people can survive a coronavirus infection. Though at-risk groups do worse, young healthy people are also dying and facing long-term issues from the illness.
Second, not all high-risk people can self-isolate. In some areas, as much as 22% of the population have two or more chronic conditions that put them at higher risk for severe COVID-19. They might live with someone in the low-risk group and they still must shop, work and do the other activities necessary for life. High-risk individuals will come in contact with the low-risk group.
So can you simply guarantee that the low-risk people who interact with the high-risk group are uninfected? People who are infected but not showing symptoms may account for more than 30% of transmission. This asymptomatic spread is hard to detect.
Asymptomatic spread is compounded by shortcomings in the quality of testing. Currently available tests are fairly good, but do not reliably detect the coronavirus during the early phase of infection when viral concentrations can be low.
Accordingly, identifying infection in the low-risk population would be difficult. These people could go on to infect high-risk populations because it is impossible to prevent contact between them.
Sweden’s herd immunity failure
Without sharp isolation of these two populations, uncontrolled transmission in younger, healthier people risks significant illness and death across vulnerable populations. Both computer models and one real-world experiment back up these fears.
A recent U.K. modeling effort assessed a range of relaxed suppression strategies and showed that none achieved herd immunity while also keeping cases below hospital capacity. This study estimated a fourfold increase in mortality among older people if only older people practice social distancing and the remainder of the population does not.
But epidemiologists don’t have to rely on computer models alone. Sweden tried this approach to infection-based herd immunity. It did not go well. Sweden’s mortality rate is on par with Italy’s and substantially higher than its neighbors. Despite this risky approach, Sweden’s economy still suffered, and on top of that, nowhere near enough Swedes have been infected to get to herd immunity. As of August 2020, only about 7.1% of the country had contracted the virus, with the highest rate of 11.4% in Stockholm. This is far short of the estimated 50%-67% required to achieve herd immunity to the coronavirus.
Exposure versus vaccination
There is one final reason to doubt the efficacy of infection-based herd immunity: Contracting and recovering from the coronavirus might not even give immunity for very long. One CDC report suggests that “people appear to become susceptible to reinfection around 90 days after onset of infection.” The potentially short duration of immunity in some recovered patients would certainly throw a wrench in such a plan. When combined with the fact that the highest estimates for antibody prevalence suggest that less than 10% of the U.S. population has been infected, it would be a long, dangerous and potentially impassable road to infection-based herd immunity.
But there is another way, one that has been done before: mass vaccination. Vaccine-induced herd immunity can end this pandemic the same way it has mostly ended measles, eradicated smallpox and nearly eradicated polio across the globe. Vaccines work.
Until mass SARS-CoV-2 vaccination, social distancing and use of face coverings, with comprehensive case finding, testing, tracing and isolation, are the safest approach. These tried-and-true public health measures will keep viral transmission low enough for people to work and attend school while managing smaller outbreaks as they arise. It isn’t a return to a totally normal life, but these approaches can balance social and economic needs with health. And then, once a vaccine is widely available, the country can move to herd immunity.
This article was originally published on The Conversation. Read the original article.


scientificamerican--2020-10-31--Rapid Heat-Stress Test Identifies Resilient Corals

As rising ocean temperatures threaten coral reefs worldwide , identifying the most heat-resilient coral colonies is crucial for conservation efforts .
Typical methods require flying samples to distant laboratories and subjecting them to high temperatures for weeks .
Now a new heat-stress test brings the lab to the reef , yielding results within a single day .
The Coral Bleaching Automated Stress System ( CBASS ) , made from materials commonly available at hardware stores , consists of four 10-liter tanks that can be set up on the same boats researchers use to reach the reefs .
“ You just @ @ @ @ @ @ @ corals , and put them into the tanks and get everything started , ” says Carol Buitrago López , a graduate student at King Abdullah University of Science and Technology ( KAUST ) in Saudi Arabia .
She and her colleagues described CBASS in August in Global Change Biology .
The team placed finger-sized coral samples from two Red Sea sites into CBASS tanks at a baseline temperature of 30 degrees Celsius ( 86 degrees Fahrenheit ) .
Over three hours the system increased each tank 's temperature to a different value—39 degrees @ @ @ @ @ @ @ for another three hours , dropping it back to 30 over the next hour .
Finally , the scientists gave the corals 11 more hours to recover .
They used a flashlightlike device to measure how efficiently the microalgae in the corals used light when photosynthesizing ( a well-established indicator of a plant 's stress level ) .
This short-term measurement aligned with the results from a traditional long-term heat-stress experiment , showing the method 's potential to rapidly identify resilient corals .
“ I would love to adopt [ CBASS ] in @ @ @ @ @ @ @ , who researches coral genetics at the University of Texas at Austin and was not involved with the study .
