Scientists release new view from OSIRIS-REx’s asteroid smash and grab

November 2, 2020 Stephen Clark

This view from the OSIRIS-REx spacecraft’s navigation camera shows asteroid Bennu as the probe moved in for a sample collection maneuver Oct. 20. 

Credit: NASA/Goddard/University of Arizona/Lockheed Martin

Scientists say the touch and go landing by NASA’s OSIRIS-REx spacecraft on an asteroid last month revealed fresh insights into the structure of loose rocks that may cover the surfaces of many small planetary bodies — material that is more akin to a playground ball pit than solid bedrock.

The structure of the asteroid’s outermost layer is evident in imagery captured by the OSIRIS-REx spacecraft as it swooped down to the airless world more than 200 million miles (330 million kilometers) from Earth on Oct. 20.

The next day, NASA released imagery from a narrow-angle camera aimed at the spacecraft’s 11-foot-long (3.4-meter) robotic arm. A dinner plate-sized sample collection device at the end of the arm fired a bottle of compressed nitrogen gas as the spacecraft contacted the surface of asteroid Bennu, a small planetary body measuring about one-third of a mile in diameter.

The discharge of nitrogen gas helped force asteroid specimens into the collection chamber. After six seconds on the asteroid’s surface, OSIRIS-REx fired thrusters to back away from Bennu.

Scientists later received close-up images of the sample collection head, showing it crammed with material scooped up from the asteroid’s surface. Some asteroid particles were visible escaping from the collection chamber, prompting managers to command the spacecraft to stow the sample head inside its Earth return capsule sooner than expected, minimizing the loss of specimens.

The sampling device was sealed inside the OSIRIS-REx spacecraft’s return capsule Oct. 28.

Late last week, officials released another series of images taken during the spacecraft’s touch and go landing. These were captured by a wide-angle navigation camera on OSIRIS-REx.

According to the OSIRIS-REx science team, the navigation camera — or NavCam — images were captured over a period of approximately three hours. The sequence begins around an hour after OSIRIS-REx performed an orbit departure maneuver to begin its descent, and ends about two minutes after the spacecraft’s back-away burn, officials said.

A slew, or rotation, maneuver is visible in the middle of the image sequence as OSIRIS-REx points its sampling arm toward target sampling site on asteroid Bennu, a region named “Nightingale.”

“As the spacecraft nears site Nightingale, the sampling arm’s shadow comes into view in the lower part of the frame. Shortly after, the sampling head impacts site Nightingale (just outside the camera’s field of view to the upper right) and fires a nitrogen gas bottle, which mobilizes a substantial amount of the sample site’s material,” the OSIRIS-REx team wrote in a description of the NavCam imagery.

“Several seconds later, the spacecraft performs a back-away burn and the sampling arm’s shadow is visible against the disturbed surface material. The team continues to investigate what caused the extremely dark areas visible in the upper and middle parts of the frame,” the team wrote. “The upper area could be the edge of the depression created by the sampling arm, a strong shadow cast by material lofted from the surface, or some combination of the two.

“Similarly, the middle dark region that first appears in the lower left of the image could be a depression caused by one of the spacecraft thrusters as it fired, a shadow caused by lofted material, or a combination of both.”

The Lockheed Martin-built OSIRIS-REx spacecraft relied on the black-and-white navigation camera images to autonomously guide itself to a safe touchdown zone on Bennu. Navigation algorithms compared the camera’s images to a map pre-loaded into the spacecraft’s computer, helping OSIRIS-REx determine its location relative to the asteroid.

With its sample secured in the return capsule, OSIRIS-REx is set to depart the vicinity of asteroid Bennu next year to begin the trip back to Earth. The spacecraft will release the return capsule for re-entry into Earth’s atmosphere and landing at the Utah Test and Training Range on Sept. 24, 2023.

Artist’s illustration of the OSIRIS-REx spacecraft with its sampling arm extended. Credit: NASA

NASA’s $1 billion Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer mission launched Sept. 8, 2016, from Cape Canaveral aboard a United Launch Alliance Atlas 5 rocket. OSIRIS-REx’s primary goal is to return asteroid samples to Earth for detailed analysis by scientists, who hope to uncover clues about the origins of the solar system.

The mission requirement was for OSIRIS-REx to gather at least 60 grams, or 2.1 ounces, of asteroid material. Scientists said before the Oct. 20 touch and go landing that the spacecraft could collect much more, and evidence suggests it likely snared more than 2.2 pounds, or 1 kilogram, of asteroid specimens, according to Dante Lauretta, the mission’s principal investigator from the University of Arizona.

Data from the brief touchdown on the asteroid indicated the spacecraft’s robotic arm sunk up to 19 inches (48 centimeters) into the Bennu’s soft surface.

