scientificamerican--2020-12-08--To Control COVID, Biden Needs to Marshal Federal Resources--and Change Attitudes

As I write , the U.S. has entered a dire phase of the COVID-19 pandemic .
Infections are rising in nearly every state , more than 100,000 people are hospitalized , and deaths have topped 280,000—the highest total in the world .
The crush of patients is overwhelming hospitals and , almost a year into the catastrophe , their health workers still do not have enough medical-grade masks .
The Trump administration has actively resisted some of the most important measures to contain COVID , such as prompt testing and tracing of cases and mask wearing .
Donald Trump himself @ @ @ @ @ @ @ , instead hyping false claims about voter fraud in the election he lost .
Though effective vaccines are arriving for some high-priority groups , the country is facing a dark , tragic winter .
It ’ s hard to imagine a starker contrast to the approach announced by Trump ’ s successor .
Within a week of the election , President-elect Joe Biden and Vice President-elect Kamala Harris assembled a coronavirus task force of respected scientists and public health experts , and outlined a COVID-19 plan .
That plan aims to scale up @ @ @ @ @ @ @ and local mask mandates , boost production of personal protective equipment ( PPE ) , provide economic support for small businesses that have had to curtail activity or close , give money to schools , ensure a smooth and trustworthy vaccine rollout , protect high-risk groups , address racial and ethnic disparities in COVID ’ s impact , and prepare for the next pandemic .
Some of these goals likely will face severe headwinds from Republicans in Congress and among those who voted for Trump .
Both groups , for instance , have @ @ @ @ @ @ @ restrictions , often on economic grounds .
Biden ’ s answer is to say he is “ not going to shut down the economy—period .
I am going to shut down the virus.
” The incoming administration sees restrictions as a “ dial , ” rather than an on-off switch .
“ That ’ s a perfect metaphor , ” says Monica Gandhi , a professor at the University of California ’ s UCSF School of Medicine .
“ It ’ s triggering to use the word ‘ lockdown.
’ ” The president-elect @ @ @ @ @ @ @ Disease Control and Prevention to provide guidelines for ways to dial up or down restrictions on businesses , schools and gatherings .
The evidence is clear that a lot of COVID transmission occurs at restaurants , bars and gyms , but not so much at schools , so it makes sense to dial down restrictions on the latter , Gandhi says .
Of course , restrictions that affect people ’ s livelihoods need to be coupled with federal government support for workers and employers .
Biden has said he would seek more funding @ @ @ @ @ @ @ in Congress have already signaled they would oppose a large new pandemic relief bill—especially if they hold onto their majority in the Senate after Georgia runoff elections in early January .
So any money Congress offers will probably be less than what Biden asks for .
Still , there are a few highly effective measures Biden can take that do not require Congressional sign-off .
Nearly every expert I spoke with agreed that that one of the simplest and most important things Biden ’ s team can do is encourage people to wear @ @ @ @ @ @ @ extensive evidence supporting their effectiveness , Trump made it a political statement not to wear one , mocking people—including Biden—for using them .
Biden can try to change that .
“ President-elect Biden and Vice President-elect Harris have always modeled responsible behavior throughout the campaign , ” Robert Rodriguez , an emergency physician at the UCSF School of Medicine and a member of the Biden-Harris administration ’ s coronavirus task force , told me .
“ They ’ re going to continue to promote the concept that wearing masks is noble–it ’ s @ @ @ @ @ @ @ about the country and about others.
” Because masks have become so political , however , the messaging needs to strike a careful balance , Gandhi says .
Like “ lockdown , ” the phrase “ mask mandate ” seems to really rile people up , she says , “ whereas ‘ mask guidance ’ doesn ’ t. ” Biden plans to work with governors and mayors to implement state and local mask rules .
And he does intend to make masks mandatory in federal buildings and on interstate public transportation .
A @ @ @ @ @ @ @ some people ’ s reluctance to get a coronavirus vaccine when shots become widely available , later in 2021 .
Refusals will prolong the outbreak .
Only 32 percent of Black Americans said they would get a shot if one were available ( according to a Pew survey in September ) , down from 54 percent in May .
Much of this resistance stems from a history of racism and mistreatment of Black people in medicine .
“ We can ’ t do anything without first reconciling that history , ” says Nneka @ @ @ @ @ @ @ Children ’ s Minnesota , whose work focuses on health equity .
Biden and his officials need to admit there is legitimate reason for distrust , and work to earn it back .
The Biden-Harris administration saying , ‘ we ’ re acknowledging that history of racism ourselves ’ is the most important thing they can do , Sederstrom says .
In order to convince skeptical populations , the new president and his team also need to reach out to community leaders who already have the trust of their constituents , she adds @ @ @ @ @ @ @ the works .
“ We ’ re developing robust plans to engage with communities on a national and local level , ” he says .
“ It is a challenge .
But our team has a lot of expertise in that arena.
” The task force is co-led by Marcella Nunez-Smith , a professor of internal medicine , public health and management at Yale School of Medicine , whose work focuses on promoting health equity in marginalized populations .
The administration has also said it plans to address the pandemic ’ s unequal @ @ @ @ @ @ @ a separate COVID racial and ethnic disparities task force , headed by Vice President-elect Harris .
Vaccine skepticism also extends to political affiliation .
Just 44 percent of Republicans or Republican-leaners said they would likely get vaccinated , compared with 58 percent of Democrats or Democrat-leaners , according to the September Pew survey .
To reach Republicans , Biden will need to reach out to conservative leaders as well .
Both vaccine acceptance and mask wearing depend on the new president ’ s ability to restore trust in science .
“ One of @ @ @ @ @ @ @ been lost is [ the Trump administration ] essentially not letting science and scientists direct the pandemic response efforts , ” says Angela Rasmussen , a virologist and affiliate researcher at the Georgetown Center for Global Health Science and Security .
Political meddling at government health agencies and repeated announcements that undercut public health measures exacerbated the problem .
It will be very difficult to overcome , she says .
Nevertheless , the Biden team can start to reverse the damage by showing that it is following scientific advice and delivering it in @ @ @ @ @ @ @ says .
“ Some of that trust will be earned back , but it 's not going to happen overnight.
” Beyond winning back trust , Biden needs to scale up COVID testing .
Before vaccines reach most Americans , the virus will still be spreading , and testing is the way to identify and contain outbreaks .
Frequent testing and isolation of positive cases is an effective strategy for preventing flareups on college campuses .
Yet it is still hard for Americans to get a test and get results quickly .
Biden @ @ @ @ @ @ @ number of places for individuals to get a diagnostic molecular test ( something he has promised to do in part by doubling the number of drive-through testing sites ) .
A national pandemic testing board , akin to the War Production Board President Franklin D. Roosevelt created during World War II , can marshal resources for this , and Biden has said he plans to create one .
Another promising approach is to get companies to produce millions of so-called “ rapid antigen ” tests .
These are less able to detect miniscule @ @ @ @ @ @ @ , but do work well when people are most infectious .
They can be taken at home or at a local testing site and yield results in 24 hours or less .
The U.S. Food and Drug Administration ( FDA ) has authorized seven such tests to date , but they are not widely available .
Michael Mina , an epidemiologist at Harvard University ’ s T. H. Chan School of Public Health , has been an avid proponent of producing tens of millions of them for at-home use .
“ We have @ @ @ @ @ @ @ s frequency of testing , not sensitivity ” that matters , he says .
“ You could have the best test in the world , but if it ’ s not available or it takes four days , it ’ s not useful.
” Mina says the biggest barrier to widespread rapid tests is that companies must develop these assays on their own and go through the FDA ’ s typical , slow approval process .
Instead , he says , the Biden administration should work directly with companies to develop and produce @ @ @ @ @ @ @ contracts with Lockheed Martin and Raytheon to produce airplanes and military equipment .
The tests should then be made freely available to homes , schools and businesses .
Others , though , say test expansion needs an additional component to avoid confusing people .
“ Rolling out self-testing should be done with a lot of education , ” Gandhi says .
Getting a false positive or false negative result “ can lead to anxiety on the one hand or overconfidence on the other , ” she says .
More tests alone will not @ @ @ @ @ @ @ must be able to safely isolate , and they must be given the resources to do so , says Stefan Baral , an infectious disease epidemiologist at Johns Hopkins Bloomberg School of Public Health .
“ If we want people to not go to work when they ’ re sick , we need to provide paid leave , ” he says .
“ If we want to prevent them from infecting their household , we need to provide them a place to isolate.