“ The whole simplicity of this approach is very appealing.
” Although coral reefs are too vast to test in their entirety , researchers can harness CBASS 's speed to measure targeted coral samples at a scale not previously possible .
In a follow-up experiment , “ we measured 500 corals in two weeks , ” says Christian Voolstra , a researcher at KAUST and the University of Konstanz in Germany and lead @ @ @ @ @ @ @ Traditionally this would be your lifetime as a professor.
” Whether the corals that perform best in CBASS experiments will indeed withstand climate change remains an open question , Matz cautions .
Still , he says , CBASS 's standardized procedure will let researchers directly compare the heat tolerances of coral colonies around the world , a key step in restoration efforts .
Conservation scientists commonly grow coral fragments in a nursery and then transfer them to degraded reef systems .
So far such “ outplanting ” projects have met with limited success @ @ @ @ @ @ @ , Voolstra says , could help buy time until climate change can be brought under control .

As rising ocean temperatures threaten coral reefs worldwide, identifying the most heat-resilient coral colonies is crucial for conservation efforts. Typical methods require flying samples to distant laboratories and subjecting them to high temperatures for weeks. Now a new heat-stress test brings the lab to the reef, yielding results within a single day.
The Coral Bleaching Automated Stress System (CBASS), made from materials commonly available at hardware stores, consists of four 10-liter tanks that can be set up on the same boats researchers use to reach the reefs. “You just jump into the water, get the corals, and put them into the tanks and get everything started,” says Carol Buitrago López, a graduate student at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia. She and her colleagues described CBASS in August in Global Change Biology.
The team placed finger-sized coral samples from two Red Sea sites into CBASS tanks at a baseline temperature of 30 degrees Celsius (86 degrees Fahrenheit). Over three hours the system increased each tank's temperature to a different value—39 degrees C was the maximum—then held there it for another three hours, dropping it back to 30 over the next hour. Finally, the scientists gave the corals 11 more hours to recover. They used a flashlightlike device to measure how efficiently the microalgae in the corals used light when photosynthesizing (a well-established indicator of a plant's stress level). This short-term measurement aligned with the results from a traditional long-term heat-stress experiment, showing the method's potential to rapidly identify resilient corals.
“I would love to adopt [CBASS] in my research,” says Mikhail Matz, who researches coral genetics at the University of Texas at Austin and was not involved with the study. “The whole simplicity of this approach is very appealing.” Although coral reefs are too vast to test in their entirety, researchers can harness CBASS's speed to measure targeted coral samples at a scale not previously possible. In a follow-up experiment, “we measured 500 corals in two weeks,” says Christian Voolstra, a researcher at KAUST and the University of Konstanz in Germany and lead author of the new paper. “Traditionally this would be your lifetime as a professor.”
Whether the corals that perform best in CBASS experiments will indeed withstand climate change remains an open question, Matz cautions. Still, he says, CBASS's standardized procedure will let researchers directly compare the heat tolerances of coral colonies around the world, a key step in restoration efforts. Conservation scientists commonly grow coral fragments in a nursery and then transfer them to degraded reef systems. So far such “outplanting” projects have met with limited success. But outplanting the most heat-tolerant corals, Voolstra says, could help buy time until climate change can be brought under control.


scientificamerican--2020-10-31--How Geologists Reveal the Secrets of the Solar System

Of all the sciences , astronomy has shed particularly brilliant light on our place in the universe .
But it is not well-known that much of our understanding of outer space comes from a different discipline altogether : geology .
Ask somebody to name a tool that we use to uncover the secrets of the cosmos , and they ’ ll likely say telescope rather than microscope or rock hammer .
But if you think about it , pretty much anything we can get our hands on that comes from outer space is a rock .
Yes , scraps of @ @ @ @ @ @ @ Earth ; and yes , particles from the solar wind were safely returned to Earth by NASA ’ s Genesis mission in 2004 .
But the amount of extraterrestrial rock that we have on Earth exceeds the lot .
We have rock from the moon , thanks to the Apollo and Luna missions ; we also have moon rocks and rocks from Mars that were blasted into space by asteroid impacts on these bodies surfaces , and eventually wandered close to our planet and fell to Earth as meteorites .
We have rocks @ @ @ @ @ @ @ ; and from the asteroid belt , from to the pitter-patter of meteorites that rain from the skies .
We could soon have rocks from asteroid Bennu , now that NASA ’ s sample-return mission OSIRIS-Rex has made a successful touchdown .
And we can study the remnants of impact craters created by asteroids striking Earth ’ s surface at hypersonic velocity .
In fact , rocks are practically the only way we can hold pieces of outer space .
Telescopes and robotic space missions , powerful as they are , can only @ @ @ @ @ @ @ celestial rocks—particularly meteorites—we have learned about the solar system and beyond .