While the mission’s scientific payoff will wait until the asteroid samples return to Earth, Lauretta said Thursday that scientists are already learning about the physical characteristics of Bennu.

The spacecraft detected small particles flying off Bennu soon after it arrived at the asteroid in December 2018. Those particles appear similar to the flaky material that leaked out of the TAGSAM head.

“It looks like a box of cornflakes out in space,” Lauretta said. “And they’re fluttering around kind of in random motion. They are coming from the TAGSAM head for the most part, but they are colliding with each other. They’re spinning and tumbling. We can resolve many of them.

“So it’s a great imaging calibration data set to better understand the particle ejection events, and the particles trajectories that we observed throughout the entire encounter with the asteroid,” Lauretta said. “Wven though my heart breaks for the loss of sample, it turned out to be a pretty cool science experiment.”

OSIRIS-REx’s contact with the asteroid surface Oct. 20 also provided a rich dataset, suggesting the outer layer of the asteroid’s soil and low-density rocks lacked much cohesion. The spacecraft’s robotic arm touched the asteroid as OSIRIS-REx approached at just 0.2 mph, or 10 centiemters per second, about a tenth the speed of a typical walking pace.

“When the TAGSAM head made contact with the regolith, it just flowed away like a fluid,” Lauretta said. “And I think that’s what would happen to an astronaut if she were to attempt to walk on the surface of the asteroid. She would sink to her knees or deeper — depending on how loose the soil was — until you hit a larger boulder or some kind of bedrock.”

He said the “ground truth” data gathered by OSIRIS-REx will help scientists reexamine models of asteroid geology.

“It’s fascinating that there was so little resistance to the spacecraft from the asteroid surface,” Lauretta said. “Basically, it’s kind of like a ball pit at a kid’s playground. You kind of jump into it and you just sink in.

“Luckily, we had those back-away thrusters to reverse the direction of motion, or we might have just flown all the way through the asteroid,” Lauretta joked.

The fresh measurements of asteroid density from OSIRIS-REx will help scientists refine assessments of the impact risk Bennu might pose to Earth. Scientists have calculated a 1-in-2,700 probability that Bennu might strike Earth in the late 2100s.

Much of the asteroid might burn up in Earth’s atmosphere due to its porosity.

“Thermal analysis indicates that a lot of the material on the surface of Bennu — particularly the large black hummocky boulders which are a major component of the surface — they seem to have material properties that would not survive passage through the atmosphere intact,” Lauretta said. “They would fragment, and much of the material will be lost.”

That means the pristine specimens collected from Bennu are unlike any meteorites or asteroid fragments that have fallen to Earth and reached the surface intact.

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Follow Stephen Clark on Twitter: @StephenClark1.

Mississippi's Racism Is On Its Ballot. Now Black Residents Must Fight A Pandemic And Lines To Vote.

“It used to be Southerners didn't want Blacks to vote because they're Black. Now they don’t want them to vote because they're Democrats.”

Emmanuel FeltonBuzzFeed News Reporter

Posted on November 2, 2020

Barbara Gauntt / Reuters
A campaign rally for Democratic Senate candidate Mike Espy in Jackson, Mississippi, Sept. 3, 2020.

Black Mississippians who go to the polls Tuesday will likely be waiting in long lines, and potentially be exposed to a lethal virus that has disproportionately hurt their communities, after state Republicans refused to loosen voting restrictions in the midst of the pandemic.

There’s a lot more on the ballot than just the presidential election: The people of Mississippi will be deciding between a sitting Republican senator with a history of racist remarks and a former US secretary of agriculture who would be the first Black senator from Mississippi since Reconstruction.

They will be deciding whether to replace a confederate symbol on the state flag.

And they will vote on the fate of a Jim Crow–era law that effectively makes it impossible for a Black person to win statewide office, because it requires governors and other state leaders to win a majority of the statewide vote as well as secure the most votes in a majority of 122 state House districts.

Local election officials are predicting record turnout and long lines across Mississippi on Election Day, in the only state nationwide where lawmakers didn’t give citizens either the option to vote early in person or to mail in a ballot during the COVID-19 pandemic. The legislature only expanded early voting to people who were under physician-order quarantine — which some officials say requires a doctor’s note — or who were taking care of someone in quarantine.

“It's already a lot busier,” said Jackie Jackson, deputy circuit clerk in Jefferson County, who said, even under the state’s strict rules, the county had already been seeing more absentee voters turn up at their office than she can remember over her over 20 years working there. “It’s probably going to be the busiest Election Day I've at least seen.”

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Some voting rights advocates are worried that amid a new surge in coronavirus cases, Black Mississippians in particular will have to decide between risking their health and exercising their right to vote.

Over 1,300 Black people in the state have died from COVID-19 so far, and while there has been a recent spike in deaths among white Mississippians, Black residents are still 2.5 times more likely to die of the disease.