” One way to do this it to let infected @ @ @ @ @ @ @ are homeless stay in a hotel for a few weeks—as some states have already done .
Just as important , contact tracing should be done to stop single cases from becoming clusters or big flareups .
Currently there are not enough tracers working in the U.S. , but the Biden administration aims to hire more , as part of a Public Health Jobs Corps of at least 100,000 people .
Obtaining financing for this project , as well as funding more isolation facilities , would require legislation , however .
This—like other spending @ @ @ @ @ @ @ Senate .
Biden also needs to drastically increase the supply of PPE—such as face masks , face shields and gowns—to protect health care workers treating or caring for COVID patients .
To do this , the president-elect has said he will quickly use the Defense Production Act of 1950 , which President Trump invoked late and sparingly .
Biden could employ the act more aggressively , ensuring a more centralized PPE supply instead of having states compete with one another .
Even so , the act alone likely will not solve all the @ @ @ @ @ @ @ not just that manufacturers don ’ t make many masks—the materials come from overseas .
The whole supply chain is global , ” says Eric Toner , a senior scholar with the Johns Hopkins Center for Health Security at the university ’ s Bloomberg School of Public Health .
Building up supply chains in the U.S. will take a long time and be expensive .
“ There are no easy answers , ” Toner says .
Finally , even as he tries to quell the current pandemic , Biden needs to ensure the @ @ @ @ @ @ @ next one .
Restoring commitments to the World Health Organization ( Trump planned to leave it in July 2021 ) and giving more prominence to the National Security Council Directorate for Global Health Security and Biodefense ( which the Trump administration subsumed into other parts of the National Security Council ) are starts .
Biden also needs to relaunch the U.S. Agency for International Development ’ s PREDICT project , an effort to strengthen the world ’ s capability to detect pathogens with pandemic potential ; it ended in 2020 .
PREDICT was @ @ @ @ @ @ @ Health , ” an approach that focuses on connections among the health of people , animals and their shared environment .
“ The Biden administration has a real opportunity to bring a One Health approach to the pandemic , because it ’ s clearly not just about humans , ” Christine Kreuder Johnson , a professor of veterinary medicine at the University of California , Davis , who led the animal and human surveillance activities for PREDICT , told me .
Changes to the environment are forcing animals out of longstanding and remote @ @ @ @ @ @ @ , bringing with them viruses like the one that causes COVID .
And people , driven by population and economic pressure , are moving closer to wild animals .
Aggressive global surveillance for dangerous pathogens that live in these animals is the way to ensure that the catastrophes of 2020 do not repeat in coming years .
Read more about the coronavirus outbreak from Scientific American here .
And read coverage from our international network of magazines here .

As Joe Biden takes office, his most immediate priority is dealing with the catastrophe of COVID-19, which has killed hundreds of thousands of people in the U.S.—the highest toll of any country—and sickened and harmed millions. He is inheriting a dire situation from his predecessor, who resisted some of the most important measures to contain the new coronavirus, such as prompt testing and tracing and mask wearing, and who appeared unconcerned as a winter surge of infections devastated the country.
Biden and Kamala Harris, the new vice president, have outlined a COVID-19 plan to reverse this neglect. In addition to promoting more testing and mask wearing, the new administration wants to boost the production of personal protective equipment (PPE), provide economic support for small businesses, ensure a trustworthy vaccine rollout, and address racial and ethnic disparities in COVID's impact. Looking ahead, Biden's team has to get the country ready to handle the next pandemic better than it has dealt with this one.
Some of these goals are likely to face severe headwinds from Republicans in Congress and among millions who voted for Donald Trump. Both groups have fought against masks. Many opposed restrictions on business and personal activity. Congressional Republicans have signaled opposition to funding some of Biden's efforts—especially if, in early January, they retain their majority in the Senate after Georgia's runoff elections. So any amount of money Congress offers will probably be less than what Biden asks for.
One of Biden's responses has been to say he is “not going to shut down the economy—period. I am going to shut down the virus.” The incoming administration sees restrictions as a “dial” rather than an on-off switch. “That's a perfect metaphor,” says Monica Gandhi, an infectious disease physician at the University of California, San Francisco, School of Medicine. “It's triggering to use the word ‘lockdown.’” Biden aims to direct the U.S. Centers for Disease Control and Prevention to provide guidelines for ways to dial up or down restrictions on businesses, schools and gatherings. The evidence is clear that COVID transmission is higher at restaurants, bars and gyms but not so much at schools, so it makes sense to dial down restrictions on the last, Gandhi says.
There are also highly effective measures Biden can take that do not require congressional sign-off. Nearly every expert I spoke with agreed that one of the simplest and most important things Biden's team can do is encourage people to wear masks or face coverings. Despite extensive evidence supporting this measure's effectiveness, Trump made it a political statement not to wear one, mocking people—including Biden—for using them. Biden can try to change that. “President-elect Biden and Vice President–elect Harris have always modeled responsible behavior throughout the campaign,” Robert Rodriguez told me in November. He is an emergency physician at the U.C.S.F. School of Medicine and a member of the Biden-Harris administration's new coronavirus task force. “They're going to continue to promote the concept that wearing masks is noble—it's a civic duty that shows you care about the country and about others,” he said. Because masks have become so political, however, the messaging needs to strike a careful balance, Gandhi says. Like “lockdown,” the phrase “mask mandate” seems to really rile people up, she points out, “whereas ‘mask guidance’ doesn't.” Biden plans to work with governors and mayors to implement state and local mask rules and has asked Americans to wear masks for his first 100 days in office. And he does intend to make masks mandatory in federal buildings and on interstate public transportation.
A second key step will be to overcome some people's reluctance to get a coronavirus vaccine when shots become widely available later in 2021. Refusals will prolong the outbreak. According to a Pew survey in November, 42 percent of Black Americans said they would get a shot, slightly up from 32 percent in September. Much of this resistance stems from a history of racism and mistreatment of Black people in medicine. “We can't do anything without first reconciling that history,” says Nneka Sederstrom, director of clinical ethics at Children's Minnesota. Biden and his officials need to admit there is legitimate reason for distrust, and they must work to earn that trust back. Saying “we're acknowledging that history of racism ourselves” is the most important thing the Biden-Harris administration can do, Sederstrom says.
To convince skeptical populations, the new president and his team also need to reach out to community leaders who have the trust of their constituents, Sederstrom adds. Rodriguez says that is already in the works; further, the Biden administration has said it plans to address the pandemic's unequal effects on people of color by establishing a separate task force on racial and ethnic disparities in COVID, headed by Harris.
Vaccine skepticism is also linked to political affiliation. Just 50 percent of Republicans or Republican-leaning respondents said they were likely to get vaccinated, compared with 69 percent of Democrats or Democrat supporters, according to the November Pew survey. To reach Republicans, Biden will need to get the help of conservative leaders as well.
Both vaccine acceptance and mask wearing depend on the new president's ability to restore trust in science. “One of the biggest reasons that trust has been lost is [the Trump administration] essentially not letting science and scientists direct the pandemic response efforts,” says Angela Rasmussen, a virologist and affiliate researcher at the Georgetown Center for Global Health Science and Security. Political meddling at health agencies and repeated announcements that undercut public health measures exacerbated the problem. The Biden team can start to reverse the damage by showing that it is following scientific advice and delivering it in a clear, consistent message, Rasmussen says. “Some of that trust will be earned back, but it's not going to happen overnight.”
Beyond winning back trust, Biden needs to scale up COVID testing. Until vaccines reach most Americans, the virus will continue to spread, and testing is the way to identify and contain outbreaks. Yet it is still hard for most people in the U.S. to get a test and receive results quickly. Biden is going to have to increase the number of places for individuals to procure a diagnostic molecular test (something he has promised to do in part by doubling the number of drive-through testing sites). A national pandemic testing board, akin to the War Production Board that President Franklin D. Roosevelt created during World War II, could marshal resources for this initiative, and Biden has said he plans to create one.
Another promising approach is to have companies produce millions of so-called rapid antigen tests. These work well when people are most infectious. They can be taken at a local testing site and yield results in less than 30 minutes. The U.S. Food and Drug Administration has issued emergency authorization for eight such tests as of this writing, but they are not widely available. Michael Mina, an epidemiologist at Harvard University's T. H. Chan School of Public Health, has been an avid proponent of producing tens of millions of them for at-home use. “We have still failed to recognize that it's frequency of testing, not sensitivity,” that matters, he says. “You could have the best test in the world, but if it's not available or it takes four days, it's not useful.” The Biden administration should work directly with companies to develop and produce more tests, Mina says, the way the government contracts with Lockheed Martin and Raytheon to manufacture airplanes and military equipment. The tests should then be made freely available to homes, schools and businesses.