While meteorites have a special place in many a heart ( mine included ) , they are still rocks , and as the old saying goes , nobody knows a rock better than a geologist .
And so , just like we would with any old Earth rock , we use the tools of geology to understand the ones that come from space .
All stars begin their lives when interstellar nebulae collapse under gravity ; the densest part , at @ @ @ @ @ @ @ ; the rest forms a rotating , pancake-shaped cloud of gas and dust known as a protoplanetary disk .
These disks begin crystallizing into microscopic motes of rocky dust , which eventually coalesce to form asteroids , comets and planets .
We have telescopic observations of this process happening in real time from telescopes like ALMA and Hubble , but there is only so much we can learn from light-years away .
Meteorites give us a microscopic insight into the protoplanetary disk from which our solar system formed , because many still preserve @ @ @ @ @ @ @ It is no stretch to say that they are pieces of the disk .
Amongst the first to recognize this was English geologist Henry Clifton Sorby , who , in a lecture in 1877 , said that “ meteorites are the residual cosmical matter , not collected into planets.
” He came to this startling conclusion using the knowledge and skills he had gained by studying Earthly rocks down the barrel of a geological microscope .
Sorby ’ s great insight transformed our view of meteorites and the solar system forever .
By @ @ @ @ @ @ @ the laboratory over the past 150 years , we have come to know their geological characters , and from them we have inferred with confidence the sorts of environments that existed in our own nascent solar system and other solar systems across the galaxy .
Without meteorites and knowledge of how Earthly rocks form , these long-lost environments would be entirely out of our reach , and the mechanisms by which clockworklike systems of planets form would be almost impossible to pin down .
Since they ’ re made from the primordial , @ @ @ @ @ @ @ literally get our hands on .
By dating them , we have put a high-precision timescale to the infant solar system and the events that unfolded within it .
We date meteorites using the same tool of geology that we use to date Earthly rocks : radioactive dating .
In fact , the age of the solar system itself—4,567,000,000 years ( that ’ s 4.567 billion years ) old—is defined by the radioactive decay of uranium into lead inside meteorites .
Geologists who specialize in dating rocks ( geochronologists ) have measured this @ @ @ @ @ @ @ to knowing the distance from Manchester , U.K. , to New York City to within a few hundred meters ) .
Closer to home , geologists—perhaps none more famous than the late Eugene “ Gene ” Shoemaker—have played a crucial role in understanding our own planet ’ s place in space .
In the 1950s , Shoemaker , a geologist by training , and his colleagues discovered shocked quartz ( a mineral that only forms under the extreme pressures caused by impacts from space ) in the rocks surrounding Barringer Crater ( aka @ @ @ @ @ @ @ and became the first to definitively prove its extraterrestrial origin from an asteroid collision with Earth .
( At the time , there was a controversy as to whether the crater was caused by an asteroid or was simply the vent of an extinct volcano ) .
Geological mapping and the discovery of more shocked quartz also led Shoemaker and his colleagues to identify a second impact crater : the 15-mile wide Nördlinger Ries impact crater in Bavaria , Germany .
Shoemaker ’ s research into terrestrial impact craters led him in the @ @ @ @ @ @ @ the moon ’ s craters were formed by impacts : today , we know he was right , and recognise that the moon ’ s surface is indeed peppered by scars from impacts from space .
We have Shoemaker to thank in part for the Apollo moon rocks , too .
Using his geological field skills , he trained the astronauts how to collect rock samples ; those samples the astronauts brought back have revolutionized our view of the moon .
( On that note , the only scientist ever to walk on @ @ @ @ @ @ @ Schmitt , who rode there aboard Apollo 17 , the last of the series , was a geologist ) .
In 1997 , Shoemaker became the first ( and still only ) person to be laid to rest on the moon , when some of his ashes were sent to the moon on board the Lunar Prospector spacecraft .
And so , with that , I ’ ll rephrase the old saying : nobody knows a space rock better than a geologist .
And , as it turns out , space rocks ( @ @ @ @ @ @ @ impact craters , when viewed through a geological lens , have a lot to tell us about the cosmos .

Of all the sciences, astronomy has shed particularly brilliant light on our place in the universe. But it is not well-known that much of our understanding of outer space comes from a different discipline altogether: geology. Ask somebody to name a tool that we use to uncover the secrets of the cosmos, and they’ll likely say telescope rather than microscope or rock hammer.