Mississippi’s voting laws have long been among the most restrictive in the nation with few expansions to access since the Voting Rights Act of 1965 but additional restrictions like a new voter ID law in 2014. Unlike in many other states, Republican leaders made little effort to expand voting access in light of the extraordinary concerns over health and safety during the pandemic. In a pair of lawsuits, advocates pushed for broader exemptions but were largely unsuccessful.

“It used to be Southerners didn't want Blacks to vote because they're Black. Now they don’t want them to vote because they're Democrats,” said Robert Howard, a political science professor at Georgia State University who studies Southern politics.

He added that it’s hard to disentangle any decisions on voting procedures from issues of race in the South.

In September, the Mississippi Supreme Court reversed a lower court decision and ruled that people with medical conditions that put them at higher risk of severe complications from COVID-19 were not automatically entitled to an absentee ballot. That was after Republican Secretary of State Michael Watson appealed a state court’s decision approving the protections.

State law does allow Mississippians with disabilities to vote early — but Robert McDuff, the civil rights lawyer pushing for expanded protections in the case, said the Supreme Court’s decision leaves it open to county clerks to decide who does and doesn't qualify as having a temporary disability during the pandemic.


Rogelio V. Solis / AP
A woman in a face mask walks past a sign encouraging voters to vote absentee in light of COVID-19 precautions on the grounds of the Hinds County Courthouse in Jackson, Mississippi, Oct. 6, 2020.

As of Oct. 25, the last time Watson issued an update, over 142,591 Mississippians had voted early. That’s a record for the state, but Mississippians have cast just 12% of the total number of ballots in 2016. As of Sunday, voters nationally have cast over two-thirds of the total number of ballots cast in 2016. In nearby states with more robust early voting laws like Tennessee, Georgia, and Florida, voters have already cast over 80% of the total ballots they cast in the last presidential election. Texas surpassed its total number of votes cast in 2016 by the time early voting closed on Friday.

Given how much harder Black communities in the state have been hit by COVID-19, voting rights activists say the state’s lack of accommodations for the pandemic is just the latest in a long line of efforts to suppress the votes of the Black community.

Mississippi has among the most racially polarized electorates in the country. Black Mississippians overwhelmingly vote for Black politicians and Democrats, while the vast majority of white voters there vote for white Republican candidates. And like elsewhere in the country, masks have become wrapped up in politics.

“The Republicans perceived that it would be in their political interest to discourage people from voting,” said McDuff. “Particularly low-income people, particularly people who would be following public health guidelines more strictly, because those people are perceived to be Democrats not Republicans, generally speaking.”

While the state’s first wave hit its Black community hardest, as the election approaches, Mississippi is experiencing a second wave of coronavirus cases fueled by white Mississippians who refuse to wear masks, said Dr. Thomas Dobbs, the top health officer in Mississippi.

“We have had really pretty good uptake by a lot of folks in the Black community with masking and social distancing,” Dobbs said on a call with reporters. “And I just want to say that I think big parts of the white community, especially in areas that maybe weren’t as hard-affected [this summer], have not been as compliant or engaged actively with social distancing and masking. And I think that does make a difference.”

Republican Gov. Tate Reeves let the statewide mask order expire at the end of September, but county clerks are assuring voters that polling locations will be safe. Under regulations handed down by the secretary of state, poll workers, poll watchers, and elected officials must wear masks in the precinct. Voters, however, won’t be turned away if they refuse to wear a mask.

Barbara Gauntt / Reuters

An Espy supporter at a drive-in style campaign rally in Jackson, Mississippi, Sept. 3, 2020.

Voting rights advocates like Oleta Fitzgerald, director of the Children’s Defense Fund’s southern regional office, are worried about unmasked white voters showing up at the polls and intimidating Black voters.

"They know the population most at risk are people of color, and so not expanding early and absentee voting during this pandemic was a backdoor way of trying to decrease turnout,” said Fitzgerald.

Even with limited early voting, long lines have already been reported at the circuit clerk’s office in Hinds County, the most populous county in the state and a Democratic stronghold, where a record 13,000 absentee ballots have been cast. That picture differs across the state. In counties where Black and white voters are more evenly split and Republicans have control of the county clerk’s office, there have been far fewer absentee ballots cast. Part of the concern for advocates is that so much is left up to how accommodating county clerks want to be to voters concerned about COVID-19.

Fitzgerald is worried about places like Jones County, where election commissioner Gail Welch posted on social media earlier this year to warn about an increase in Black voter registration there in the wake of the effort to remove the Confederate symbol from the state flag.

“The blacks are having lots [of] events for voter registration. People in Mississippi have to get involved, too,” she wrote on Facebook.

“So far, we've seen county clerks in majority Black counties are being a lot more lenient with how they read the rules related to the COVID, they're also allowing some leniency in terms of the fear that you've got some other kind of health issues,” said Fitzgerald.