More tests alone will not be enough. People who test positive must be able to safely isolate, and they must be given the resources to do so, says Stefan Baral, an infectious disease epidemiologist at the Johns Hopkins Bloomberg School of Public Health. “If we want people to not go to work when they're sick, we need to provide paid leave,” he says. “If we want to prevent them from infecting their household, we need to provide them a place to isolate.” One way to do that is to let infected people who live in crowded housing or who are homeless stay in a hotel for a few weeks. Some states have already taken this approach. Just as important, contact tracing should be used to stop single cases from becoming clusters or big flare-ups. Currently there are not enough tracers working in the U.S., but the Biden administration aims to hire more as part of a Public Health Jobs Corps of at least 100,000 people. Obtaining financing for this project, as well as for more isolation facilities, would require legislation, however. This effort—like other spending plans—could face an uphill battle in the Senate.
Biden also needs to drastically increase the availability of PPE—such as face masks, face shields and gowns—to protect health care workers. To do so, Biden has said he will quickly use the Defense Production Act of 1950, which Trump as president invoked late and sparingly. If Biden employs the act more aggressively and on companies all along the PPE supply chain, it could lead to the development of a more robust centralized stockpile.
And even as he tries to quell the current pandemic, Biden needs to ensure that the U.S. is better prepared for the next one. Restoring commitments to the World Health Organization (Trump planned to leave it in July 2021), as well as a stand-alone National Security Council directorate for global health security, is a good way to start.
Biden also needs to relaunch the U.S. Agency for International Development's PREDICT project to strengthen abilities to detect pathogens with pandemic potential; it ended in 2020. PREDICT was built on the concept of “One Health,” which focuses on connections among the health of people, animals and their shared environment.
“The Biden administration has a real opportunity to bring a One Health approach to the pandemic because it's clearly not just about humans,” says Christine Kreuder Johnson, one of PREDICT's leaders. A professor of epidemiology and ecosystem health at the University of California, Davis, School of Veterinary Medicine, Johnson notes that changes to the environment are forcing animals out of remote habitats and into closer contact with humans, and people, driven by population and economic pressure, are moving closer to wild animals. Aggressive global surveillance for dangerous pathogens that live in these animals is one way to prevent the catastrophes of 2020 from repeating in coming years.


scientificamerican--2020-12-08--Asteroid Dust from Hayabusa2 Could Solve a Mystery of Planet Creation

The toaster-sized capsule hit our atmosphere at 12 kilometers per second , enduring temperatures of 3,000 degrees Celsius during its fiery descent before deploying a parachute to slow its velocity .
It continued to fall until it finally reached terra firma in the Australian outback .
Within hours , awaiting teams of scientists located the capsule ’ s landing site with radar and rushed via helicopter to retrieve it .
On board were pieces of an asteroid , the biggest such haul in history , captured millions of kilometers from Earth and returned safely to our planet .
This event @ @ @ @ @ @ @ agency JAXA ’ s Hayabusa2 mission to the asteroid Ryugu , took place , in local time , on Sunday , December 6 , 2020 .
It marked only the second occasion ( the first being its predecessor , the Hayabusa1 mission in 2010 ) that pieces of an asteroid have been returned to Earth by a spacecraft .
With these samples , scientists will be hoping to answer many questions about the history of our solar system , and even our own planet .
How old are asteroids like Ryugu , for @ @ @ @ @ @ @ material do they contain ?
And could they have first brought the raw ingredients for life to Earth billions of years ago ?
While most groups of researchers grapple with these outsized questions , one more rarefied cadre will be preoccupied with another , deceptively smaller matter : whether or not Hayabusa2 ’ s samples from Ryugu contain an intriguing ingredient of nearly all known meteorites .
So far , no one has been able to explain this ingredient ’ s origins , yet the ramifications of doing so are tremendous .
It @ @ @ @ @ @ @ nebulous history of the solar system , but also never-before-seen details of the process by which our sun ’ s retinue of planets formed .
In our understanding of how Earth—any planet in the cosmos , in fact—came to be , there may be nothing as important as the mystery of the chondrule .
Chondrules , small seedlike rocks measuring up to just a few millimeters across , are thought to have formed some 4.5 billion years ago , shortly after the birth of our solar system .
From there , they became @ @ @ @ @ @ @ , which make up the majority of the roughly 64,000 meteorites that humans have discovered throughout recorded history .
“ Chondrules are everywhere , ” says Fred Ciesla , a planetary scientist from the University of Chicago .
Even so , scientists have been unable to agree on how they formed for almost two centuries .
Some think they were byproducts of the planet formation process ; others posit they were the seeds of planet formation itself .
Either way , the menu of chondrule formation scenarios is vast , ranging from lightning-fused @ @ @ @ @ @ @ giant gas-heating shock waves rippling through the primordial cloud of material that surrounded our newborn sun .
Understanding chondrule formation could , in other words , reveal our solar system ’ s earliest moments .
And now , with fresh or prospective results from missions like Hayabusa2 as well as other avenues of research , chondrule-obsessed scientists are on the cusp of answering the centuries-old question of where they—and perhaps we—came from .
“ They are stained glass windows to the earliest time period of the solar system , ” says Harold Connolly @ @ @ @ @ @ @ Rowan University in New Jersey .
“ They are witnesses to processes that operated in the early solar system .
The question is , what did they witness ?
” In 1802 , the British chemist Edward Howard was one of the first scientists to recognize chondrules as “ rounded globules ” in meteorites .
Their name , given later by the German mineralogist Gustav Rose and Austrian mineralogist Gustav Tschermak , originates from the Greek chóndros ( “ grains ” ) and the German kleine kugeln ( “ small balls ” ) @ @ @ @ @ @ @ Henry Sorby would characterize them in greater detail , describing chondrules as “ droplets of fiery rain , ” molten globules that condensed around the sun , although , then as now , the exact mechanism of their formation was unclear .
The broad outlines of our solar system ’ s formation are far less contentious , incrementally assembled via careful observation and modeling .
This creation story begins more than 4.5 billion years ago , when dust and gas from a giant molecular cloud gravitationally collapsed to create a protostar that would @ @ @ @ @ @ @ spinning disk of gas and dust .
Within this disk , a mix of gravity , aerodynamics and electrostatic force caused grains of dust to stick together , building larger and larger agglomerations—such as planetesimals , the kilometer-scale building blocks of planets—which ultimately formed the planets themselves within perhaps just a few million years .
These worlds gradually settled into familiar forms and orbits , giving rise to the solar system we know today .
The delicate intricacies of how we reached this point are where things get mysterious , however .
Chondrules @ @ @ @ @ @ @ , the leap from dust to planetesimals .
How do you get from microscopic motes to entire worlds thousands of kilometers across ?
Essentially rocks within rocks , chondrules appear as rounded flecks in chondritic meteorites .
Some are visible to the naked eye , whereas others can only be seen under a microscope .
They would have solidified in the cold expanse of space after their unknown formation process , beginning their lives as molten droplets before coalescing into chondrites .
It is difficult to overstate just how abundant chondrules are : @ @ @ @ @ @ @ to have survived the process of incorporation into planets , they are very common off-world , often constituting the bulk of material within chondrite meteorites .
Some chondrites are so chondrule-packed they look almost like a conglomeration of beads .
Made of minerals such as olivine and pyroxene , and sometimes glass , chondrules themselves come in a variety of shapes , sizes and compositions—often containing a glittering array of crystals .
Scientists can date their formation to a window of a few million years 4.567 billion years ago by measuring the abundance @ @ @ @ @ @ @ called aluminum-26 .
“ This is a short-lived nuclide that only exists in the early solar system , ” says Noriko Kita , an expert in meteorite aging from the University of Wisconsin-Madison .
That advanced vintage makes chondrules the second-oldest recognizable objects in our solar system , after calcium-aluminum-rich inclusions ( CAIs ) , specks of white in meteorites that are thought to have formed one to three million years earlier by condensing out of the gas that surrounded our young sun .
There are many classes of chondrites .
Ordinary chondrites @ @ @ @ @ @ @ of chondrules and account for more than nine out of every 10 chondrule-containing space rocks .
Carbonaceous chondrites , which account for about 4 percent of all chondrites , have a high abundance of carbon and are very similar in composition to the sun ’ s surface , suggesting they formed in the inner solar system .
