scientificamerican--2020-12-07--Hand Transplants Demonstrate the Nervous System's Amazing Adaptability

In February 1964 Roberto Gilbert Elizalde , a Mayo Clinic–trained surgeon in Guayaquil , Ecuador , found the ideal candidate @ @ @ @ @ developed in his laboratory .
Julio Luna was a 28-year-old sailor who had lost his @ @ @ @ @ explosion .
Gilbert Elizalde , inspired by the successful transplantation of a kidney harvested from @ @ @ @ @ , intended to replace Luna 's missing appendage with a donor 's .

In February 1964 Roberto Gilbert Elizalde, a Mayo Clinic–trained surgeon in Guayaquil, Ecuador, found the ideal candidate for a radical procedure being developed in his laboratory. Julio Luna was a 28-year-old sailor who had lost his right hand in a grenade explosion. Gilbert Elizalde, inspired by the successful transplantation of a kidney harvested from a cadaver in the U.S., intended to replace Luna's missing appendage with a donor's.
For nine long hours Gilbert Elizalde and his team worked to prepare Luna's injured limb before skillfully marrying his bones, tendons, blood vessels, muscles, and skin with the forearm of a laborer who had died from a bleeding stomach ulcer. Using recently developed microsurgical techniques, the team stitched together the delicate, tubelike fascicles, nerve-surrounding sheaths that they hoped would guide sprouting sensory and motor nerves from Luna's injured forearm to reinnervate the new hand over the ensuing months.
Exhausted, the team watched nervously as the surgical clamps were released, and Luna's blood perfused his pale new hand to life. Long-distance congratulatory calls circulated. The news made the New York Times: “Dead Man's Hand Is Transplanted.” The hand became one of the first human body parts to be transplanted, after the kidney and cornea. It was a long shot. “Several specialists who were questioned yesterday agreed that the odds against ultimate success were huge,” the Times reported.
For the first week it looked like the skeptics might be proved wrong. When Luna contracted his forearm muscles, tendons in the new hand curled the fingers. Doctors gave Luna an early immunosuppressant, azathioprine, to stop his body from rejecting the foreign appendage. But in the second week it became clear that the immunosuppressant was not enough. When evidence of gangrene appeared, Luna was flown to Boston, where last-ditch efforts to save the hand failed. Twenty-three days after the transplant he became an amputee again.
The medical community both praised and condemned Gilbert Elizalde for this risky surgery. Critics called the procedure unethical, dangerous and unnecessary because it was not needed to save Luna's life—a position on hand transplantation that some experts still hold today. It took another three decades before hand transplantation received a second look.
Over those years surgical techniques evolved, and the development of more effective immunosuppressants (cyclosporine, followed by rapamycin and tacrolimus) allowed transplantation of certain solid organs—kidneys, livers, hearts—to become nearly routine. By the 1990s the success of these powerful pharmacological agents raised hopes of preventing rejection of transplants consisting of multiple tissue types—muscle, skin, bone, nerve and vascular tissue. The field of composite tissue allotransplantation was born. In 1998 a team in France performed the second hand transplant in history, followed shortly thereafter by a group at Louisville's Jewish Hospital in Kentucky. That recipient, Matthew Scott, will soon celebrate the 22nd anniversary of his successful transplant.
Yet hand transplantation remains experimental and, in some circles, controversial. The procedure has been performed only 100 or so times worldwide. Unlike other organ transplants, hand transplantation does not save lives. Recipients undergo a major operation followed by a lengthy recovery and intensive rehabilitation. They face a lifetime regimen of immunosuppressant drugs that can be hard on internal organs and that can increase the risks of certain cancers, infections and other illnesses. Twelve years after receiving his transplant David Savage, whom I will tell you more about soon, lost his life to a cancer that may have been related to immunosuppression.
So why not just use a prosthesis? When I asked transplant recipient Erik Hondusky this question, his answer was simple: “It is a two-handed world.” Hondusky's observation captures feelings expressed by other hand transplant recipients who also shared their dissatisfaction with prosthetics and the strong desire to feel whole again. Prostheses remain insensitive tools; you cannot use them to feel the glance of a spiderweb, or the little bumps marking “F” and “J” on a keyboard, or tiny temperature changes in a cup of coffee. Sadly, Erik developed a staph infection that led to the amputation of his hand nine years after his transplant. He uses a prosthesis reluctantly, only while riding his motorcycle.
Prosthetics come with their own challenges. Despite major advances in technology, a high percentage of amputees choose to give up their upper-extremity prostheses. Our longtime collaborator in Louisville, Christina Kaufman, notes that overall the record of surgical outcomes for hand transplants—and prevention of their rejection—remains impressive, with approximately 80 percent of recipients retaining the hand for at least five years. As techniques for matching immunologically compatible donors and recipients improve, this percentage is expected to grow, along with the number of recipients. Consequently, a successful transplant is no longer simply one that survives rejection. Instead success is increasingly defined based on the extent to which recipients develop functional use of their new hands. And that is where brain science comes into play.
Amputation and the Brain
My curiosity about how the brain controls the hands began early, inspired by watching my mother struggle with everyday tasks as a result of her multiple sclerosis, a disease in which one's own immune system ravages the fatty myelin that surrounds neurons in the brain and spinal cord. Her loss of hand function, balance, muscle weakness and spasticity linger as vivid memories and have driven my quest to understand how the brain controls the hands. Our brains dedicate a vast amount of real estate to planning and controlling hand actions. For more than 20 years my lab has been exploring this territory. We investigate the neural mechanisms of hand movements with functional magnetic resonance imaging (fMRI), a technique that allows us to noninvasively assess brain function by tracking local fluctuations in blood flow and oxygenation levels that are coupled to local changes in neural activity.
On a practical level, here is how fMRI works: Imagine that you volunteer for a common (and painfully boring) fMRI experiment that involves alternating the tapping of your fingers interspersed with periods of rest. When moving the fingers on your right side, a population of specialized neurons in the hand region of your left motor cortex (each brain hemisphere controls movements and processes sensations of the opposite side of the body) produces descending impulses, called action potentials. These signals pass through the brain's subcortical structures and down the spinal cord before triggering peripheral motor nerves that cause the appropriate muscles of your right forearm and hand to contract. Specialized receptors in your skin, tendons and joints are stimulated by your finger movements and send feedback signals through peripheral sensory nerves to the spinal cord. There, ascending impulses are relayed via subcortical structures to a specific pool of neurons in the hand area of your left somatosensory cortex, which processes incoming sensory signals.
All of this activity consumes energy. Within fractions of a second tiny capillaries dilate and saturate more active areas of your brain with an excess of oxygen-rich blood (hemoglobin). Changes in local blood oxygen concentrations that accompany neural activity affect the fMRI's magnetic field. Without oxygen bound to it, hemoglobin is strongly attracted to a magnetic field in what is called a paramagnetic state, and oxygenated hemoglobin is weakly repelled (a diamagnetic state). These effects can be captured as a blood-oxygen-level-dependent signal tethered to neural activity. During the little finger-tapping experiment, the hand areas of your left motor and sensory cortices glow with activity on the scanner console.
FMRI can even detect this brain activity in some people whose hands have been amputated. Many amputees experience powerful illusory sensations of a “phantom limb,” the sensation that the amputated appendage is still present. If a researcher asks a person with an amputation to move their phantom fingers, fMRI detects increased activity in the former hand areas. These findings suggest that the brains of at least some amputees retain a representation of the amputated hand even after the physical one is gone—although the story is not quite that simple.
Decades of basic neuroscience research in animals show that the organization of the cerebral cortex changes profoundly when it is deprived of routine activity from a limb—the result of damage to the peripheral nerves. That is, maps of sensory and motor functions in the cortex depend on stimulation. At least in part, the same appears to be true for humans as well. When amputees perform a task with their remaining hand, they exhibit increased activity in sensory and motor cortical areas formerly devoted to the now missing hand. This involvement of the former hand areas occurs in addition to typical activity within those areas dedicated to the healthy hand. Similarly, some brain-imaging studies have shown that movements of the lips may also increase activity in the former hand areas of amputees.
This is where hand transplantation gets very interesting to a brain scientist. Does the mature human brain retain enough plasticity years or even decades after amputation in areas formerly devoted to the amputated hand to take on control of the transplanted hand? The answer to this question could have broad implications for understanding the potential for recovery of function following injuries to the body, spinal cord or even the brain itself.