“Right now, what I’m concerned about is voter protection on Election Day. We have a number of counties that are majority white but have large Black communities. There’s where we’re concerned that there might be some efforts to intimidate those folks on Election Day. So the poll monitoring, poll watching all of that is more critical than ever, especially with all the dog whistles that have gone off this year,” she said, referring to President Donald Trump’s campaign rhetoric.

Others are more hopeful that despite the challenges, the system will work for voters in Mississippi tomorrow.

“Mississippi is a horrible place to try to vote in, but I think that our circuit clerks and our election commissions are doing everything that they possibly can,” said Christy Wheeler, co-president of the Mississippi League of Women Voters. “I think that we will see a huge turnout and that we may have lines, but I absolutely believe that because if they show up by 7 p.m., even though there might be long lines, they'll get the opportunity to vote.”

Voters will be deciding whether to reelect Republican Sen. Cindy Hyde-Smith, who gathered national headlines in 2018 when she said of a supporter, “If he invited me to a public hanging, I’d be on the front row.”

Rogelio V. Solis / AP
Incumbent Republican US Sen. Cindy Hyde-Smith gestures as she speaks at a campaign stop at the Richland, Mississippi, City Hall, Oct. 29, 2020.

Around the same time, CNN dug up 2014 photos from her Facebook page, in which she is posing in a Confederate soldier hat with an old Civil War rifle in hand; she captioned the photo, “Mississippi history at its best!” Hyde-Smith defeated her Black Democratic opponent Mike Espy by 7 points in a 2018 special election.

The two are set for a rematch on Tuesday. There have been few polls in the race, though one last week showed Hyde-Smith up by 8 points. Espy, for his part, has said the election will come down to Black turnout and he's hoping for that to be higher than the previous records set when President Barack Obama was on the ballot.

In the same poll that had Espy down by 8 points, 61% of voters supported changing the state flag and a small majority supported repealing the law requiring statewide candidates to win in a majority of the 122 state house districts. Opponents of that law say it dilutes the Black vote and makes it all but impossible to elect a Black candidate to statewide office since the candidate would also have to secure support in heavily white communities.

“Justice is on the ballot,” said Fitzgerald. “Safe and healthy schools are on the ballot. Childcare and healthcare are on the ballot. Financial support for small businesses that are being left is on the ballot. And then we say, Jim Crow is on the ballot.”

Arekia Bennett, executive director of the nonpartisan Mississippi Votes, said she knows that voters will be facing even more challenges than usual this year, but she’s hopeful Mississippians won’t be deterred, given everything that’s at stake.

“We've got the senatorial race, we've got folks running for our supreme court, and we also have three ballot measures,” said Bennett. “There's one to remove the 1890 Jim Crow law. We get to vote for the flag, and we get to vote for or against the usage of medical marijuana. We need people to show up and make their voices heard like never before here, because we've got an opportunity of a lifetime to make some drastic changes.”




Emmanuel Felton is an investigative reporter for BuzzFeed News and is based in New York.

A Judge Blocked A Trump Policy That Allowed Officials To Deny Residency To Immigrants Who Might Use Public Benefits

The policy had allowed officials to deny green cards to immigrants who were deemed likely to use Section 8 housing vouchers, most forms of Medicaid, and other assistance.

Hamed Aleaziz  BuzzFeed News Reporter


Last updated on November 2, 2020

Elliot Spagat / AP

Immigrants in Tijuana, Mexico, listen to names being called from a waiting list to claim asylum at a border crossing in San Diego on Sept. 26, 2019.

A federal judge on Monday blocked a key Trump administration policy that allows the government to deny permanent residency to immigrants who officials believe are likely to use public benefits.

The ruling by US District Court Judge Gary Feinerman is the latest in the back-and-forth legal saga over the “public charge” policy, which was a major initiative pushed by the Trump administration in its efforts to restrict immigration.

Immigrant advocates have long said the policy would change the face of immigration and discourage people from seeking public benefits, such as Medicaid. In recent months, they have warned the impact would be especially acute during the pandemic as immigrants weigh whether to enroll in publicly funded healthcare coverage.

In the less than a year since it’s been implemented, the policy has been blocked multiple times, though the administration has been successful in lifting the previous rulings. After Feinerman’s order in the Northern District of Illinois, a US Citizenship and Immigration Services (USCIS) official emailed immigration officers across the country informing them that the “judgment is applicable nationwide and is effective immediately.”

“USCIS must immediately cease implementing the public charge final rule,” wrote Daniel Renaud, a lead USCIS official. A spokesperson for USCIS also said in a statement that the agency "will fully comply with the decision and issue additional forthcoming guidance while the agency reviews the decision."