But if you think about it, pretty much anything we can get our hands on that comes from outer space is a rock. Yes, scraps of space hardware are sometimes safely returned to Earth; and yes, particles from the solar wind were safely returned to Earth by NASA’s Genesis mission in 2004. But the amount of extraterrestrial rock that we have on Earth exceeds the lot. We have rock from the moon, thanks to the Apollo and Luna missions; we also have moon rocks and rocks from Mars that were blasted into space by asteroid impacts on these bodies surfaces, and eventually wandered close to our planet and fell to Earth as meteorites. We have rocks from comets thanks to the Stardust mission; and from the asteroid belt, from to the pitter-patter of meteorites that rain from the skies. We could soon have rocks from asteroid Bennu, now that NASA’s sample-return mission OSIRIS-Rex has made a successful touchdown. And we can study the remnants of impact craters created by asteroids striking Earth’s surface at hypersonic velocity.
PIECES OF THE NASCENT SOLAR SYSTEM
In fact, rocks are practically the only way we can hold pieces of outer space. Telescopes and robotic space missions, powerful as they are, can only take us so far, and from celestial rocks—particularly meteorites—we have learned about the solar system and beyond. While meteorites have a special place in many a heart (mine included), they are still rocks, and as the old saying goes, nobody knows a rock better than a geologist. And so, just like we would with any old Earth rock, we use the tools of geology to understand the ones that come from space.
All stars begin their lives when interstellar nebulae collapse under gravity; the densest part, at the center, becomes the star itself; the rest forms a rotating, pancake-shaped cloud of gas and dust known as a protoplanetary disk. These disks begin crystallizing into microscopic motes of rocky dust, which eventually coalesce to form asteroids, comets and planets. We have telescopic observations of this process happening in real time from telescopes like ALMA and Hubble, but there is only so much we can learn from light-years away.
Meteorites give us a microscopic insight into the protoplanetary disk from which our solar system formed, because many still preserve these primordial motes of rocky dust. It is no stretch to say that they are pieces of the disk. Amongst the first to recognize this was English geologist Henry Clifton Sorby, who, in a lecture in 1877, said that “meteorites are the residual cosmical matter, not collected into planets.” He came to this startling conclusion using the knowledge and skills he had gained by studying Earthly rocks down the barrel of a geological microscope. Sorby’s great insight transformed our view of meteorites and the solar system forever.
By teasing apart these motes of dust in the laboratory over the past 150 years, we have come to know their geological characters, and from them we have inferred with confidence the sorts of environments that existed in our own nascent solar system and other solar systems across the galaxy. Without meteorites and knowledge of how Earthly rocks form, these long-lost environments would be entirely out of our reach, and the mechanisms by which clockworklike systems of planets form would be almost impossible to pin down.
Since they’re made from the primordial, meteorites are the oldest objects we can literally get our hands on. By dating them, we have put a high-precision timescale to the infant solar system and the events that unfolded within it. We date meteorites using the same tool of geology that we use to date Earthly rocks: radioactive dating. In fact, the age of the solar system itself—4,567,000,000 years (that’s 4.567 billion years) old—is defined by the radioactive decay of uranium into lead inside meteorites. Geologists who specialize in dating rocks (geochronologists) have measured this age to plus or minus 160,000 years—equivalent to knowing the distance from Manchester, U.K., to New York City to within a few hundred meters).
A BIG IMPACT
Closer to home, geologists—perhaps none more famous than the late Eugene “Gene” Shoemaker—have played a crucial role in understanding our own planet’s place in space. In the 1950s, Shoemaker, a geologist by training, and his colleagues discovered shocked quartz (a mineral that only forms under the extreme pressures caused by impacts from space) in the rocks surrounding Barringer Crater (aka “Meteor Crater”) in Arizona and became the first to definitively prove its extraterrestrial origin from an asteroid collision with Earth. (At the time, there was a controversy as to whether the crater was caused by an asteroid or was simply the vent of an extinct volcano). Geological mapping and the discovery of more shocked quartz also led Shoemaker and his colleagues to identify a second impact crater: the 15-mile wide Nördlinger Ries impact crater in Bavaria, Germany. Shoemaker’s research into terrestrial impact craters led him in the 1960s to resurrect an old idea that the moon’s craters were formed by impacts: today, we know he was right, and recognise that the moon’s surface is indeed peppered by scars from impacts from space.
We have Shoemaker to thank in part for the Apollo moon rocks, too. Using his geological field skills, he trained the astronauts how to collect rock samples; those samples the astronauts brought back have revolutionized our view of the moon. (On that note, the only scientist ever to walk on the moon, Harrison “Jack” Schmitt, who rode there aboard Apollo 17, the last of the series, was a geologist).
In 1997, Shoemaker became the first (and still only) person to be laid to rest on the moon, when some of his ashes were sent to the moon on board the Lunar Prospector spacecraft.
And so, with that, I’ll rephrase the old saying: nobody knows a space rock better than a geologist. And, as it turns out, space rocks (meteorites and moon rocks alike) and impact craters, when viewed through a geological lens, have a lot to tell us about the cosmos.