Brain Recovery
I started exploring this issue when David Savage and his wife, Karen, traveled to my lab, then located at the University of Oregon, a mere four months after his hand transplant surgery at Jewish Hospital in Louisville. If ever there was a case to test the boundaries of post-transplant recovery, David's was it. As a young man, he lost his right hand in a shop accident, and before the transplant he had lived as an amputee for almost 35 years. While we talked, David unzipped the Velcro straps that held his removable splint in place and nonchalantly began opening and closing his new hand. When he saw the stunned look on my face, he cracked a smile, grasped my pen and wrote his name in my notebook. Immediately it became clear who was the professor and who was the student.
Credit: David Cheney
Before getting into David's exciting results, we need a short aside to discuss the workings of the peripheral nerves in your hand and arm. Unlike the brain or spinal cord, peripheral nerves are capable of regrowing when injured. They regrow quickly, too—at the astonishingly speedy rate of up to two millimeters per day. A skilled microsurgeon will prepare a patient for this regeneration by carefully segregating the fascicles that encompass the various nerve branches and then delicately suture them to matched fascicles in the donor hand. These fascicles surround vast numbers of microscopic axons—the slender projections growing from the cell bodies of individual neurons—much like conduits surrounding the bundles of multicolored phone wires you might see at a construction site. Once surgically joined, the fascicles guide sprouting motor axons toward hand muscles, where they form neuromuscular junctions. Similarly, axons that send sensory signals to the brain are steered toward the skin, tendons and joints. There sensory nerves produce specialized receptors sensitive to changes in pressure, vibration, and temperature. The process through which peripheral nerves grow back and rejoin the sensory network is called reinnervation.
But even a gifted microsurgeon has limited control over where individual peripheral nerve axons actually terminate in the donor hand. The upshot is that subsequent reinnervation errors present a challenge for recovery of hand function. In David's forearm, the regenerating sensory nerves had inched their way through the repaired fascicles. Along the way, some axons had veered off and innervated patches of skin on his new palm, forming numerous branches capped by tiny sensory receptors. We know this because at this early point in his recovery, David was able to detect and localize light touch along the base of his thumb even though the rest of his hand still lacked sensation. I could not help thinking about how remarkable that was. His brain was receiving input originating in peripheral nerves that had last carried sensory signals from a hand more than three decades ago. These impulses were arising from specialized receptors that had only recently set up camp in an entirely different hand.
Reinnervation error was an issue for David, but his brain still found ways to compensate. A sensory nerve in the forearm that once received input from a patch of skin located, say, on the base of his birth thumb might now carry signals arising from an entirely different location on his transplanted palm. Somehow, in a very short period, David's brain had, nonetheless, learned to interpret the new input it received correctly; if I probed his palm, he experienced the feeling as arising from there and not from his thumb. These perceptions were a few millimeters off but still remarkable considering that until recently David had no right hand for more than three decades. Exactly how the brain solves this puzzle remains unclear. Our working hypothesis is that through the repeated pairing of visual and tactile feedback—seeing and touching at the same time during hand use—brain mechanisms learn to correct for reinnervation error.
DEXTROUS MOVEMENT with Rickelman’s transplanted hand allows the effortless buttoning of his shirt. Credit: Lyndon French
As if having waited patiently all this time for the opportunity to again process signals arriving from the hand, the appropriate area of David's sensory cortex responded vigorously when I gently brushed his transplanted palm during an fMRI scan. That is not to say, however, that postamputation reorganization had been fully reversed. As with other amputees, brushing the palm of David's intact left hand also elicited responses in this same area, the right sensory cortex. But he never showed any uncertainty about whether these sensations were coming from his intact or transplanted hand.
David eventually succumbed to cancer, but a transplanted hand can last for decades without any apparent consequences. At more than 21 years postsurgery Matthew Scott—the first case performed in Louisville—has kept his transplanted hand longer than anyone else who has had this operation. He spent 13 years as an amputee after losing his dominant left hand in a fireworks accident that occurred in his 20s. Matt visited us in 2008, nine and a half years after his operation. Feeling had long ago emerged throughout his new hand, indicating that regenerating sensory nerves had completed their journey. He localized touch at all locations on his transplanted hand; on average, he was only a few millimeters less accurate than on his uninjured one. We created a computer-controlled system to stimulate the tips of his fingers during an fMRI session, which revealed distinct maps of each individual digit within the hand area of his sensory cortex.
Although I am tempted to conclude that the organization of Matt's sensory cortex had sprung back to its preamputation organization, this conjecture would be overreaching. We lack data on his brain prior to his amputation, and the fact is that we all have slight differences in the fine-grained organization of our brains, which result from genetics and differing life experiences. We can safely say that Matt's sensory cortex appears to contain a map of his transplanted hand that is within the range of natural variation that we observe in healthy adults. Still, even eight years' post-transplant Matt's brain showed lingering evidence of his amputation. Stimulating his intact right hand also increased activity within the former hand area. How then can his hand function be so good? Part of the answer may involve contributions from other brain regions, located upstream from the hand regions, that are not directly involved in sensing and motor functions.
Simple tasks such as finger tapping or passively experiencing touch are useful means to probe the organization of the motor and sensory cortices. Everyday life, however, requires the ability to grasp and manipulate objects. These more complex, goal-directed actions involve areas of the brain involved with higher-level processing, such as the parietal and premotor areas. These cortical regions use multisensory information about the properties of the object and the positioning of one's body to plan movements targeted to a specific goal, such as grasping a cup to take a drink.
Ken Valyear led a project in our lab that used motion capture and fMRI techniques to study the recovery of visually guided grasping in transplant recipient Donald Rickelman, who had lived as a left-hand amputee for 14 years after losing his hand in an industrial accident. We were particularly interested in the role of the anterior intraparietal cortex (aIPC)—a small region located just behind the sensory hand area that is involved in properly shaping the hand to conform to the perception of objects' shapes, orientations and sizes.
At both 26 and 41 months after receiving his transplant, Donnie, like the other transplant recipients we have studied, showed evidence of persistent reorganization in his motor and sensory hand areas. Not surprisingly, he also experienced impediments in some basic hand functions. Detailed analyses of his hand motions, captured at high resolution as he reached for and grasped objects, revealed substantial improvements in coordination over this same period. How was he compensating for his motor and sensory impairments? To find out, we built a special apparatus that allowed us to ask this question with fMRI. When Donnie grasped objects at 26 months post-transplant, his aIPC and premotor cortex showed weak levels of grasp-related activity relative to people with intact limbs. At 41 months patterns of grasp-related activity had increased within the aIPC and premotor cortex and more closely resembled those of control subjects. We speculate that his improved ability to reach and grasp with his transplanted hand over time may be linked to these higher-level regions picking up the slack for the lagging performance of his reorganized motor and sensory areas.
Donnie and Matt continue to improve their sensory and motor functions many years after receiving their transplants, suggesting that the learning-related changes in the brain may continue to contribute to recovery long after the peripheral nerves have fully regenerated. A major goal of our current work is establishing the relationship between such experience-dependent changes in the brain and use of the hands during real-life activities as measured using wireless wearable sensor technology. These devices allow us to observe at high resolution hand and prosthesis activity over numerous days as participants go about their ordinary lives.
If the superpower of the peripheral nerves is their ability to regenerate when injured, the brain's is its capacity to reconfigure itself in response to changes in stimulation. Both play complementary roles in recovery from bodily injuries. Though in its infancy, work with hand transplant recipients is already showing us that the human brain can respond to the reinstatement of stimulation even after many years of deprivation. These findings challenge fundamental notions about the limits of neuroplasticity in mature adults and may give hope to those struggling to overcome the effects of amputation and other devastating bodily injuries. It may indeed be possible to reinstate the grasping and touch that had been lost decades earlier.