The Immigration and Nationality Act has long allowed the government to reject granting permanent residency to immigrants who were determined to be a financial burden on society, or a public charge, meaning they’re dependent on the government for financial support.

The Trump administration’s rule, however, altered how the government decides if someone is a public charge, allowing officials to deny green cards to those who are deemed likely to use the Supplemental Nutrition Assistance Program (SNAP), Section 8 housing vouchers, and assistance, public housing, or most forms of Medicaid.

The policy was implemented in late February.

“Donald Trump has continually tried to instill policies that penalize diversity. His administration’s attempt to shortchange immigrants by changing public charge threatens our public health and destroys communities that have immigrant populations who make these places across America great,” said Cook County State’s Attorney Kim Foxx, which brought the lawsuit that led to the ruling on Monday.

Groups help homeless overcome challenges to voting

Washington, D.C., residents experiencing homelessness register to vote in the 2020 election at a Pathways to Housing DC event. Photo courtesy of Pathways to Housing DC

WASHINGTON, Nov. 2 (UPI) -- As Americans face unprecedented challenges to voting amid the COVID-19 pandemic, the homeless community appears poised to cast tens of thousands of ballots this year, spurred by mobilization efforts and interest in the election, advocacy groups say.

An estimated 567,000 people experienced homelessness on any given night in 2019, according to the Department of Housing and Urban Development's annual Point-in-Time count. Brendan O'Flaherty, a professor of economics at Columbia University, predicted that this number could be as much as 45% higher due to the pandemic, an addition of nearly 250,000 people.

Studies have shown that an average of 60% of the homeless population are eligible voters, which would add up to about 340,000 to 490,000 people given the estimated increase this year.

Many leaders who work with the homeless said they have helped larger numbers register, get ballots or vote early than in the past.

Nan Roman, president and CEO of the National Alliance to End Homelessness, heads the organization's national Every One Votes campaign encouraging groups working with the homeless to incorporate voting into their efforts.

Roman said she doesn't have data on how many homeless people have cast votes so far this year, "But...the feedback has been really good. And I think we've got...a lot more people...We've pushed it harder this year."

'I have to participate'

Christina Giles, a 41-year-old D.C. native experiencing homelessness, cast her ballot through early voting last week for the first time in years.

"I have to participate in the politics to stop things from happening," Giles said, referring to injustices toward the Black community. A student at Strayer University, she said she has always been interested in politics and activism, but that she made sure to vote this year because she believes much is at stake.

The voting rate among the homeless population is historically one of the lowest in the nation. Just 41% of eligible voters who earn less than $10,000 a year voted in 2016 -- the lowest of any income group, according to the Census Bureau. A 2012 study by the National Coalition for the Homeless found that voters experiencing homelessness are estimated to vote only about 10% of the time compared with an average of 54% nationally.

Although a seris of court cases in the 1980s confirmed that the homeless could not be denied the right to vote for lacking a traditional residence, each state maintains its own requirements for establishing residency within a certain precinct. In D.C., homeless people can use the address of a shelter or social services provider to register by providing a government-issued document or a letter from a service provider attesting to the applicant's living situation.

Giles said voting this year was "super easy" because she was homeless and eligible for many services, like voting assistance. She received help casting a ballot through Pathways to Housing D.C., a Housing First provider that launched a new get-out-the-vote campaign this year.

The initiative was formed after demonstrations that erupted this spring over systematic racism and inequality


"That's another misconception that a lot of people have about people experiencing homelessness -- that they're not interested," said Briana Perez-Brennan, who heads the voting campaign at Pathways. She said that for many people, it comes down to being "recognized as a human being" and the realization that "my voice matters."

"And that's so huge," she said. "Especially in the context of this election."

Lack of address

Perez-Brennan said the group has registered more than 100 new voters.

Turnout for Tuesday's election has beaten many records already, with a surge in early and mail-in-voting. Although most of the U.S. homeless population live in urban areas like New York City and Los Angeles, swing states like Arizona, Florida, Georgia and Pennsylvania had estimated pre-pandemic homeless populations of 10,000 to 30,000 on any given night in 2019, a range which could now be 14,500 to 43,500 due to the coronavirus. That could translate to thousands of homeless votes in states with razor- thin margins.

Homeless voters have always faced struggles casting a ballot because they lack an address, ID, transportation, Internet connections or access to other resources. This reality is made more difficult by some new anti-fraud voting laws like the Help America Vote Act, passed in 2002 to curtail voting irregularities seen during the 2000 election.

The law ultimately led to an intensification of residency and identification requirements in many states, two particularly difficult aspects of the voting process for the homeless who may not have an up-to-date ID or an address. Disenfranchisement of the disabled, immigrants and felons also disproportionately affects the homeless.

The pandemic has only complicated matters.