A subgroup called CI chondrites have no visible chondrules , having likely been altered by water .
And CB chondrites hold a particularly unique accolade , being the only type of chondrite for which there is @ @ @ @ @ @ @ “ These are a group that we think formed during one giant impact , ” says Sara Russell , a planetary scientist from the Natural History Museum in London .
That pinned-down provenance makes them “ kind of magical.
” Because apart from this one anomaly , the exact formation process for chondrules and chondrites remains a mystery—but not for any lack of trying .
For decades scientists have devised and tested myriad different formation models , but a consensus has remained elusive .
“ It ’ s frustrating , but also it @ @ @ @ @ @ @ don ’ t know , ” says Russell .
“ They ’ re obviously telling us about some ubiquitous , superimportant process about how our solar system formed .
We just have to work out what that is.
” Figuring out the mystery , however , has not always been smooth sailing .
In 2000 , at the Lunar and Planetary Science Conference in Houston , a stunned audience watched as John Wood—one of the most revered scientists studying chondrules—appeared to admit defeat in understanding their origin .
Like many before him , @ @ @ @ @ @ @ he first laid eyes on them .
“ [ These ] little balls of stone were so charming and interesting and mysterious that I just got seduced by them , ” he says .
But he was frustrated at the lack of progress that had been made .
“ We still don ’ t understand what the meteorites are telling us , and sometimes I wonder if we ever will , ” he later wrote in a summary of his speech .
A few years later , facing a lack of funding , @ @ @ @ @ @ @ attentions to oil painting and spending time with his wife .
“ I quit science cold turkey , ” he says .
The speech was a shock to many .
“ He basically said he ’ d wasted his entire life working on chondrules , because it was an impossible problem to solve , ” says Conel Alexander , a cosmochemist from the Carnegie Institution for Science in Washington , D.C. “ That got a lot of people pretty upset.
” Larry Nittler , also a cosmochemist from Carnegie who was in the @ @ @ @ @ @ @ up ” to defend chondrule research .
“ I said , ‘ I ’ m still excited about these incredible rocks from space , ’ ” he recalls .
“ I don ’ t think I ’ ve gotten as much attention or praise for anything I ’ ve done in my career .
The whole room erupted in applause.
” Yet one could be forgiven for pessimistically siding with Wood .
After all , space scientists have managed to definitively solve a wealth of seemingly intractable mysteries—teasing apart the very first moments @ @ @ @ @ @ @ discovering worlds around other stars , observing gravitational waves and even capturing images of a black hole .
Against such magnificent achievements , the stubborn enigma of the lowly chondrule seems to shrink even smaller than its already niche status .
Today there are , the joke goes , as many theories about chondrule formation as there are chondrule scientists themselves—with the acerbic addendum that tomorrow there will inevitably be even more .
The problem of chondrules has from the start been intergenerational , inspiring one cohort after another to try their hand @ @ @ @ @ @ @ success .
The main problem is finding a model that can explain all the different , diverse properties of chondrules .
“ There are no models that tick all the boxes , ” says Alexander .
To make chondrules , dust must have been heated to temperatures of up to 2,000 degrees Celsius by some process in the early solar system , before rapidly cooling over just days or even hours .
This process , whatever it was , likely occurred throughout the solar system , in order to account for the large @ @ @ @ @ @ @ Earth .
And the chondrules must also have drifted for a time through the dusty environs around our young sun , to account for the telltale rims of accumulated dust that encase their centers .
Most chondrule scientists fall into one of two camps .
The first believes that chondrules were among the first solid objects to appear in the solar system , forming directly from the solar nebula—the cloud of dust and gas that surrounded our young sun .
This would make chondrules a key stepping-stone from miniscule dust to larger kilometer-sized @ @ @ @ @ @ @ chondrules were not among the first solids to form , but actually arose after planetesimals—perhaps even after the planets themselves—being instead a by-product of the planet-formation process rather than being actively part of it .
Within the first camp , one idea is that gravitational instabilities in the disk of dust and gas around our sun resulted in “ shock fronts ” that fused some of the dust into chondrules .
“ If you look at a picture of a galaxy you see spiral arms spiraling round , and the same thing would @ @ @ @ @ @ @ ” says Rhian Jones , a cosmochemist at the University of Manchester in the U.K. “ And you can produce shock fronts associated with those density differences between the clumpy arms and the gas.
” The more radical nebula lightning model , meanwhile , suggests friction between dust and gas particles around the sun sparked immense discharges of electricity that fused this dust into chondrules , although it ’ s not entirely clear how such lightning would be produced .
Other models in this camp include magnetohydrodynamics , where huge magnetic fields would @ @ @ @ @ @ @ hot spots tens or hundreds of thousands of kilometers across that melt dust grains to churn out chondrules .
In the other camp , which proposes chondrule formation was post-planetesimal , one of the more prominent models is called impact jetting .
Here , planetesimals would collide at high velocities , creating the necessary heat to produce chondrules .
“ It essentially squirts out some molten material that could break up into droplets , ” says Brandon Johnson , a planetary scientist from Purdue University in Indiana .
A variant of this , @ @ @ @ @ @ @ between molten objects at lower velocities , releasing droplets into space that solidified into chondrules .
The nebula shock model , meanwhile , posits that Mars-sized planetary embryos moving through the nebula could act like boats sailing through water , fusing dust into chondrules .
“ As it ’ s moving through the gas at supersonic speeds , it drives a bow shock , ” says Steven Desch , an astrophysicist from Arizona State University .
“ The chondrule precursors , this dust , is heated by entering this compressed hot gas and @ @ @ @ @ @ @ include radiative heating , a relatively new idea that suggests planetesimals flying low over molten bodies could have been roasted and then cooled to produce chondrules .
Rocks that underwent this natural “ heat treatment ” process would be sturdier , and more likely to survive the passage through Earth ’ s atmosphere , handily explaining why most of the meteorites we find are chondrites .
“ The meteorites got hardened , and Earth ’ s atmosphere is a filter that is weighted towards really dense and hard stuff , ” says astronomer @ @ @ @ @ @ @ , one of the researchers behind the idea .
Against this rising theoretical tide , some wilder notions have already been ruled out .
Events from outside the solar system such as gamma-ray bursts—enormously energetic explosions from sources such as merging neutron stars or black holes—were once considered a possibility , but now seem implausible owing to the great distances involved .
Even so , many models still remain , complicated by the fact that chondrules are not really predicted by planet formation at all .
“ We can build a story about @ @ @ @ @ @ @ formation , ” says Ciesla .
“ It ’ s obvious that there ’ s a piece of the story that we ’ re missing.
” Narrowing down which of the remaining theories is correct is hard , and arguments can get heated .
“ The best way to make friends and enemies in meteoritics is to publish another chondrule-forming model , ” says Connolly .
At stake is what role chondrules played in our solar system .
If they were among the first solids to form , then some inescapable process took @ @ @ @ @ @ @ explain how planet formation begins around most any star .
But if not , are they less vital to the process than once thought ?
“ I ’ m putting my money on collisions right now , ” says planetary scientist Eugene Chiang from the University of California , Berkeley .
“ And to be totally up front about it , that makes [ them ] a little less interesting .
Because if you ’ re interested in planet formation , it means the chondrules are not the most primitive objects .
They @ @ @ @ @ @ @ our ideas on chondrule formation come from modeling of the early solar system and performing experiments on Earth to replicate different formation methods .
Meteorite scientist Aimee Smith from the University of Manchester and her colleagues are one of several teams around the world that perform such experiments , mixing chemicals into a powder to resemble different types of known chondrule compositions .
Then they place the powder in a furnace and heat it to extremely high temperatures for anywhere from hours to days , before cooling it to mimic different formation models @ @ @ @ @ @ @ look similar to the natural chondrules that we ’ ve studied , then we have a better of idea of how they formed , ” Smith says .
Experiments like these are crucial for understanding chondrules in concert with modeling of the solar system .
“ The experiments are just defining the conditions for chondrules , ” says Jones , Smith ’ s supervisor .
“ But models are trying to come up with scenarios in which those conditions are satisfied.
” And in our solar system , such modeling is starting to @ @ @ @ @ @ @ moments .
Recent work on measurements of isotope ratios in meteorites suggest two different reservoirs of chondrites formed early on , one in the inner solar system and one in the outer solar system , where chondrules may have been produced separately .