scientificamerican--2020-12-07--How to Fix COVID Contact Tracing

How to Fix COVID Contact Tracing

As coronavirus cases reach new peaks , surpassing 200,000 cases a day in the United States , public health departments are overwhelmed .
Departments are racing to hire yet more contact tracers and some are even asking people to do their own contact tracing and notification .
Other states are just now pushing out big tech ’ s solution to the pandemic : mobile contact tracing apps .
Initially , the hope was that contact tracing apps would be a silver bullet for contact tracing .
Evidence shows this is not the case .
Many European countries have been using @ @ @ @ @ @ @ .
As a result , some public health departments are taking matters into their own hands , turning away from big tech and innovating their own technology solutions .
Early evidence suggests these solutions may work better both for public health and for the public .
Traditional contact tracing works by interviewing those infected with COVID-19 about whom they have encountered during the prior two weeks .
The contact tracers then contact those who have been exposed to notify them of exposure .
But the relationship does not end there .
Contact tracers @ @ @ @ @ @ @ monitor their symptoms , for example , by taking their temperature twice per day .
They call back frequently to collect symptom data and ensure that those who become ill get appropriate care and avoid infecting others .
Contact tracers seek to build trust with those they are in contact with , to encourage truthful and accurate reporting from those they contact .
Before the pandemic hit , the U.S. employed about 2,200 contact tracers .
The American Medical Association estimates that more than 100,000 contact tracers are needed to address the pandemic @ @ @ @ @ @ @ this gap by automating the contact tracing process .
The apps track when app users encounter each other .
If a user later uploads a positive coronavirus test result , app users who ’ ve been exposed can be notified , all through the app .
But , contact tracing apps have struggled with low adoption rates , issues with the accuracy of the Bluetooth technology on which the apps rely to detect when app users come into contact with each other , and ensuring that app users remember to bring their phones @ @ @ @ @ @ @ test results .
These struggles have arisen , in part , because of how and why contact tracing apps were created .
Contact tracing apps were imagined and developed by technology companies with little input from public health experts or the public the apps are designed to serve .
When tech companies impose technologies in domains they do not understand , they often fail .
Consider the massive open online courses that technologists once dreamed would replace traditional degree programs or Google Health , intended to solve the issue of medical records sharing @ @ @ @ @ @ @ this new surge , some public health departments have started building their own solutions .
They are leveraging their experience with contact tracing and the technology they already have in order to scale contact tracing efforts .
For example , in Canada , Ottawa ’ s public health department automated contact tracing symptom checks and follow-ups by repurposing their existing OnBase case management software and online survey tools Ottawa contact tracers make first contact with at-risk individuals the traditional way : with a phone call from a trained contact tracer who can collect @ @ @ @ @ @ @ .
Follow-ups for symptoms , however , are done by sending a simple two-question survey via text message to those who have been exposed and added to the contact tracing database .
Public health data analysts can analyze symptom data to determine when a citizen needs additional phone-based or medical-care follow-ups .
In stark contrast to contact tracing apps that have at best achieved 35 percent adoption , over 91 percent of those who receive symptom-check text messages from Ottawa ’ s system complete their surveys .
At least 10 other public health @ @ @ @ @ @ @ system through partnering with ImageSoft , the tech company that powers Ottawa ’ s system .
This approach , blending technology with manual contact tracing , solves two key problems with contact tracing apps : trust and efficacy .
Trust is a key foundation of public health and a big problem for contact tracing apps ; my own research shows that people are divided on whom they trust to provide the apps as well as whether they trust the apps to actually work and to protect their data .
Beyond building trust , @ @ @ @ @ @ @ effective than apps .
Contact tracers attempt to reach all citizens who have been exposed repeatedly—at multiple times a day , multiple days a week—until they make contact .
In contrast , contact tracing apps rely heavily on people acting , unprompted .
For the apps to work , people need to voluntarily download the app , carry their phone with them when they leave the house , and upload their test results .
This full reliance on citizens to not just comply with contact tracing , but to participate actively , risks @ @ @ @ @ @ @ if only a minority of the population adopts these apps , let alone properly uses them .
If contact tracing apps continue to fall short on adoption as the surge of cases increases , now is perhaps the time for big tech to remember that they need to listen to the public health experts these apps attempt to replace , and the public that has failed to adopt this new technology .
Rather than relying on inferring people ’ s wants and needs from their data , tech companies need to engage those @ @ @ @ @ @ @ they do not have .
By partnering with public health departments and letting experts drive the innovation , tech companies can help keep contact tracers afloat rather than imposing solutions headed toward failure .

As coronavirus cases reach new peaks, surpassing 200,000 cases a day in the United States, public health departments are overwhelmed. Departments are racing to hire yet more contact tracers and some are even asking people to do their own contact tracing and notification. Other states are just now pushing out big tech’s solution to the pandemic: mobile contact tracing apps.
Initially, the hope was that contact tracing apps would be a silver bullet for contact tracing. Evidence shows this is not the case. Many European countries have been using these apps for months with limited success.
As a result, some public health departments are taking matters into their own hands, turning away from big tech and innovating their own technology solutions. Early evidence suggests these solutions may work better both for public health and for the public.
Traditional contact tracing works by interviewing those infected with COVID-19 about whom they have encountered during the prior two weeks. The contact tracers then contact those who have been exposed to notify them of exposure. But the relationship does not end there.
Contact tracers ask those who have been exposed to monitor their symptoms, for example, by taking their temperature twice per day. They call back frequently to collect symptom data and ensure that those who become ill get appropriate care and avoid infecting others. Contact tracers seek to build trust with those they are in contact with, to encourage truthful and accurate reporting from those they contact.
Before the pandemic hit, the U.S. employed about 2,200 contact tracers. The American Medical Association estimates that more than 100,000 contact tracers are needed to address the pandemic.
Contact tracing apps aim to fill this gap by automating the contact tracing process. The apps track when app users encounter each other. If a user later uploads a positive coronavirus test result, app users who’ve been exposed can be notified, all through the app.
But, contact tracing apps have struggled with low adoption rates, issues with the accuracy of the Bluetooth technology on which the apps rely to detect when app users come into contact with each other, and ensuring that app users remember to bring their phones with them and to upload their coronavirus test results.
These struggles have arisen, in part, because of how and why contact tracing apps were created. Contact tracing apps were imagined and developed by technology companies with little input from public health experts or the public the apps are designed to serve.
When tech companies impose technologies in domains they do not understand, they often fail. Consider the massive open online courses that technologists once dreamed would replace traditional degree programs or Google Health, intended to solve the issue of medical records sharing from the patient perspective.
Faced with this new surge, some public health departments have started building their own solutions. They are leveraging their experience with contact tracing and the technology they already have in order to scale contact tracing efforts.
For example, in Michigan, Ottawa County's public health department automated contact tracing symptom checks and follow-ups by repurposing their existing OnBase case management software and online survey tools
Ottawa contact tracers make first contact with at-risk individuals the traditional way: with a phone call from a trained contact tracer who can collect the necessary information and establish a relationship.
Follow-ups for symptoms, however, are done by sending a simple two-question survey via text message to those who have been exposed and added to the contact tracing database. Public health data analysts can analyze symptom data to determine when a citizen needs additional phone-based or medical-care follow-ups.
In stark contrast to contact tracing apps that have at best achieved 35 percent adoption, over 91 percent of those who receive symptom-check text messages from Ottawa’s system complete their surveys. At least 10 other public health departments have now adopted Ottawa’s system through partnering with ImageSoft, the tech company that powers Ottawa’s system.
This approach, blending technology with manual contact tracing, solves two key problems with contact tracing apps: trust and efficacy. Trust is a key foundation of public health and a big problem for contact tracing apps; my own research shows that people are divided on whom they trust to provide the apps as well as whether they trust the apps to actually work and to protect their data.
Beyond building trust, human contact tracers are also far more effective than apps.
Contact tracers attempt to reach all citizens who have been exposed repeatedly—at multiple times a day, multiple days a week—until they make contact. In contrast, contact tracing apps rely heavily on people acting, unprompted.
For the apps to work, people need to voluntarily download the app, carry their phone with them when they leave the house, and upload their test results. This full reliance on citizens to not just comply with contact tracing, but to participate actively, risks leaving significant gaps in protection, especially if only a minority of the population adopts these apps, let alone properly uses them.
If contact tracing apps continue to fall short on adoption as the surge of cases increases, now is perhaps the time for big tech to remember that they need to listen to the public health experts these apps attempt to replace, and the public that has failed to adopt this new technology.
Rather than relying on inferring people’s wants and needs from their data, tech companies need to engage those they serve directly and solicit the expertise they do not have. By partnering with public health departments and letting experts drive the innovation, tech companies can help keep contact tracers afloat rather than imposing solutions headed toward failure.


scientificamerican--2020-12-07--Fresh Data from Gaia Galaxy Survey Gives Best Map Ever of the Milky Way