Many shelters have had to limit intake or shut down to meet safety guidelines, while the number of volunteers contributing time to shelters and programs like the voter campaign has decreased. Displacement between shelters is more common, as is breaking up informal encampments, making transport to the polls or mailing in ballots more difficult. And like other Americans, the homeless also face long lines, confusing instructions and COVID-19 fears if they go to polling places.

Maisha Pinkard, director of Friendship Place homeless shelter in D.C., said her team has recently helped register clients to vote and use the office as an address for their mail-in ballots or voter ID cards. Pinkard said more than 100 of her clients requested ballots; her group helped them get the ballots completed and in the mail.

Shelters like Pathways plan to incorporate voter registration into their on-boarding processes permanently."Now it's a movement, it's like a cultural thing," Giles said about voting and protesting injustice within her community. She said she now is bringing up voting with others struggling with homelessness.

"Now I don't have to be alone. There are people I can share it with and people I can talk to about it who are listening," she said.


upi.com/7051807

New remote sensing technique could bring key planetary mineral into focus

BROWN UNIVERSITY

Research News

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IMAGE: A MOUNTAIN PEAK AT THE CENTER OF THE MOON'S COPERNICUS CRATER HAS AN ABUNDANCE OF OLIVINE, A MINERAL THAT CAN HELP SCIENTISTS UNDERSTAND THE INTERNAL EVOLUTION OF PLANETARY BODIES. A... view more 

CREDIT: NASA/GSFC/ARIZONA STATE UNIVERSITY

PROVIDENCE, R.I. [Brown University] -- Planetary scientists from Brown University have developed a new remote sensing method for studying olivine, a mineral that could help scientists understand the early evolution of the Moon, Mars and other planetary bodies.

"Olivine is understood to be a major component in the interiors of rocky planets," said Christopher Kremer, a Ph.D. candidate at Brown University and lead author of a new paper describing the work. "It's a primary constituent of Earth's mantle, and it's been detected on the surfaces of the Moon and Mars in volcanic deposits or in impact craters that bring up material from the subsurface."

Current remote sensing techniques are good at spotting olivine from orbit, Kremer says, but scientists would like to do more than just spot it. They'd like to be able to learn more about its chemical makeup. All olivines have silicon and oxygen, but some are rich in iron while others have lots of magnesium.

"The composition tells us something about the environment in which the minerals formed, particularly the temperature," Kremer said. "Higher temperatures during formation yield more magnesium, while lower temperatures yield more iron. Being able to tease out those compositions could tell us something about how the interiors of these planetary bodies have evolved since their formation."

To find out if there might be a way to see that composition using remote sensing, Kremer worked with Brown professors Carlé Pieters and Jack Mustard, as well as mountains of data from the Keck/NASA Reflectance Experiment Laboratory (RELAB), which is housed at Brown.

One method researchers use to study rocks on other planetary bodies is spectroscopy. Particular elements or compounds reflect or absorb different wavelengths of light to various degrees. By looking at the light spectra rocks reflect, scientists can get an idea of what compounds are present. RELAB makes high-precision spectral measurements of samples for which the composition is already determined using other laboratory techniques. By doing that, the lab provides a ground truth for interpreting spectral measurements taken by spacecraft looking at other planetary bodies.

In poring through data from olivine samples examined over the years at RELAB, Kremer found something interesting hiding in a small swath of wavelengths that's overlooked by the kinds of spectroscopes that fly on orbital spacecraft.

"Over the past few decades, there's been a lot of interest in near infrared spectroscopy and middle infrared spectroscopy," Kremer said. "But there's a small range of wavelengths between those two that's left out, and those are the wavelengths I was looking at."

Kremer found that those wavelengths, a band between 4 and 8 microns, could predict the amount of magnesium or iron in an olivine sample to within about 10% of the actual content. That's far better than can be done when those wavelengths are ignored.

"With the instruments we have now, we could say maybe we have a little bit of this or a little bit of that," Mustard said. "But with this we're able to really put a number on it, which is a big step forward."

The researchers hope that this study, which is published in Geophysical Research Letters, might provide the impetus to build and fly a spectrometer that captures these previously overlooked wavelengths. Such an instrument could pay immediate dividends in understanding the nature of olivine deposits on the Moon's surface, Kremer says.

"The olivine samples brought back during the Apollo program that we've been able to study here on Earth vary widely in magnesium composition," Kremer said. "But we don't know how those differing compositions are distributed on the Moon itself, because we can't see those compositions spectroscopically. That's where this new technique comes in. If we could figure out a pattern to how those deposits are distributed, it could tell us something about the early evolution of the Moon."

There's the potential for other discoveries as well. The airplane-based SOFIA telescope is one of the few non-lab instruments that can look in this forgotten frequency range. The instrument's recent detection of water molecules in sunlit lunar surfaces made use of those frequencies.