These separate populations would have mixed together after Jupiter , having initially formed more than twice as close to the sun , migrated out to its present position , an idea called the grand tack hypothesis .
If true , this would suggest that the story of our solar system @ @ @ @ @ @ @ chondrules themselves , offering yet another reason to lavish them with careful attention .
Elsewhere , observations of other solar systems—in particular , protoplanetary disks of dust and gas around young stars—are yielding useful information about possible scenarios for chondrule creation .
In 2014 , astrophysicist Huan Meng from the University of Arizona and colleagues saw evidence for a potential protoplanetary smash-up around a star called NGC-2547 ID8 more than 1,000 light-years from Earth , in the form of a flash of infrared light .
While not definitively linked to the formation of @ @ @ @ @ @ @ that suitably energetic collisions to make them do seem to occur in young systems .
“ Before [ our ] paper , we didn ’ t have any direct hard evidence of any extrasolar planetary impacts , ” says Meng .
In the future , we should also be able to better probe the distribution of dust around young stars with higher resolution images , letting us possibly refine some models of chondrule formation .
“ With improvements in techniques and telescopes , now we can start to see the dust production around @ @ @ @ @ @ @ , a planetary scientist from the French National Center for Scientific Research .
“ Maybe in the near future we can see the formation [ process ] of chondrules.
” Such telescopes may include NASA ’ s much-delayed James Webb Space Telescope , scheduled to launch in October 2021 , which could provide some intriguing answers in the infrared .
If chondrules are among the first solids to form around stars , they could be crucial catalysts for subsequent planet formation , in particular the jump from dust-sized to kilometer-sized objects .
“ @ @ @ @ @ @ @ need multi-meter to kilometer size objects to actually form the rocky parent bodies of planets , ” says Connolly .
“ What happens in that gap becomes really important.
” And perhaps chondrules are even more essential ; one model of planet formation , pebble accretion , posits that larger bodies swept up pebblelike dust in order to grow into planets .
Could those pebbles in fact be chondrules ?
“ We don ’ t know if they ’ re the same , ” says André Izidoro , a planetary scientist from Rice @ @ @ @ @ @ @ likely require “ a big sample of an asteroid , ” he says .
And as it happens , we just got one .
Preliminary estimates suggest Hayabusa2 only managed to bring back about a gram of material from asteroid Ryugu , but according to JAXA ’ s sample analysis team lead Shogo Tachibana , that should be enough to see if chondrules are present .
He and his team will begin studying the samples in earnest next year , after they are transported from Australia back to Japan .
What they will @ @ @ @ @ @ @ “ We don ’ t know if chondrules in Ryugu are different from other types of chondrules in other chondrites , ” says Tachibana .
Ryugu appears to be similar to Earth ’ s carbonaceous chondrites , so most experts expect chondrules to be present in the samples , although none know whether they will resemble those already in collections or will be like nothing ever seen before .
It could be , however , that Hayabusa ’ s samples prove to be chondrule-free .
“ I think that would be shocking to @ @ @ @ @ @ @ , overturning any already precarious consensus .
“ If there were no chondrules , and it looked like there had never been chondrules in them , then maybe chondrule formation is not such a ubiquitous process , ” says Russell .
Early results from a lander called MASCOT , deployed by Hayabusa2 onto Ryugu in October 2018 , have already tantalized scientists .
Images from the lander showed many white markings on the surface , which may have been CAIs , but also could have been chondrules .
“ We were surprised that @ @ @ @ @ @ @ ] and that there were so many of them , ” says Ralf Jaumann , head of MASCOT ’ s science team at the German Aerospace Center , or DLR , Germany ’ s space agency .
Only chemical studies of the samples back on Earth will reveal the markings ’ nature with certainty .
If chondrules are present , and similar to existing chondrules we know of , scientists will be able to link these to a specific planetesimal—namely Ryugu—to pinpoint the location , time and perhaps even conditions in which they @ @ @ @ @ @ @ new types of chondrules are found in the samples , however , that could give us a fresh perspective on the larger problem of origins—and scientists like Connolly favor such a scenario .
“ I certainly hope there ’ s a few surprises and we find objects we didn ’ t expect , ” he says .
And even if chondrules are not present , it could simply suggest Ryugu has been altered by water in its past , erasing any evidence of its chondrules , as with CI chondrites found on Earth @ @ @ @ @ @ @ return mission with extraterrestrial gifts in store for chondrule scientists .
NASA ’ s ORISIS-REx spacecraft is scheduled to return to Earth in September 2023 with recently acquired samples of another asteroid , called Bennu , that are expected to be chondrule-rich .
“ It would be really disappointing if we didn ’ t find chondrules in the material , ” says Connolly , who is also part of the OSIRIS-Rex team .
“ I ’ m looking forward to finding chondrules that I know and chondrules that I don ’ t know.
@ @ @ @ @ @ @ expected to solve the issue of chondrule formation , but they offer vital insights into the broader chondrule problem , with a major question yet to be answered : Were chondrules , these tiny molten droplets that solidified in space , the seeds that led to the formation of planets like Earth ?
Or were they the by-products of a violent formation process as hunks of rock smashed together ?
“ Now more and more people are talking about a planetesimal source , ” says Myriam Telus , a planetary scientist from the @ @ @ @ @ @ @ “ I do think coupling of the modeling and meteorite observations will get us to the answer.
” For some , the solution will be anything but simple , and perhaps more than one theory is correct .
“ I do not think it is a single sentence answer , ” says planetary scientist Sarah Stewart from the University of California , Davis .
“ There were probably many droplets being made in different ways.
” Russell agrees .
“ My favorite theory is that everyone ’ s right , ” she says @ @ @ @ @ @ @ somewhere in the solar system .
There were shock waves , there were impacts , there were bow waves , there was lightning .
I think these things all happened , and they all formed chondrulelike objects.
” What is clear is that across two centuries , these little droplets of fire have equally bemused and amazed countless curious scientists , and continue to fascinate .
Despite the frustrating lack of certainty about their origins and significance , the desire to know their secrets is going nowhere .
“ If I had to @ @ @ @ @ @ @ would have made the same attempt , ” says Wood .
And to anyone following in his footsteps ?
“ I would wish them good luck , ” he says .

The toaster-sized capsule hit our atmosphere at 12 kilometers per second, enduring temperatures of 3,000 degrees Celsius during its fiery descent before deploying a parachute to slow its velocity. It continued to fall until it finally reached terra firma in the Australian outback. Within hours teams of scientists located the capsule's landing site with radar and rushed via helicopter to retrieve it. Onboard were pieces of an asteroid, the biggest such haul in history, captured millions of kilometers from Earth and returned safely to our planet.
This event, the climax of the Japanese space agency JAXA's Hayabusa2 mission to the asteroid Ryugu, took place, in local time, on Sunday, December 6, 2020. It marked only the second time (the first being its predecessor, the Hayabusa mission, which launched in 2003) that a spacecraft has carried pieces of an asteroid back to Earth. With these samples, scientists hope to answer difficult questions about the history of our solar system and our own planet. How old are asteroids like Ryugu? How much water and organic material do they contain? And could they have first brought the raw ingredients for life to Earth billions of years ago?
While most groups of Ryugu researchers grapple with these outsized questions, a more rarefied cadre will be preoccupied with another, deceptively smaller matter: whether or not Hayabusa2's samples contain an intriguing ingredient of nearly all known meteorites. So far no one has been able to explain this ingredient's origins, yet the ramifications of doing so are tremendous. It may reveal to us not just some nebulous history of the solar system but also never before seen details of the process by which our sun's retinue of planets formed. In our understanding of how Earth—any planet in the cosmos, in fact—came to be, there may be nothing as important as the mystery of the chondrule.
Chondrules are small, seedlike rocks measuring up to just a few millimeters across and are thought to have formed some 4.5 billion years ago, shortly after the birth of our solar system. From there they became embedded in larger rocks, called chondrites, which make up the majority of the roughly 60,000 meteorites that humans have discovered throughout recorded history.
“Chondrules are everywhere,” says Fred Ciesla, a planetary scientist at the University of Chicago. Even so, scientists have been unable to agree on how they formed for almost two centuries. Some think they were by-products of planet formation; others posit they were the seeds of planet formation itself. Either way, the menu of chondrule creation scenarios is vast, ranging from lightning-fused dust to colliding chunks of protoplanets to giant, gas-heating shock waves rippling through the primordial cloud of material that surrounded our newborn sun.