Three weeks before Christmas , astronomers are opening one of their presents early .
Inside is a most welcome gift—a vast catalog of more than a billion stars in and around our galaxy , the most advanced of its kind ever made .
Already this new trove is being put to use , with eager astronomers poring through its data , hoping to unlock some of our galaxy ’ s most intriguing secrets in a way never before possible .
This gift comes from the European Space Agency ’ s ( ESA ) $ 1 billion Gaia telescope , launched @ @ @ @ @ @ @ measure the motions , positions and other key properties of billions of stars in and around our galaxy .
On Thursday , December 3 , ESA released a new batch of survey data—known as the Gaia Early Data Release 3 ( EDR3 ) —which contained updated information about a billion stars , including more refined calculations of their locations and velocities , vital tools for astronomers .
“ Distances to stars are about 30 percent more precise , and proper motions have increased by a factor of two , ” says Anthony Brown @ @ @ @ @ @ @ Netherlands , the lead on the Gaia data processing team .
“ That ’ s because we collected observations over 34 months , instead of 22 months for the previous release.
” Putting these refined calculations immediately to use were dozens of astronomers who gathered in a virtual “ hackathon , ” known as the Gaia Sprint , on Thursday .
With Gaia ’ s previous data release , in 2018 , these astronomers met in person in New York ; this year , owing to COVID-19 , a more remote meeting was @ @ @ @ @ @ @ Slack , combined with a digital conference room in the video-calling service Wonder , astronomers from around the world were able to mingle and discuss the data in real time as soon as it was publicly released .
“ We ’ re all [ working ] on the same data set on the same day , but we ’ re doing very different things , ” says Jackie Faherty from the American Museum of Natural History , one of the event ’ s organizers .
“ It ’ s like a party of @ @ @ @ @ @ @ Wyrzykowski from Warsaw University in Poland , who planned to use the data to look for signs of black holes as their gravitational pulls bent the light of more distant stars .
In particular , he was looking for small , so-called “ stellar mass ” black holes roughly five to 10 times the weight of our sun .
“ We only know of a few dozens of such black holes , ” he says .
“ So , we try to detect lensing effects .
If the light is disturbed by the @ @ @ @ @ @ @ then you see the effect of the black hole itself.
” Gaia provides a novel way to look for such effects on a huge scale .
“ Only Gaia can give us such precise measurements so that we can see the displacement of the background star ” from such lensing effects , Wyrzykowski says .
Chances are slim though , he notes ; only one or two such events are expected from the two billion stars in the Gaia data , if any at all .
Elsewhere , Ana Bonaca from Yale University @ @ @ @ @ @ @ were using EDR3 to hunt for clumps of dark matter in our galaxy .
Throughout the Milky Way can be found groups of stars appearing to move in an orderly queue , known as stellar streams .
Using Gaia ’ s precise data , it should be possible to map out the motion of these streams and look for any regions that appear to be unusually dense or bereft .
“ We noted these stars should all be traveling together , ” says Bonaca .
“ However , [ in ] a galaxy @ @ @ @ @ @ @ , the distribution [ should ] look kind of different.
” This should result in over- and under-densities in the stream , hinting at the gravitational influence of clumps of dark matter hidden from our view .
Already EDR3 was giving “ much cleaner views of the streams , ” says Price-Whelan , allowing possible clumps to be flagged more easily .
Kareem El-Badry from the University of California , Berkeley , meanwhile , was on the hunt for wide binaries—stars orbiting one another but separated by 10 to 100,000 times the Earth-sun @ @ @ @ @ @ @ contained numerous data processing errors that made more distant stars appear closer , El-Badry says , which made identifying wide binaries difficult .
But in EDR3 , “ so far it seems they ’ ve done a much better job of filtering out those bad sources , ” he says .
This should allow many more to be found , which could be useful for further calibrating Gaia ’ s data itself .
The telescope has a small amount of uncertainty in the stellar distances it calculates , up to 20 percent for @ @ @ @ @ @ @ cause problems for data analysis .
But El-Badry says seeing wide binaries could help resolve that issue if the distances to two stars known to be orbiting each other can be independently measured and compared .
Much has also been made of Gaia ’ s potential ability to spot exoplanets orbiting around some of these stars using a technique called astrometry , which can tease out the presence of planets by the way they can make their host stars wobble back and forth in the plane of the sky .
And while most @ @ @ @ @ @ @ until the telescope ’ s fourth release of data four or five years from now , the full Data Release 3 in early 2022 could contain information on previously discovered exoplanets .
“ In 2022 hopefully some of the known exoplanets will have astrometric measurements , which gives us some real information on the masses of these exoplanets , ” says Ronald Drimmel from the Turin Astrophysical Observatory and a Gaia team member .
“ We ’ re talking about the big exoplanets , the Jupiters going around other stars and seeing their @ @ @ @ @ @ @ small terrestrial exoplanets.
” Other research has also already been possible with EDR3 .
Drimmel has seen evidence for a previously hypothesized black hole in a stellar system , for example , thanks to the refinement of the Gaia data .
And astronomers were able to measure the acceleration of our solar system towards the galactic center by measuring the distances to quasars , bright objects billions of light-years away , arriving at a figure of seven kilometers per second per million years .
“ It ’ s a ridiculously small number , @ @ @ @ @ @ @ with Gaia , ” Brown says .
And over the coming weeks , months and years , much more exciting science awaits .
“ Gaia data is like a tsunami rolling through astrophysics , ” said Martin Barstow from the University of Leicester in the U.K. , part of the Gaia team , in a virtual press conference on Thursday announcing the data .
“ It ’ s just transformational .
Astronomy before and after Gaia will be unrecognizable .
”

Three weeks before Christmas, astronomers are opening one of their presents early. Inside is a most welcome gift—a vast catalogue of more than a billion stars in and around our galaxy, the most advanced of its kind ever made. Already this new trove is being put to use, with eager astronomers poring through its data, hoping to unlock some of our galaxy’s most intriguing secrets in a way never before possible.
This gift comes from the European Space Agency’s (ESA’s) $1-billion Gaia telescope, launched in 2013 on a decade-long mission to measure the motions, positions and other key properties of billions of stars in and around our galaxy. On Thursday, December 3, ESA released a new batch of survey data—known as the Gaia Early Data Release 3 (EDR3)—which contained updated information about a billion stars, including more refined calculations of their locations and velocities, vital tools for astronomers. “Distances to stars are about 30 percent more precise, and proper motions have increased by a factor of two,” says Anthony Brown of the University of Leiden in the Netherlands, who is lead of the Gaia data-processing team. “That’s because we collected observations over 34 months instead of 22 months for the previous release.”
Putting these refined calculations immediately to use were dozens of astronomers who gathered in a virtual “hackathon,” known as the Gaia Sprint, on Thursday. With Gaia’s previous data release in 2018, these astronomers met in person in New York City. This year, owing to COVID-19, a more remote meeting was required. Using the instant messaging platform Slack, combined with a digital conference room in the video-calling service Wonder, astronomers from around the world were able to mingle and discuss the data in real time as soon as they were publicly released. “We’re all [working] on the same data set on the same day, but we’re doing very different things,” says Jackie Faherty of the American Museum of Natural History, one of the event’s organizers. “It’s like a party of science.”
Among the participants was Łukasz Wyrzykowski of Warsaw University in Poland, who planned to use the data to look for signs of black holes as their gravitational pulls bent the light of more distant stars. In particular, he was looking for small, so-called stellar-mass black holes roughly five to 10 times the weight of our sun. “We only know of a few dozens of such black holes,” he says. “So we try to detect lensing effects. If the light is disturbed by the gravitational potential of the black hole, then you see the effect of the black hole itself.” Gaia provides a novel way to look for such effects on a huge scale. “Only Gaia can give us such precise measurements so that we can see the displacement of the background star” from such lensing effects, Wyrzykowski says. Chances are slim though, he notes. Only one or two such events are expected from the two billion stars in the Gaia data, if any at all.
Elsewhere, Ana Bonaca of Yale University and Adrian Price-Whelan of the Flatiron Institute were using EDR3 to hunt for clumps of dark matter in our galaxy. Throughout the Milky Way can be found groups of stars appearing to move in orderly queues known as stellar streams. Using Gaia’s precise data, it should be possible to map out the motion of these streams and look for any regions that appear to be unusually dense or bereft. “We noted these stars should all be traveling together,” Bonaca says. “However, [in] a galaxy with a lot of dark matter clumps, the distribution [should] look kind of different.” This should result in over- and under-densities in the stream, hinting at the gravitational influence of clumps of dark matter hidden from our view. Already EDR3 was giving “much cleaner views of the streams,” says Price-Whelan, allowing possible clumps to be flagged more easily.
Kareem El-Badry of the University of California, Berkeley, meanwhile, was on the hunt for wide binaries—stars orbiting one another but separated by 10 to 100,000 times the Earth-sun distance. Earlier releases of Gaia data contained numerous data processing errors that made more distant stars appear closer, El-Badry says, which made identifying wide binaries difficult. But in EDR3, “so far it seems they’ve done a much better job of filtering out those bad sources,” he says. This should allow many more to be found, which could be useful for further calibrating Gaia’s data itself. The telescope has a small amount of uncertainty in the stellar distances it calculates, up to 20 percent for the most distant stars, which can cause problems for data analysis. But El-Badry says seeing wide binaries could help resolve that issue if the distances to two stars known to be orbiting each other can be independently measured and compared.
Much has also been made of Gaia’s potential ability to spot exoplanets orbiting around some of these stars using a technique called astrometry, which can tease out the presence of planets by the way they can make their host stars wobble back and forth in the plane of the sky. And while most discoveries of new exoplanets are not expected until the telescope’s fourth release of data four or five years from now, the full Data Release 3 in early 2022 could contain information on previously discovered exoplanets. “In 2022 hopefully some of the known exoplanets will have astrometric measurements, which gives us some real information on the masses of these exoplanets,” says Ronald Drimmel of the Turin Astrophysical Observatory, who is a Gaia team member. “We’re talking about the big exoplanets, the Jupiters going around other stars and seeing their influence on their host star, not small terrestrial exoplanets.”
Other research has also already been possible with EDR3. Drimmel has seen evidence for a previously hypothesized black hole in a stellar system, for example, thanks to the refinement of the Gaia data. And astronomers were able to measure the acceleration of our solar system toward the galactic center by measuring the distances to quasars, bright objects billions of light-years away, arriving at a figure of seven kilometers per second per million years. “It’s a ridiculously small number, but we were able to measure it with Gaia,” Brown says. And over the coming weeks, months and years, much more exciting science awaits. “Gaia data is like a tsunami rolling through astrophysics,” said Martin Barstow of the University of Leicester in England, who is part of the Gaia team, in a virtual press conference announcing the data on Thursday. “It’s just transformational. Astronomy before and after Gaia will be unrecognizable.”