"That makes the idea of space-borne spectrometers that can see this range much more attractive, both for water and for rocky material like olivine," Kremer said.

###

The research was supported through NASA SSERVI (NNA14AB01A) and a NASA FINESST grant.

 

Covid-19 "super-spreading" events play outsized role in overall disease transmission

Mathematical analysis suggests that preventing large gatherings could significantly reduce Covid-19 infection rates.

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Research News

 

CAMBRIDGE, MA -- There have been many documented cases of Covid-19 "super-spreading" events, in which one person infected with the SARS-CoV-2 virus infects many other people. But how much of a role do these events play in the overall spread of the disease? A new study from MIT suggests that they have a much larger impact than expected.

The study of about 60 super-spreading events shows that events where one person infects more than six other people are much more common than would be expected if the range of transmission rates followed statistical distributions commonly used in epidemiology.

Based on their findings, the researchers also developed a mathematical model of Covid-19 transmission, which they used to show that limiting gatherings to 10 or fewer people could significantly reduce the number of super-spreading events and lower the overall number of infections.

"Super-spreading events are likely more important than most of us had initially realized. Even though they are extreme events, they are probable and thus are likely occurring at a higher frequency than we thought. If we can control the super-spreading events, we have a much greater chance of getting this pandemic under control," says James Collins, the Termeer Professor of Medical Engineering and Science in MIT's Institute for Medical Engineering and Science (IMES) and Department of Biological Engineering and the senior author of the new study.

MIT postdoc Felix Wong is the lead author of the paper, which appears this week in the Proceedings of the National Academy of Sciences.

Extreme events

For the SARS-CoV-2 virus, the "basic reproduction number" is around 3, meaning that on average, each person infected with the virus will spread it to about three other people. However, this number varies widely from person to person. Some individuals don't spread the disease to anyone else, while "super-spreaders" can infect dozens of people. Wong and Collins set out to analyze the statistics of these super-spreading events.

"We figured that an analysis that's rooted in looking at super-spreading events and how they happened in the past can inform how we should propose strategies of dealing with, and better controlling, the outbreak," Wong says.

The researchers defined super-spreaders as individuals who passed the virus to more than six other people. Using this definition, they identified 45 super-spreading events from the current SARS-CoV-2 pandemic and 15 additional events from the 2003 SARS-CoV outbreak, all documented in scientific journal articles. During most of these events, between 10 and 55 people were infected, but two of them, both from the 2003 outbreak, involved more than 100 people.

Given commonly used statistical distributions in which the typical patient infects three others, events in which the disease spreads to dozens of people would be considered very unlikely. For instance, a normal distribution would resemble a bell jar with a peak around three, with a rapidly-tapering tail in both directions. In this scenario, the probability of an extreme event declines exponentially as the number of infections moves farther from the average of three.

However, the MIT team found that this was not the case for coronavirus super-spreading events. To perform their analysis, the researchers used mathematical tools from the field of extreme value theory, which is used to quantify the risk of so-called "fat-tail" events. Extreme value theory is used to model situations in which extreme events form a large tail instead of a tapering tail. This theory is often applied in fields such as finance and insurance to model the risk of extreme events, and it is also used to model the frequency of catastrophic weather events such as tornadoes.

Using these mathematical tools, the researchers found that the distribution of coronavirus transmissions has a large tail, implying that even though super-spreading events are extreme, they are still likely to occur.

"This means that the probability of extreme events decays more slowly than one would have expected," Wong says. "These really large super-spreading events, with between 10 and 100 people infected, are much more common than we had anticipated."

Stopping the spread

Many factors may contribute to making someone a super-spreader, including their viral load and other biological factors. The researchers did not address those in this study, but they did model the role of connectivity, defined as the number of people that an infected person comes into contact with.

To study the effects of connectivity, the researchers created and compared two mathematical network models of disease transmission. In each model, the average number of contacts per person was 10. However, they designed one model to have an exponentially declining distribution of contacts, while the other model had a fat tail in which some people had many contacts. In that model, many more people became infected through super-spreader events. Transmission stopped, however, when people with more than 10 contacts were taken out of the network and assumed to be unable to catch the virus.

The findings suggest that preventing super-spreading events could have a significant impact on the overall transmission of Covid-19, the researchers say.

"It gives us a handle as to how we could control the ongoing pandemic, which is by identifying strategies that target super-spreaders," Wong says. "One way to do that would be to, for instance, prevent anyone from interacting with over 10 people at a large gathering."

The researchers now hope to study how biological factors might also contribute to super-spreading.

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The research was funded by the James S. McDonnell Foundation.

AMERICAN RACISM

Discrimination increases against Asian and Asian American population, affecting health

WASHINGTON STATE UNIVERSITY

Research News

 

VANCOUVER, Wash. - Reports of racial discrimination against Asians and Asian-Americans have increased since the start of the COVID-19 pandemic hit the United States, coinciding with an increase in reported negative health symptoms.