Understanding chondrule formation could, in other words, reveal our solar system's earliest moments. And now, with fresh or prospective results from missions such as Hayabusa2 as well as other avenues of research, chondrule-obsessed scientists are on the cusp of answering the long-standing question of where they—and perhaps we—came from. “They are stained-glass windows to the earliest time period of the solar system,” says Harold Connolly, a cosmochemist and chondrule expert at Rowan University. “They are witnesses to processes that operated in the early solar system. The question is, What did they witness?”
Droplets of Fire
In 1802 British chemist Edward Howard was one of the first scientists to recognize chondrules as “rounded globules” in meteorites. Their name, given later by German mineralogist Gustav Rose and Austrian mineralogist Gustav Tschermak, originates from the Greek chóndros (“grains”) and the German kleine kugeln (“small balls”). In 1877 British scientist Henry Sorby would characterize them in greater detail, describing chondrules as “droplets of fiery rain,” molten globules that condensed around the sun, although then, as now, no one knew exactly how they formed.
The broad outlines of our solar system's genesis are clearer. This creation story, which scientists have assembled through decades of observation and modeling, begins more than 4.5 billion years ago, when dust and gas from a giant molecular cloud gravitationally collapsed to create a protostar that would become our sun. This protosun was surrounded by a spinning disk of gas and dust. Within this disk, a mix of gravity, aerodynamics and electrostatic force caused grains of dust to stick together, forming larger and larger agglomerations—such as planetesimals, the kilometer-scale building blocks of planets—and within a few million years the planetesimals coalesced into planets. These worlds gradually settled into the familiar forms and orbits we know today. But if the outlines of this story are clear, the details remain mysterious. Chondrules appear in the opening chapters, somewhere amid the leap from dust to planetesimals. How do you get from microscopic motes to entire worlds thousands of kilometers across?
CHONDRULES make up most of the material in a slice of “Barratta,” a 203-kilogram ordinary chondrite that fell in New South Wales, Australia. Credit: Matteo Chinellato Alamy Stock Photo
Chondrules are essentially rocks within rocks. They appear as rounded flecks in chondritic meteorites. Some are visible to the naked eye, whereas others can be seen only under a microscope. It is difficult to overstate just how abundant chondrules are: Despite the fact that none are known to have survived the process of incorporation into planets, they are very common off-world, often constituting the bulk of material within chondrite meteorites. Some chondrites are so packed with chondrules they look almost like a conglomeration of beads.
Made of minerals such as olivine and pyroxene and sometimes glass, chondrules themselves come in a variety of shapes, sizes and compositions. They often contain a glittering array of crystals. Scientists can date their formation to a window of a few million years, circa 4.567 billion years ago, by measuring the abundance of aluminum 26, a short-lived radioactive isotope they contain. That chronology makes chondrules the second-oldest recognizable objects in our solar system, after calcium-aluminum-rich inclusions (CAIs), specks of white in meteorites that are thought to have formed one million to three million years earlier by condensing out of the gas that surrounded our young sun.
There are many classes of chondrites. Ordinary chondrites, for example, are full of chondrules and account for more than nine out of every 10 chondrule-containing space rocks. Carbonaceous chondrites, which account for about 4 percent of all chondrites, typically have a high abundance of carbon; the most carbon-rich ones are thought to have formed in the outer solar system. A subgroup called CI chondrites possesses only microscopic chondrules because larger ones were weathered away by liquid water that once flowed through the parent body. And CB chondrites hold the distinction of being the only type of chondrite for which there is near-universal agreement on how they formed. “These are a group that we think formed during one giant impact,” says Sara Russell, a planetary scientist at the Natural History Museum in London. That pinned-down provenance makes them “kind of magical.”
As for the exact origins of all the other chondrite varieties? Those remain anyone's guess. “It's frustrating, but it's also kind of fun that we don't know,” Russell says. “They're obviously telling us about some ubiquitous, super important process about how our solar system formed. We just have to work out what that is.”
An Impossible Problem
In 2000, at the Lunar and Planetary Science Conference in Houston, a stunned audience watched as John A. Wood, then at Harvard University and one of the most revered scientists in meteoritics, appeared to admit defeat in understanding the origin of chondrules. Like many before him, Wood became fascinated by chondrules at first sight. “[These] little balls of stone were so charming and interesting and mysterious that I just got seduced by them,” he says. But he was frustrated at the lack of progress that had been made. “We still don't understand what the meteorites are telling us, and sometimes I wonder if we ever will,” he wrote in a summary of his speech. A few years later, facing a lack of funding, he opted to retire, turning his attentions to oil painting and spending time with his wife. “I quit science cold turkey,” Wood says.
The speech was a shock to many. “He basically said he'd wasted his entire life working on chondrules because it was an impossible problem to solve,” says Conel Alexander, a cosmochemist at the Carnegie Institution for Science in Washington, D.C. “That got a lot of people pretty upset.” Larry Nittler, also a cosmochemist at Carnegie, who was in the audience, says he “actually stood up” to defend chondrule research. “I said, ‘I'm still excited about these incredible rocks from space,’” he recalls. “I don't think I've gotten as much attention or praise for anything I've done in my career. The whole room erupted in applause.”
Wood's pessimism is understandable. After all, space scientists have managed to definitively solve a wealth of seemingly intractable mysteries. They have teased apart the first moments of the universe's existence, discovered worlds around other stars, observed gravitational waves and captured images of a black hole. Against such achievements, the stubborn enigma of the lowly chondrule seems to shrink even smaller than its already niche status. Today there are, the joke goes, as many theories about chondrule formation as there are chondrule scientists themselves—and tomorrow there will inevitably be more.
The problem of chondrules has from the start been intergenerational, inspiring one cohort after another to try tackling the issue, with varying success. The main problem is finding a model that can explain all the different, diverse properties of chondrules. “There are no models that tick all the boxes,” Alexander says. For chondrules to form, dust must have been heated to temperatures of up to 2,000 degrees C by some process in the early solar system, before rapidly cooling over just days or even hours. This process, whatever it was, most likely occurred throughout the solar system; that seems to be the only way to account for the large abundance of chondrules found in chondrites on Earth. The telltale rings of accumulated dust found in the centers of chondrules suggest that they must also have drifted for a time through the dusty environs around our newly coalescing sun.
Most chondrule scientists fall into one of two camps. The first believes chondrules were among the earliest solid objects to appear in the solar system, forming directly from the solar nebula—the cloud of dust and gas that surrounded our young sun. This would make chondrules a key stepping-stone from minuscule dust to larger kilometer-sized planetesimals. The second camp believes that chondrules were not among the first solids to form but actually arose after planetesimals—perhaps even after the planets themselves. They were, in this view, by-products of the planet formation process rather than an active part of it.
Within the first camp, one idea is that gravitational instabilities in the disk of dust and gas around our sun resulted in “shock fronts” that fused some of the dust into chondrules. “If you look at a picture of a galaxy, you see spiral arms spiraling round, and the same thing would have happened in the protoplanetary disk,” says Rhian Jones, a cosmochemist at the University of Manchester in England. “And you can produce shock fronts associated with those density differences between the clumpy arms and the gas.”
The more radical nebula-lightning model, meanwhile, proposes that friction between dust and gas particles around the sun sparked immense discharges of electricity that fused this dust into chondrules—although it is not clear how such lightning would be produced. Some models propose chondrule creation factories emerging from sheets of electric current trapped by huge magnetic fields within the spinning protoplanetary disk. Such “hotspots” could have been tens or hundreds of thousands of kilometers across and would have melted dust grains to churn out the primordial globules.
Artist’s impression of the Hayabusa2 spacecraft orbiting the asteroid Ryugu. Credit: Akihiro Ikeshita
In the other camp, whose members argue that chondrules formed after the planetesimals, one of the more prominent models is called impact jetting. Here planetesimals would collide at high velocities, creating the necessary heat to produce chondrules. “It essentially squirts out some molten material that could break up into droplets,” says Brandon Johnson, a planetary scientist at Purdue University. A variant of this, called splashing, would have involved collisions between molten objects at lower velocities, releasing droplets into space that solidified into chondrules.
The nebula-shock model, meanwhile, posits that Mars-sized planetary embryos moving through the nebula could act like boats sailing through water, fusing dust into chondrules. “As it's moving through the gas at supersonic speeds, it drives a bow shock,” says Steven Desch, an astrophysicist at Arizona State University. “The chondrule precursors, this dust, are heated by entering this compressed hot gas and are processed by it.”