scientificamerican--2020-12-07--Undocumented Immigrants Are Half as Likely to Be Arrested for Violent Crimes as U.S.-Born Citizens

When Donald Trump announced that he was running for president , one of the first issues he raised in his speech was immigration—specifically , the idea that undocumented immigrants are dangerous .
“ They ’ re bringing drugs .
They ’ re bringing crime .
They ’ re rapists .
And some , I assume , are good people , ” he said .
As Trump ’ s presidency nears its end , his unwavering views on immigration are directly contradicted by a growing body of criminology research .
Studies overwhelmingly find no evidence that U.S. immigrants , including those @ @ @ @ @ @ @ than native-born Americans .
And now a study published in the Proceedings of the National Academy of Sciences USA that draws from a detailed and well-sourced data set comes to an even more dramatic conclusion .
It reports that between 2012 and 2018 , compared with their U.S.-born neighbors , undocumented immigrants in Texas were less than half as likely to be arrested for violent crimes or drug offenses and less than a quarter as likely to be arrested for property crimes .
“ Simply put , we found that undocumented immigrants have @ @ @ @ @ @ @ immigrants and , especially , native-born U.S. citizens , ” says study co-author Michael Light , a sociologist at the University of Wisconsin–Madison .
Charis E. Kubrin , a professor of criminology , law and society at the University of California , Irvine , who was not involved in the research , describes the paper as “ completely groundbreaking.
” It ’ s “ another nail in the coffin of what we know about the link between immigration and crime , ” she says .
Until now , scientists examining the relationship between @ @ @ @ @ @ @ issue broadly in part because many U.S. crime databases do not collect information on immigration status .
Research has demonstrated that areas with more immigrants experience no more crime than places with fewer of them and that immigration surges do not lead to increases in illegal activity .
The same has been shown to be true for undocumented immigrants in particular .
But as yet studies have not been able to link a specific immigration status to the rates for specific types of crimes .
The new paper is among the first to @ @ @ @ @ @ @ were able to delve into the details after learning that the Texas Department of Public Safety had begun cooperating with the Department of Homeland Security to check and record the immigration status of everyone arrested in the state .
He asked if the team could have access to the data , and the Texas officials did not object .
It was “ a eureka moment , ” Light says , because with these new data , he knew he and his colleagues could “ do some really interesting work.
” In addition to @ @ @ @ @ @ @ legal immigrants , as well as native-born Americans , Light and his team analyzed undocumented immigrants ’ relative contribution to felonies in Texas over the studied period .
They found that the proportion of arrests involving undocumented immigrants did not increase with time for certain offenses and even decreased for property , drug and traffic crimes .
Estimating the total population of undocumented immigrants in a particular area can be difficult , and Light concedes that the estimates his team used may not be perfect .
To account for potential errors , the @ @ @ @ @ @ @ would have to be to change their findings .
They found that the undocumented population in Texas would have to be less than half as large as they had estimated for violent crime rates among such immigrants to match those of U.S.-born Americans .
The calculation suggests that their findings are “ not due to nuances of data or estimation , ” says Bianca Bersani , a criminologist at the University of Maryland , who was not involved in the research .
The new study aligns with other research suggesting that immigration-reducing policies @ @ @ @ @ @ @ federal government introduced the Secure Communities program , which requires local law enforcement to work with federal immigration officials as a means to expel individuals “ who present the most significant threats to public safety , ” deportations increased , but crime did not drop .
Likewise Kubrin and her colleagues found that when California became a sanctuary state in 2017—limiting state and local police cooperation with federal immigration authorities—crime rates did not rise .
“ The reality is that immigration policy is not a solution to curb crime , ” she says @ @ @ @ @ @ @ the immigration issue .
The number of arrests made by U.S. Immigrations and Customs Enforcement ( ICE ) increased by 30 percent in fiscal year 2017—after Trump signed an executive order giving the agency more authority to detain undocumented immigrants .
And in fiscal year 2019 the number of people apprehended at the border between U.S. and Mexico increased to its highest level in 12 years , according to the Pew Research Center .
Researchers are not yet certain why undocumented immigrants are less crime-prone than documented ones or native-born Americans .
One @ @ @ @ @ @ @ emigrate from other countries to the U.S. are highly self-motivated and intrinsically less likely to commit crime .
It is also possible that immigrants fear deportation if they are caught , so they are more careful to follow laws .
American culture may also play a role .
“ The longer [ immigrants ] reside in the United States , the more they adapt to American society , and the more likely their arrest rates resemble those of the native-born , ” says Ramiro Martinez , Jr. , a quantitative criminologist at Northeastern @ @ @ @ @ @ @ of the issue remain , what is clear is that the new findings add to a robust body of literature suggesting that undocumented immigrants are not , in fact , criminals .
“ It ’ s rare in the social sciences to get such consistent findings , ” Kubrin says .
“ It ’ s really breathtaking .
”

When Donald Trump announced that he was running for president, one of the first issues he raised in his speech was immigration—specifically, the idea that undocumented immigrants are dangerous. “They’re bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people,” he said.
As Trump’s presidency nears its end, his unwavering views on immigration are directly contradicted by a growing body of criminology research. Studies overwhelmingly find no evidence that U.S. immigrants, including those who are undocumented, commit more crimes than native-born Americans. And now a study published in the Proceedings of the National Academy of Sciences USA that draws from a detailed and well-sourced data set comes to an even more dramatic conclusion. It reports that between 2012 and 2018, compared with their U.S.-born neighbors, undocumented immigrants in Texas were less than half as likely to be arrested for violent crimes or drug offenses and less than a quarter as likely to be arrested for property crimes.
“Simply put, we found that undocumented immigrants have lower felony arrest rates than both legal immigrants and, especially, native-born U.S. citizens,” says study co-author Michael Light, a sociologist at the University of Wisconsin–Madison.
Charis E. Kubrin, a professor of criminology, law and society at the University of California, Irvine, who was not involved in the research, describes the paper as “completely groundbreaking.” It’s “another nail in the coffin of what we know about the link between immigration and crime,” she says.
Until now, scientists examining the relationship between immigration and crime had to address the issue broadly in part because many U.S. crime databases do not collect information on immigration status. Research has demonstrated that areas with more immigrants experience no more crime than places with fewer of them and that immigration surges do not lead to increases in illegal activity. The same has been shown to be true for undocumented immigrants in particular.
But as yet studies have not been able to link a specific immigration status to the rates for specific types of crimes. The new paper is among the first to do so. Light and his team were able to delve into the details after learning that the Texas Department of Public Safety had begun cooperating with the Department of Homeland Security to check and record the immigration status of everyone arrested in the state. He asked if the team could have access to the data, and the Texas officials did not object. It was “a eureka moment,” Light says, because with these new data, he knew he and his colleagues could “do some really interesting work.”
In addition to calculating the crime rates of undocumented and legal immigrants, as well as native-born Americans, Light and his team analyzed undocumented immigrants’ relative contribution to felonies in Texas over the studied period. They found that the proportion of arrests involving undocumented immigrants did not increase with time for certain offenses and even decreased for property, drug and traffic crimes.
Estimating the total population of undocumented immigrants in a particular area can be difficult, and Light concedes that the estimates his team used may not be perfect. To account for potential errors, the researchers calculated how inaccurate their population estimates would have to be to change their findings. They found that the undocumented population in Texas would have to be less than half as large as they had estimated for violent crime rates among such immigrants to match those of U.S.-born Americans. The calculation suggests that their findings are “not due to nuances of data or estimation,” says Bianca Bersani, a criminologist at the University of Maryland, who was not involved in the research.
The new study aligns with other research suggesting that immigration-reducing policies do not prevent crime. After the federal government introduced the Secure Communities program, which requires local law enforcement to work with federal immigration officials as a means to expel individuals “who present the most significant threats to public safety,” deportations increased, but crime did not drop. Likewise Kubrin and her colleagues found that when California became a sanctuary state in 2017—limiting state and local police cooperation with federal immigration authorities—crime rates did not rise. “The reality is that immigration policy is not a solution to curb crime,” she says.
Yet Trump has poured resources into the immigration issue. The number of arrests made by U.S. Immigrations and Customs Enforcement (ICE) increased by 30 percent in fiscal year 2017—after Trump signed an executive order giving the agency more authority to detain undocumented immigrants. And in fiscal year 2019 the number of people apprehended at the border between U.S. and Mexico increased to its highest level in 12 years, according to the Pew Research Center.
Researchers are not yet certain why undocumented immigrants are less crime-prone than documented ones or native-born Americans. One contributing factor may be that individuals who emigrate from other countries to the U.S. are highly self-motivated and intrinsically less likely to commit crime. It is also possible that immigrants fear deportation if they are caught, so they are more careful to follow laws. American culture may also play a role. “The longer [immigrants] reside in the United States, the more they adapt to American society, and the more likely their arrest rates resemble those of the native-born,” says Ramiro Martinez, Jr., a quantitative criminologist at Northeastern University.
Although questions on many aspects of the issue remain, what is clear is that the new findings add to a robust body of literature suggesting that undocumented immigrants are not, in fact, criminals. “It’s rare in the social sciences to get such consistent findings,” Kubrin says. “It’s really breathtaking.”