Other ideas include radiative heating, a relatively new inclusion in some models that suggests planetesimals flying low over molten bodies could have been roasted and then cooled to produce chondrules. Rocks that underwent this natural “heat treatment” would be sturdier and more likely to survive the passage through Earth's atmosphere, which would explain why most of the meteorites we find are chondrites. “The meteorites got hardened, and Earth's atmosphere is a filter that is weighted toward really dense and hard stuff,” says astronomer William Herbst of Wesleyan University, one of the researchers behind the idea.
Against this rising theoretical tide, some wilder notions have already been ruled out. Events from outside the solar system such as gamma-ray bursts—enormously energetic explosions from sources such as merging neutron stars or black holes—were once considered a possibility but now seem implausible because of the great distances involved. Even so, many models still remain, complicated by the fact that chondrules are not really predicted by planet formation at all. “We can build a story about how planets form without ever invoking chondrule formation,” Ciesla says. “It's obvious that there's a piece of the story that we're missing.”
Narrowing down which of the remaining theories is correct is hard, and arguments can get heated. “The best way to make friends and enemies in meteoritics is to publish another chondrule-forming model,” Connolly says. At stake is what role chondrules played in our solar system. If they were among the first solids to form, then some inescapable process took place around our young sun that could explain how planet formation begins around most any star. But if not, are they less vital to the process than once thought?
“I'm putting my money on collisions right now,” says planetary scientist Eugene Chiang of the University of California, Berkeley. “And to be totally up front about it, that makes [them] a little less interesting. Because if you're interested in planet formation, it means the chondrules are not the most primitive objects. They're secondary products.”
Cooking up Chondrules
Most of our ideas on chondrule formation come from modeling the early solar system and performing experiments on Earth to replicate different formation methods. Meteorite scientist Aimee Smith of the University of Manchester and her colleagues are one of several teams around the world that perform such experiments, mixing chemicals into a powder to resemble different types of known chondrule compositions. Then they place the powder in a furnace and heat it to extremely high temperatures for anywhere from hours to days, before cooling it to mimic different formation models. “If we get ones that look similar to the natural chondrules that we've studied, then we have a better idea of how they formed,” Smith says.
Experiments such as these are designed to work in concert with solar system modeling. “The experiments are just defining the conditions for chondrules,” says Jones, Smith's collaborator. “But models are trying to come up with scenarios in which those conditions are satisfied.” And in our solar system, such modeling is starting to paint a new picture of its earliest moments.
Recent work on measurements of isotope ratios in meteorites indicates that two different reservoirs of chondrites formed early on—one in the inner solar system and one in the outer solar system, where chondrules may have been produced separately. These separate populations would have mixed together after Jupiter, having initially formed more than twice as close to the sun, migrated out to its present position, an idea called the grand tack hypothesis. If true, this would suggest that the story of our solar system's turbulent history is stored within chondrules themselves, offering yet another reason to lavish them with careful attention.
Elsewhere, observations of other solar systems—in particular, protoplanetary disks of dust and gas around young stars—are yielding information about possible scenarios for chondrule creation. In 2014 astrophysicist Huan Meng, then a graduate student at the University of Arizona, and his colleagues reported a flash of infrared light around a star called NGC-2547 ID8 over 1,000 light-years from Earth—evidence for a potential protoplanetary smash-up. Though not definitively linked to the formation of chondrules, the observation at least showed that suitably energetic collisions to make them do seem to occur in young systems. “Before [our] paper, we didn't have any direct hard evidence of any extrasolar planetary impacts,” Meng says.
In the future, astronomers should also be able to probe the distribution of dust around young stars with higher-resolution images, which could make it possible to refine some models of chondrule formation. “With improvements in techniques and telescopes, now we can start to see the dust production around young stars,” says Yves Marrocchi, a planetary scientist at the French National Center for Scientific Research. “Maybe in the near future we can see the formation [process] of chondrules.” Such telescopes may include NASA's much delayed James Webb Space Telescope, scheduled to launch this October.
If chondrules are among the first solids to form around stars, they may be crucial catalysts for subsequent planet formation, in particular the jump from dust-sized to kilometer-sized objects. “There's a gap when you need multimeter- to kilometer-size objects to actually form the rocky parent bodies of planets,” Connolly says. “What happens in that gap becomes really important.” And perhaps chondrules are even more essential; one model of planet formation, pebble accretion, posits that larger bodies swept up pebblelike dust to grow into planets. Could those pebbles in fact be chondrules? “We don't know if they're the same,” says André Izidoro, a planetary scientist at Rice University. Finding out would likely require “a big sample of an asteroid,” he says. And as it happens, we just got one.
“No Single-Sentence Answer”
Early assessments revealed that Hayabusa2 managed to bring back more than five grams of material from asteroid Ryugu. According to Shogo Tachibana, who leads JAXA's sample-analysis team, that should be more than enough to see if chondrules are present. He and his team began studying the samples early this year, after they were transported from Australia back to Japan. Most of their results are still forthcoming. “We don't know if chondrules in Ryugu are different from other types of chondrules in other chondrites,” Tachibana says. Ryugu appears to be similar to Earth's carbonaceous chondrites, so most experts expect chondrules to be present in the samples, but as of this writing, no one yet knows whether they will resemble those already in collections or will be like nothing ever seen before.
A member of the Hayabusa2 team holds the mission’s sample-return capsule shortly after its retrieval from a landing site in Woomera, southern Australia. Credit: JAXA via AP
It is possible that Hayabusa2's samples do not contain chondrules at all. “I think that would be shocking to the chondrule community,” Herbst says. “If there were no chondrules, and it looked like there had never been chondrules in them, then maybe chondrule formation is not such a ubiquitous process,” Russell says.
Early results from a lander called MASCOT, deployed by Hayabusa2 onto Ryugu in October 2018, have already tantalized scientists. Images from the lander showed many white markings on the surface, which may have been CAIs but also could have been chondrules. “We were surprised that we really could see [the markings] and that there were so many of them,” says Ralf Jaumann, head of MASCOT's science team at the German Aerospace Center, or DLR, Germany's space agency. Only chemical studies of the samples conducted back on Earth will reveal the nature of those markings.
If there are chondrules in the Hayabyusa2 samples and if they are similar to chondrules scientists have already studied, it will be possible to pinpoint the location, time and perhaps even conditions in which they formed. If the samples contain new types of chondrules, however, that could provide a fresh perspective on the larger problem of the origin of the solar system. Scientists such as Connolly would welcome such a scenario. “I certainly hope there are a few surprises and we find objects we didn't expect,” he says. And even if chondrules are not present, that could simply suggest that water made liquid from the heat released by radioactive decay, impacts and other sources had long ago erased evidence of its chondrules, similar to the origins of CI chondrites found on Earth.
Hayabusa2 is not the only sample-return mission with extraterrestrial gifts in store for chondrule scientists. NASA's OSIRIS-REx spacecraft is scheduled to return to Earth in September 2023 with recently acquired samples of another asteroid, called Bennu, that are expected to be chondrule-rich. “It would be really disappointing if we didn't find chondrules in the material,” says Connolly, who is also part of the OSIRIS-REx team. “I'm looking forward to finding chondrules that I know and chondrules that I don't know.”
If researchers ever manage to definitively determine how chondrules formed, that could go a long way toward revealing whether or not they were crucial to the subsequent creation of Earth and our sun's other small worlds. Presuming, of course, that the creation story ultimately revealed is relatively straightforward. Some experts, however, suspect no simple solutions will be found, in part because more than one theory is correct. “I do not think it is a single-sentence answer,” says planetary scientist Sarah Stewart of the University of California, Davis. “There were probably many droplets being made in different ways.” Russell agrees: “My favorite theory is that everyone's right. All these processes happened somewhere in the solar system. There were shock waves, there were impacts, there were bow waves, there was lightning. I think these things all happened, and they all formed chondrulelike objects.”
Which may mean Wood was on the right track all along when he made his infamous, career-capping declaration of futility: If nearly every idea for chondrule creation reflects a process that actually occurred in the solar system's ancient history, there may be no deeply meaningful distinctions among them. But that possibility won't keep new generations from trying, just as their predecessors did. “If I had to do it all over again, I would have made the same attempt,” Wood says. And to anyone following in his footsteps? “I would wish them good luck.”


scientificamerican--2020-12-08--The U.S. Risks Locking In a Climate Health Crisis in Response to COVID

As COVID-19 cases and hospitalizations hit record highs in the United States , and the threat of a double-dip economic recession looms , many are calling for continued and enhanced government stimulus .