scientificamerican--2020-12-07--Japanese Space Capsule Carrying Pristine Asteroid Samples Lands in Australia

For the second time ever , humanity has brought asteroid samples down to Earth .
A small capsule bearing pristine pieces of the near-Earth asteroid Ryugu touched down early this afternoon ( Dec. 5 ) within the remote and rugged Woomera Prohibited Area , about 310 miles ( 500 kilometers ) northwest of the South Australian capital of Adelaide .
The samples were snagged millions of miles from Earth by Japan ’ s Hayabusa2 mission , which studied the 3,000-foot-wide ( 900 meters ) Ryugu up close from June 2018 to November 2019 .
Hayabusa2 ’ s predecessor was the @ @ @ @ @ @ @ delivering pieces of the stony asteroid Itokawa in 2010 .
But the original Hayabusa ( Japanese for `` peregrine falcon '' ) returned less than 1 milligram of material .
Hayabusa2 ’ s bounty is expected to exceed 100 mg ( 0.0035 ounces ) , and its samples come from a very different kind of asteroid—a primitive `` C-type '' space rock rich in water and carbon-containing organic compounds .
`` The materials that formed the Earth , its oceans and life were present in the primordial cloud from which our solar system @ @ @ @ @ @ @ , these materials were in contact and able to chemically interact within the same parent objects , '' Japan Aerospace Exploration Agency ( JAXA ) officials wrote in an overview of Hayabusa2 .
`` These interactions are retained even today in primitive bodies ( C-type asteroids ) , so returning samples from these bodies for analysis will elucidate the origins and evolution of the solar system and the building blocks of life , '' they added .
Having the samples here on Earth is key ; scientists in well-equipped labs around the world @ @ @ @ @ @ @ greater detail than Hayabusa2 , or any other probe on its own in deep space , ever could .
The returned material ’ s purity is also a major selling point .
Researchers already have access to many meteorites , but these `` free samples '' of asteroids have been significantly altered by their trip through Earth ’ s atmosphere and their time on our planet ’ s surface .
The 1,340-lb .
( 690 kilograms ) Hayabusa2 spacecraft launched in December 2014 and rendezvoused with the rugged Ryugu on June 27 , @ @ @ @ @ @ @ campaign .
Hayabusa2 observed Ryugu in detail and also deployed multiple miniprobes onto the asteroid ’ s surface—several tiny , hopping rovers and a microwave-sized lander called MASCOT ( Mobile Asteroid Surface Scout ) , which was provided by the German Aerospace Center in collaboration with the French space agency CNES .
The main Hayabusa2 spacecraft made two trips of its own to Ryugu ’ s surface , both times to snag samples .
During the first of these operations , in February 2019 , Hayabusa2 scooped up some surface material .
In @ @ @ @ @ @ @ fired a 5.5-lb .
( 2.5 kg ) copper projectile at Ryugu , blasting a 33-foot-wide ( 10 m ) crater into the asteroid ’ s surface .
Then , that July , the probe swooped down and collected some of this recently excavated dirt and rock .
Hayabusa2 kept these two samples separate , so scientists will be able to compare material from two very different environments—Ryugu ’ s surface , which is weathered by space radiation , and the asteroid ’ s more protected depths .
With these samples secured , @ @ @ @ @ @ @ headed home .
On Nov. 26 of this year , when Hayabusa2 was about 2.2 million miles ( 3.6 million kilometers ) from Earth , the probe fired its engines in a key trajectory-refining burn .
The maneuver put Hayabusa2 on course toward a 6-mile-wide ( 10 km ) slice of sky over Woomera—the precision equivalent of targeting a ladybug from 0.6 miles ( 1 km ) away , JAXA officials wrote in a post-burn update .
Hayabusa2 released the 16-inch-wide ( 40 centimeters ) return capsule on Friday night ( Dec. 4 @ @ @ @ @ @ @ 137,000 miles ( 220,000 km ) from our planet , JAXA officials said .
The main spacecraft then conducted another engine burn to head away from Earth , for its work is not done : JAXA recently approved an extended mission for Hayabusa2 , which will fly by the small asteroid ( 98943 ) 2001 CC21 in 2026 and rendezvous with yet another space rock , 1998 KY26 , in 2031 .
But the return capsule , which has no propulsion system of its own , kept barreling toward Earth .
It hit @ @ @ @ @ @ @ 1728 GMT ) today , at an expected speed of roughly 26,840 mph ( 43,190 kph ) .
The little craft deployed its parachute a few minutes later , when it was about 6 miles ( 10 km ) above the ground , and touched down around 12:47 p.m. EST ( 1747 GMT ; 2:47 a.m. JST and 4:17 a.m. local Australian time on Dec. 6 ) , JAXA officials said .
Recovery crews headed out in a helicopter to search for the capsule , ultimately spotting it at 2:47 p.m. EST ( @ @ @ @ @ @ @ inspecting the craft , Hayabusa2 team members will transport it to JAXA ’ s Extraterrestrial Sample Curation Center in Japan .
This facility , which was completed in 2008 , was designed specifically to house and study cosmic material brought home by space missions .
Some of the Ryugu material will then make its way to labs around the world , where scientists will study it for clues about the solar system ’ s early days and the rise of life on Earth .
Several other spacecraft will soon follow Hayabusa2 ’ s @ @ @ @ @ @ @ heaven down to Earth .
China ’ s Chang ’ e 5 lunar lander , for example , scooped up pristine material from the moon ’ s surface this week .
This sample is scheduled to land in Inner Mongolia on Dec. 16 or Dec. 17 .
And in October of this year , NASA ’ s OSIRIS-REx spacecraft snagged a big sample of another carbon-rich near-Earth asteroid , the 1,640-foot-wide ( 500 m ) Bennu .
OSIRIS-REx ’ s return capsule will land in Utah in September 2023 , if all goes @ @ @ @ @ @ @ Hayabusa2 and OSIRIS-REx are broadly similar , and the two mission teams have been working together extensively over the past few years to help achieve them .
That collaboration will extend to the sharing of samples after touchdown , members of both teams have said .
In addition , the first stage of a complex , long-term campaign to haul Mars samples to Earth kicked off this past July with the launch of NASA ’ s Mars 2020 rover Perseverance , which will land on the Red Planet in February 2021 .
Among @ @ @ @ @ @ @ is the collection and caching of several dozen samples , which NASA and the European Space Agency will work together to bring home , potentially as early as 2031 .
JAXA is working on its own Mars sample-return project—a mission called Martian Moons Exploration ( MMX ) , which is scheduled to launch in 2024 .
MMX will grab samples of Phobos , one of the Red Planet ’ s two small moons , and bring them to Earth for analysis .
Copyright 2020 Space.com , a Future company .
All rights reserved @ @ @ @ @ @ @ , broadcast , rewritten or redistributed .

For the second time ever, humanity has brought asteroid samples down to Earth.
A small capsule bearing pristine pieces of the near-Earth asteroid Ryugu touched down early this afternoon (Dec. 5) within the remote and rugged Woomera Prohibited Area, about 310 miles (500 kilometers) northwest of the South Australian capital of Adelaide.
The samples were snagged millions of miles from Earth by Japan’s Hayabusa2 mission, which studied the 3,000-foot-wide (900 meters) Ryugu up close from June 2018 to November 2019.
Hayabusa2’s predecessor was the first to haul space-rock samples home, delivering pieces of the stony asteroid Itokawa in 2010. But the original Hayabusa (Japanese for "peregrine falcon") returned less than 1 milligram of material. Hayabusa2’s bounty is expected to exceed 100 mg (0.0035 ounces), and its samples come from a very different kind of asteroid—a primitive "C-type" space rock rich in water and carbon-containing organic compounds.
"The materials that formed the Earth, its oceans and life were present in the primordial cloud from which our solar system formed. In the early solar system, these materials were in contact and able to chemically interact within the same parent objects," Japan Aerospace Exploration Agency (JAXA) officials wrote in an overview of Hayabusa2.
"These interactions are retained even today in primitive bodies (C-type asteroids), so returning samples from these bodies for analysis will elucidate the origins and evolution of the solar system and the building blocks of life," they added.
Having the samples here on Earth is key; scientists in well-equipped labs around the world can scrutinize the cosmic rock in far greater detail than Hayabusa2, or any other probe on its own in deep space, ever could. The returned material’s purity is also a major selling point. Researchers already have access to many meteorites, but these "free samples" of asteroids have been significantly altered by their trip through Earth’s atmosphere and their time on our planet’s surface.
A long journey
The 1,340-lb. (690 kilograms) Hayabusa2 spacecraft launched in December 2014 and rendezvoused with the rugged Ryugu on June 27, 2018, kicking off an epic exploration campaign.
Hayabusa2 observed Ryugu in detail and also deployed multiple miniprobes onto the asteroid’s surface—several tiny, hopping rovers and a microwave-sized lander called MASCOT (Mobile Asteroid Surface Scout), which was provided by the German Aerospace Center in collaboration with the French space agency CNES.
The main Hayabusa2 spacecraft made two trips of its own to Ryugu’s surface, both times to snag samples. During the first of these operations, in February 2019, Hayabusa2 scooped up some surface material. In April of that year, the spacecraft fired a 5.5-lb. (2.5 kg) copper projectile at Ryugu, blasting a 33-foot-wide (10 m) crater into the asteroid’s surface. Then, that July, the probe swooped down and collected some of this recently excavated dirt and rock.
Hayabusa2 kept these two samples separate, so scientists will be able to compare material from two very different environments—Ryugu’s surface, which is weathered by space radiation, and the asteroid’s more protected depths.
With these samples secured, Hayabusa2 left Ryugu in November 2019 and headed home. On Nov. 26 of this year, when Hayabusa2 was about 2.2 million miles (3.6 million kilometers) from Earth, the probe fired its engines in a key trajectory-refining burn. The maneuver put Hayabusa2 on course toward a 6-mile-wide (10 km) slice of sky over Woomera—the precision equivalent of targeting a ladybug from 0.6 miles (1 km) away, JAXA officials wrote in a post-burn update.
Hayabusa2 released the 16-inch-wide (40 centimeters) return capsule on Friday night (Dec. 4), at a distance of about 137,000 miles (220,000 km) from our planet, JAXA officials said. The main spacecraft then conducted another engine burn to head away from Earth, for its work is not done: JAXA recently approved an extended mission for Hayabusa2, which will fly by the small asteroid (98943) 2001 CC21 in 2026 and rendezvous with yet another space rock, 1998 KY26, in 2031.
But the return capsule, which has no propulsion system of its own, kept barreling toward Earth. It hit the atmosphere at 12:28 p.m. EST (1728 GMT) today,at an expected speed of roughly 26,840 mph (43,190 kph). The little craft deployed its parachute a few minutes later, when it was about 6 miles (10 km) above the ground, and touched down around 12:47 p.m. EST (1747 GMT; 2:47 a.m. JST and 4:17 a.m. local Australian time on Dec. 6), JAXA officials said.
Recovery crews headed out in a helicopter to search for the capsule, ultimately spotting it at 2:47 p.m. EST (1947 GMT).
After securing and inspecting the craft, Hayabusa2 team members will transport it to JAXA’s Extraterrestrial Sample Curation Center in Japan. This facility, which was completed in 2008, was designed specifically to house and study cosmic material brought home by space missions.
Some of the Ryugu material will then make its way to labs around the world, where scientists will study it for clues about the solar system’s early days and the rise of life on Earth.
A golden age of sample-return missions
Several other spacecraft will soon follow Hayabusa2’s lead, bringing their own pieces of heaven down to Earth.
China’s Chang’e 5 lunar lander, for example, scooped up pristine material from the moon’s surface this week. This sample is scheduled to land in Inner Mongolia on Dec. 16 or Dec. 17. And in October of this year, NASA’s OSIRIS-REx spacecraft snagged a big sample of another carbon-rich near-Earth asteroid, the 1,640-foot-wide (500 m) Bennu. OSIRIS-REx’s return capsule will land in Utah in September 2023, if all goes according to plan.
The goals of Hayabusa2 and OSIRIS-REx are broadly similar, and the two mission teams have been working together extensively over the past few years to help achieve them. That collaboration will extend to the sharing of samples after touchdown, members of both teams have said.
In addition, the first stage of a complex, long-term campaign to haul Mars samples to Earth kicked off this past July with the launch of NASA’s Mars 2020 rover Perseverance, which will land on the Red Planet in February 2021. Among the life-hunting rover’s many tasks is the collection and caching of several dozen samples, which NASA and the European Space Agency will work together to bring home, potentially as early as 2031.
JAXA is working on its own Mars sample-return project—a mission called Martian Moons Exploration (MMX), which is scheduled to launch in 2024. MMX will grab samples of Phobos, one of the Red Planet’s two small moons, and bring them to Earth for analysis.
Copyright 2020 Space.com, a Future company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


scientificamerican--2020-12-07--Why Winter Wildfires May Get Worse

Why Winter Wildfires May Get Worse

A late-season flurry of flames is sweeping Southern California , driven by high-speed winds surging down the mountains toward the coast .
The Bond Fire , which ignited Thursday , has burned more than 7,000 acres and was 50 % contained as of last night .
Authorities warn that a combination of strong winds and warm , dry weather could increase the risk of more blazes this week .
Strong , dry winds are common in Southern California during the fall and winter months .
Known as Santa Ana winds , or Diablo winds in Northern California , they originate @ @ @ @ @ @ @ Great Basin region of the western United States .
High-pressure ridges in the atmosphere cause these air masses to sweep down through the mountains toward the coast , warming up and gathering speed as they go .
When paired with hot , dry weather conditions , they ’ re a major fire hazard .
The winds can fan small sparks into raging infernos .
Santa Ana winds occur throughout the fall and winter .
But the fire risk tends to be lower this late in the season , as the wet season sets @ @ @ @ @ @ @ time , we get a few good rainstorms , so the fuels are not flammable anymore , ” said Sasha Gershunov , a climate scientist at the Scripps Institution of Oceanography at the University of California , San Diego .
“ But this is a year that ’ s unusual.
” And it may happen more frequently as time goes on .
Climate change is drying out the climate in Southern California , scientists say .
That means less rain in the winter , leading to dry vegetation—fuel for wildfires—later in the season @ @ @ @ @ @ @ change may also affect the Santa Ana winds .
A study published last year suggests that warming may actually dampen Santa Ana wind activity—but the biggest effects will come earlier in the season .
That means these winds may be less frequent and less of a threat in the fall , pushing their biggest impact further into the winter .
When they do occur , though , they may be bigger fire hazards .
Other research has suggested that climate change may lead to warmer , drier Santa Ana winds in the coming @ @ @ @ @ @ @ of these two patterns—increased drying and changing winds—that creates the biggest cause for concern .
According to John Abatzoglou , a climate scientist and fire expert at the University of California , Merced , the most important question for California ’ s fire season is how often Santa Ana wind events will coincide with dry fuel .
That ’ s likely to happen more often in the future .
“ The contraction of the rainy season with climate change will ultimately allow winter rains to be held at bay a bit longer and @ @ @ @ @ @ @ heart of Santa Ana wind season , '' said Abatzoglou in an email to E & E News .
Back-to-back Santa Ana wind events—common in winter—may increase the risk of large , late-season fires as the region dries out , Gershunov added .
“ When a fire starts and it ’ s not put out when the second event and a third event starts , it just gets huge , ” he said .
The Thomas Fire was the biggest blaze in California history in December 2017 .
It ’ s still one @ @ @ @ @ @ @ Southern California .
“ That ’ s why I say it ’ s the poster for future Santa Ana wind fires , ” Gershunov added .
“ Late and huge.
” Reprinted from Climatewire with permission from E & E News .
E & E provides daily coverage of essential energy and environmental news at www.eenews.net .

A late-season flurry of flames is sweeping Southern California, driven by high-speed winds surging down the mountains toward the coast.
The Bond Fire, which ignited Thursday, has burned more than 7,000 acres and was 50% contained as of last night.
Authorities warn that a combination of strong winds and warm, dry weather could increase the risk of more blazes this week.
Strong, dry winds are common in Southern California during the fall and winter months. Known as Santa Ana winds, or Diablo winds in Northern California, they originate as masses of cool air in the Great Basin region of the western United States. High-pressure ridges in the atmosphere cause these air masses to sweep down through the mountains toward the coast, warming up and gathering speed as they go.
When paired with hot, dry weather conditions, they’re a major fire hazard. The winds can fan small sparks into raging infernos.
Santa Ana winds occur throughout the fall and winter. But the fire risk tends to be lower this late in the season, as the wet season sets in.
“Typically, by that time, we get a few good rainstorms, so the fuels are not flammable anymore,” said Sasha Gershunov, a climate scientist at the Scripps Institution of Oceanography at the University of California, San Diego. “But this is a year that’s unusual.”
And it may happen more frequently as time goes on.
Climate change is drying out the climate in Southern California, scientists say. That means less rain in the winter, leading to dry vegetation—fuel for wildfires—later in the season.
At the same time, climate change may also affect the Santa Ana winds.
A study published last year suggests that warming may actually dampen Santa Ana wind activity—but the biggest effects will come earlier in the season. That means these winds may be less frequent and less of a threat in the fall, pushing their biggest impact further into the winter.
When they do occur, though, they may be bigger fire hazards. Other research has suggested that climate change may lead to warmer, drier Santa Ana winds in the coming decades.
It’s the combination of these two patterns—increased drying and changing winds—that creates the biggest cause for concern. According to John Abatzoglou, a climate scientist and fire expert at the University of California, Merced, the most important question for California’s fire season is how often Santa Ana wind events will coincide with dry fuel.
That’s likely to happen more often in the future.
“The contraction of the rainy season with climate change will ultimately allow winter rains to be held at bay a bit longer and fuels to be drier deeper into the heart of Santa Ana wind season," said Abatzoglou in an email to E&E News.
Back-to-back Santa Ana wind events—common in winter—may increase the risk of large, late-season fires as the region dries out, Gershunov added.
“When a fire starts and it’s not put out when the second event and a third event starts, it just gets huge,” he said.
It’s already happened in recent years.
The Thomas Fire was the biggest blaze in California history in December 2017. It’s still one of the biggest ever to burn in Southern California.
“That’s why I say it’s the poster for future Santa Ana wind fires,” Gershunov added. “Late and huge.”
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--2020-12-07--Managing Emotional Polarization This Holiday Season