While it is paramount that policy makers do all they can to address these urgent national interests , they must also take a long-term view .
How they decide to allocate economic recovery funds will have lasting consequences , with the potential to either amplify or eradicate another deadly agent that has been freely proliferating for centuries : fossil fuels .
The short-term symptoms resulting from the @ @ @ @ @ @ @ long manifested , with air pollution claiming millions of lives each year and plaguing millions more with diseases of the heart , lungs and brain in the U.S. and beyond .
In recent years , the longer-term symptoms have started to set in , with extreme weather events intensifying , food and water insecurity on the rise , and the first climate refugees , including Alaska ’ s coastal residents , being forced to abandon their homelands .
As with the differentiated impacts of the novel coronavirus , it is the most vulnerable @ @ @ @ @ @ @ our fossil fuel-driven society .
Although it may seem odd to draw parallels between the novel coronavirus and fossil fuels , as a climate and public health researcher , I have spent most of 2020 working on two reports that compel me to make this connection .
Published last week , the Lancet Countdown : Tracking Progress on Health and Climate Change U.S. Policy Brief and the Production Gap Report both share one urgent message to U.S. policymakers : do not allow COVID-19 recovery measures to lock us into another global health crisis @ @ @ @ @ @ @ effects of climate change are undeniable and worsening across the U.S. Over the past two decades , for example , heat-related mortality for older persons has almost doubled .
In 2019 , two billion hours of labor were lost because of extreme heat conditions in the service , manufacturing , agricultural and construction sectors .
Not to mention 14 climate-related disasters each causing over a billion dollars in damages .
“ Above-normal ” wildfire seasons in the western U.S. and hurricane seasons in the Atlantic are becoming the new norm .
While no @ @ @ @ @ @ @ risks , climate change is a threat multiplier that exacerbates existing health inequities and injustices .
As documented by one case study in the policy brief , the impacts of this year ’ s Hurricane Laura , one of the strongest hurricanes to ever hit Louisiana , were centered around the City of Lake Charles in Calcasieu Parish .
This region is predominantly populated by Black and low-income communities , which have been enduring some of the highest levels of air pollution in the country stemming from the hundreds of oil , gas @ @ @ @ @ @ @ coast .
Preliminary research suggests that long-term exposure to air pollution may be associated with increased COVID-19 mortality and morbidity rates .
Indeed , commensurate with national patterns , the rate of COVID-19 infections among Black people living in Calcasieu Parish is 1.7 times higher than that for white people .
In order to stay on track to limit global warming below 1.5 degrees Celsius and avoid worsening climate-related health impacts , the Production Gap Report shows that fossil fuel–producing nations need to collectively cut global production by 6 percent per year from @ @ @ @ @ @ @ existing energy plans foresee an average annual increase of 2 percent , which would lead to more than double the production consistent with the 1.5 degree C limit by 2030 .
As the world ’ s largest oil and gas producer , the U.S. is a key contributor to this global production gap .
And so far , despite widespread calls for a green recovery , the U.S. government has directed the majority of its energy-related recovery funds toward supporting fossil fuels : $ 72 billion compared to $ 27 billion for clean @ @ @ @ @ @ @ funds add to existing government assistance in the form of fossil fuel subsidies , rollbacks of more than 100 environmental regulations and refusal to strengthen air quality standards for another five years .
But the incoming administration offers us a glimmer of hope .
President-elect Biden has repeatedly committed to reentering the Paris Agreement “ on day one ” and put forward a plan for achieving “ a clean energy revolution and environmental justice.
” Vice President-elect Harris has proposed the “ first-ever global negotiation of the cooperative managed decline of fossil fuel @ @ @ @ @ @ @ Lancet Countdown outline ways to achieve these goals , including the elimination of fossil fuel subsidies and policy tools for leveraging decarbonization as an organizing theme for COVID-19 recovery efforts .
In the U.S. , the COVID-19 pandemic continues to demonstrate the brutal consequences that can occur when science is disregarded and responses are delayed or incommensurate with the scale and urgency of the problem—or absent altogether .
As the incoming administration seeks to address the current public health emergency , they must be sure to avoid worsening other health crises—air pollution and @ @ @ @ @ @ @ requires a managed , equitable and urgent transition away from fossil fuels .
The views and opinions expressed in this article are those of the author alone .

As COVID-19 cases and hospitalizations hit record highs in the United States, and the threat of a double-dip economic recession looms, many are calling for continued and enhanced government stimulus. While it is paramount that policy makers do all they can to address these urgent national interests, they must also take a long-term view. How they decide to allocate economic recovery funds will have lasting consequences, with the potential to either amplify or eradicate another deadly agent that has been freely proliferating for centuries: fossil fuels.
The short-term symptoms resulting from the extraction and burning of fossil fuels have long manifested, with air pollution claiming millions of lives each year and plaguing millions more with diseases of the heart, lungs and brain in the U.S. and beyond. In recent years, the longer-term symptoms have started to set in, with extreme weather events intensifying, food and water insecurity on the rise, and the first climate refugees, including Alaska’s coastal residents, being forced to abandon their homelands. As with the differentiated impacts of the novel coronavirus, it is the most vulnerable and marginalized who bear the brunt of our fossil fuel-driven society.
Although it may seem odd to draw parallels between the novel coronavirus and fossil fuels, as a climate and public health researcher, I have spent most of 2020 working on two reports that compel me to make this connection. Published last week, the Lancet Countdown: Tracking Progress on Health and Climate Change U.S. Policy Brief and the Production Gap Report both share one urgent message to U.S. policymakers: do not allow COVID-19 recovery measures to lock us into another global health crisis.
The Lancet Countdown details how the effects of climate change are undeniable and worsening across the U.S. Over the past two decades, for example, heat-related mortality for older persons has almost doubled. In 2019, two billion hours of labor were lost because of extreme heat conditions in the service, manufacturing, agricultural and construction sectors. Not to mention 14 climate-related disasters each causing over a billion dollars in damages. “Above-normal” wildfire seasons in the western U.S. and hurricane seasons in the Atlantic are becoming the new norm.
While no one is immune to these accelerating health risks, climate change is a threat multiplier that exacerbates existing health inequities and injustices. As documented by one case study in the policy brief, the impacts of this year’s Hurricane Laura, one of the strongest hurricanes to ever hit Louisiana, were centered around the City of Lake Charles in Calcasieu Parish. This region is predominantly populated by Black and low-income communities, which have been enduring some of the highest levels of air pollution in the country stemming from the hundreds of oil, gas and chemical facilities situated along the Louisiana coast. Preliminary research suggests that long-term exposure to air pollution may be associated with increased COVID-19 mortality and morbidity rates. Indeed, commensurate with national patterns, the rate of COVID-19 infections among Black people living in Calcasieu Parish is 1.7 times higher than that for white people.
In order to stay on track to limit global warming below 1.5 degrees Celsius and avoid worsening climate-related health impacts, the Production Gap Report shows that fossil fuel–producing nations need to collectively cut global production by 6 percent per year from now to 2030. Instead, their existing energy plans foresee an average annual increase of 2 percent, which would lead to more than double the production consistent with the 1.5 degree C limit by 2030. As the world’s largest oil and gas producer, the U.S. is a key contributor to this global production gap.
And so far, despite widespread calls for a green recovery, the U.S. government has directed the majority of its energy-related recovery funds toward supporting fossil fuels: $72 billion compared to $27 billion for clean energy, as of November. These funds add to existing government assistance in the form of fossil fuel subsidies, rollbacks of more than 100 environmental regulations and refusal to strengthen air quality standards for another five years.
But the incoming administration offers us a glimmer of hope. President-elect Biden has repeatedly committed to reentering the Paris Agreement “on day one” and put forward a plan for achieving “a clean energy revolution and environmental justice.” Vice President-elect Harris has proposed the “first-ever global negotiation of the cooperative managed decline of fossil fuel production.” The Production Gap Report and Lancet Countdown outline ways to achieve these goals, including the elimination of fossil fuel subsidies and policy tools for leveraging decarbonization as an organizing theme for COVID-19 recovery efforts.
In the U.S., the COVID-19 pandemic continues to demonstrate the brutal consequences that can occur when science is disregarded and responses are delayed or incommensurate with the scale and urgency of the problem—or absent altogether. As the incoming administration seeks to address the current public health emergency, they must be sure to avoid worsening other health crises—air pollution and climate change—in the process. Doing so requires a managed, equitable and urgent transition away from fossil fuels.
The views and opinions expressed in this article are those of the author alone.