In an ordinary year , holiday angst is very real : Anxiety , depression and stress are all known to spike between Thanksgiving and the year ’ s end , as social engagements , travel and bills for holiday gifts simultaneously surge .
Yet 2020 has been far from ordinary , so we must expect that this holiday season will be unusual .
This year has been characterized by extremes .
Health care faced a crisis of epic and dangerous proportions , yet medical innovation is at an all-time high .
Financial markets experienced both staggering losses and colossal gains @ @ @ @ @ @ @ that even need to be explained ?
Along these lines , when it comes to our emotions this holiday season , we must expect emotional polarization : We will simultaneously feel better and worse than ever .
General holiday stress stands to be lower than in typical years since social expectations are diminished , and there is greater acceptance of human limitations and struggles .
No one will take it personally if our gifts or meals aren ’ t “ perfect ” this year , as long as we acknowledge our struggles .
@ @ @ @ @ @ @ to our performance and our appearances .
Perhaps for the first time in history , it is tolerable—even respectable—to be up-front with others when we are having a hard time .
Along these lines , pure introverts who are truly timid and shy are likely to breathe a sigh of relief this holiday season , as COVID-19 risks provide a socially acceptable reason to decline invitations to holiday parties and get-togethers .
This is serendipitous , since 2020 has been chock-full of social landmines such as discussions about the election , masking , @ @ @ @ @ @ @ fate of our economy ( in addition to “ the usual ” contentious conversation topics such as money and family ) .
The best reason to feel better than usual this holiday season is that 2020 is nearly over !
With the specter of the election behind us , and the very real potential for a vaccine around the bend , it ’ s hard not to feel hopeful and optimistic .
However , there are also unique challenges that lie ahead .
The biggest concern is potential angry exchanges over contentious issues @ @ @ @ @ @ @ sentiments about mask wearing , and issues related to racial inequality are just a few potentially explosive conversation topics when engaging with family , friends and co-workers .
For many people this year , discussing these issues turned Thanksgiving into Angstgiving .
Additionally , single extroverts who live alone are likely to find themselves in particularly challenging circumstances this holiday season .
Such individuals thrive on social engagement and are likely to feel deprived as holiday parties go socially distant or online this year .
Because of these trends , depression stands to @ @ @ @ @ @ @ the bend into 2021 , since social isolation is a key contributing factor to sadness and anhedonia .
The biggest concern ahead is that 2020 may not end well .
There remains so much that is unknown and uncertain about the electoral transition , the dramatic recent spike in COVID cases , the question of how quickly and fairly vaccines will be distributed , and the economy .
Many expect that 2021 will be choppy , at least out the gate , and there is certainly good reason for concern about such predictions @ @ @ @ @ @ @ of emotional polarization as the year to end all years finally winds to an end ?
First , we must simply recognize our vulnerability for emotional polarization .
When the human body experiences infection , high degrees of inflammation are coupled with frantic efforts of the immune system to quell the fires .
Similarly , when we experience extreme emotional states such as exhilaration and ecstasy , we become more likely to experience anguish and desperation .
In severe cases this can manifest as bipolar disorder , but in the majority of instances @ @ @ @ @ @ @ are very nothing to be concerned about , in of themselves .
Second , we must be wary that emotional polarization can give way to maladaptive behaviors , which can perpetuate distress and lead to impairment , or worse .
Left unchecked , the excitement about being done with 2020 can lead to elation and increase vulnerabilities to engage in risk-taking behaviors .
Conversely , antagonistic interactions with family and friends can ruin lifelong relationships ; recent data suggest that political differences are a significant factor in breakups and divorces .
Finally , @ @ @ @ @ @ @ limit emotional polarization , by slowing down and being mindfully aware of how we feel .
We may wish for this year to be over , but instead of rushing through the final weeks , we ’ ll be better off setting aside just a few minutes each day to calmly reflect on how we feel , and to take inventory of our actions over the previous 24 hours .
By attending to our emotions and slowing down our responses , we can reset the balance as we navigate through what will hopefully @ @ @ @ @ @ @ of history .

In an ordinary year, holiday angst is very real: Anxiety, depression and stress are all known to spike between Thanksgiving and the year’s end, as social engagements, travel and bills for holiday gifts simultaneously surge. Yet 2020 has been far from ordinary, so we must expect that this holiday season will be unusual.
This year has been characterized by extremes. Health care faced a crisis of epic and dangerous proportions, yet medical innovation is at an all-time high. Financial markets experienced both staggering losses and colossal gains. As for the election … does that even need to be explained? Along these lines, when it comes to our emotions this holiday season, we must expect emotional polarization: We will simultaneously feel better and worse than ever.
Let’s start with the good news.
General holiday stress stands to be lower than in typical years since social expectations are diminished, and there is greater acceptance of human limitations and struggles. No one will take it personally if our gifts or meals aren’t “perfect” this year, as long as we acknowledge our struggles. That creates less pressure when it comes to our performance and our appearances. Perhaps for the first time in history, it is tolerable—even respectable—to be up-front with others when we are having a hard time.
Along these lines, pure introverts who are truly timid and shy are likely to breathe a sigh of relief this holiday season, as COVID-19 risks provide a socially acceptable reason to decline invitations to holiday parties and get-togethers. This is serendipitous, since 2020 has been chock-full of social landmines such as discussions about the election, masking, diversity/inclusion, homeschooling, and the future fate of our economy (in addition to “the usual” contentious conversation topics such as money and family).
The best reason to feel better than usual this holiday season is that 2020 is nearly over! With the specter of the election behind us, and the very real potential for a vaccine around the bend, it’s hard not to feel hopeful and optimistic.
However, there are also unique challenges that lie ahead.
The biggest concern is potential angry exchanges over contentious issues of the day. Political polarization, sentiments about mask wearing, and issues related to racial inequality are just a few potentially explosive conversation topics when engaging with family, friends and co-workers. For many people this year, discussing these issues turned Thanksgiving into Angstgiving.
Additionally, single extroverts who live alone are likely to find themselves in particularly challenging circumstances this holiday season. Such individuals thrive on social engagement and are likely to feel deprived as holiday parties go socially distant or online this year. Because of these trends, depression stands to hit an all-time high as we round the bend into 2021, since social isolation is a key contributing factor to sadness and anhedonia.
The biggest concern ahead is that 2020 may not end well. There remains so much that is unknown and uncertain about the electoral transition, the dramatic recent spike in COVID cases, the question of how quickly and fairly vaccines will be distributed, and the economy. Many expect that 2021 will be choppy, at least out the gate, and there is certainly good reason for concern about such predictions.
How can we navigate the vicissitudes of emotional polarization as the year to end all years finally winds to an end?
First, we must simply recognize our vulnerability for emotional polarization. When the human body experiences infection, high degrees of inflammation are coupled with frantic efforts of the immune system to quell the fires. Similarly, when we experience extreme emotional states such as exhilaration and ecstasy, we become more likely to experience anguish and desperation. In severe cases this can manifest as bipolar disorder, but in the majority of instances, disparate and even conflictual emotional states are very nothing to be concerned about, in of themselves.
Second, we must be wary that emotional polarization can give way to maladaptive behaviors, which can perpetuate distress and lead to impairment, or worse. Left unchecked, the excitement about being done with 2020 can lead to elation and increase vulnerabilities to engage in risk-taking behaviors. Conversely, antagonistic interactions with family and friends can ruin lifelong relationships; recent data suggest that political differences are a significant factor in breakups and divorces.
Finally, we can gain some emotional equilibrium and limit emotional polarization, by slowing down and being mindfully aware of how we feel. We may wish for this year to be over, but instead of rushing through the final weeks, we’ll be better off setting aside just a few minutes each day to calmly reflect on how we feel, and to take inventory of our actions over the previous 24 hours. By attending to our emotions and slowing down our responses, we can reset the balance as we navigate through what will hopefully be the end of this tumultuous period of history.