That's according to a new paper written by Washington State University researchers recently published in the journal Stigma and Health.

"When COVID hit, we were quickly hearing anecdotes on social media and in traditional media about Asian-Americans experiencing a variety of racial abuse," said Sara Waters, an assistant professor in WSU's Department of Human Development on the Vancouver campus.

To look into the scope of those anecdotes, Waters and her graduate student, Suyeon Lee, a Ph.D. candidate in WSU's Prevention Science program, created a survey. Over 400 people responded, with almost 30% saying they experienced more discrimination since the pandemic started and 40% experienced more health impacts.

"We expected that people who experience racism would report more health issues," Waters said. "But we were surprised by just how much that increased."

The racial discrimination was above and beyond the increased stress levels experienced by the general public, Waters said.

The survey contained questions about four mental and physical health outcomes: anxiety, depressive and physical symptoms, and sleep difficulties. It also asked people to provide specific examples of racial discrimination they faced. Responses ranged from microaggressions, like people glaring or changing lines at a supermarket, to more direct actions.

"Some of those were very hard to read," Waters said. "One person described walking past a group of children who told her to go back to her country and called her 'Coronavirus.' Another was threatened with a knife. Terms like 'kung flu' and 'China virus' were very common in responses. Words used often by people in leadership positions in our country are filtering down."

Experiencing those kinds of abuse impacts a person's mental and physical health in a variety of ways. For physical health, Lee and Waters asked people to rate any increases in symptoms like headaches, backaches, nausea, and other general physical maladies. For sleep difficulties, they used the established Pittsburgh Sleep Quality Index.

"Sleep can be an important indicator of mental well-being," Waters said.

One way the survey results showed people can buffer the impact that discrimination has on health is by having social support.

Respondents who reported increased discrimination, but also report having more social support, had fewer health, especially depression, symptoms.

"That's another problem. In this era of quarantine and social distancing, it can be harder to get that beneficial social support," Waters said.

The researchers conducted their survey over a few weeks in May and June, starting roughly two months after the pandemic hit the U.S.

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 AMERICAN RACISM

Study suggests increased risk of restraint use in black patients in the emergency setting

SOCIETY FOR ACADEMIC EMERGENCY MEDICINE

Research News

 

IMAGE: PATIENT VISITS AT MASSACHUSETTS GENERAL HOSPITAL (2016-2018). view more 

CREDIT: KIRSTY CHALLEN, B.SC., MBCHB, MRES, PH.D., LANCASHIRE TEACHING HOSPITALS, UNITED KINGDOM

DES PLAINES, IL -- A study published in the most recent issue of Academic Emergency Medicine (AEM), journal showed an increased risk of restraint use in Black patients compared with white patients in the emergency setting. The risk was not increased in other races or Hispanic/Latino ethnicity.

The lead author of the single-center study is Dr. Kristina Schnitzer MD, a psychiatrist in the Schizophrenia Clinical and Research Program at Massachusetts General Hospital and an instructor at Harvard Medical School. The findings of the study are discussed with two of the authors in episode 43 of AEM Early Access, a FOAMed podcast collaboration between the Academic Emergency Medicine Journal and Brown Emergency Medicine.

The increased risk of restraint was present in Black patients after controlling for other variables, including repeated visits, using a specialized regression technique. Concerning data also showed that 7-8 percent of all patients with psychosis or bipolar disorder, and six percent of all homeless patients were restrained. The study also identifies that there is an increased risk of patients to be restrained who are on public insurance or uninsured.

The study results warrant a careful examination of current practices and potential biases in utilization of restraint in emergency settings.

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ABOUT ACADEMIC EMERGENCY MEDICINE

Academic Emergency Medicine, the monthly journal of Society for Academic Emergency Medicine, features the best in peer-reviewed, cutting-edge original research relevant to the practice and investigation of emergency care. The above study is published open access and can be downloaded by following the DOI link: 10.1111/acem.14092. Journalists wishing to interview the authors may contact Stacey Roseen at sroseen@saem.org.

ABOUT THE SOCIETY FOR ACADEMIC EMERGENCY MEDICINE

SAEM is a 501(c)(3) not-for-profit organization dedicated to the improvement of care of the acutely ill and injured patient by leading the advancement of academic emergency medicine through education and research, advocacy, and professional development. To learn more, visit saem.org.

Solar cells of the future

Young researcher at FAU develops system for increasing the efficiency of organic solar cells.

UNIVERSITY OF ERLANGEN-NUREMBERG

Research News

 

Organic solar cells are cheaper to produce and more flexible than their counterparts made of crystalline silicon, but do not offer the same level of efficiency or stability. A group of researchers led by Prof. Christoph Brabec, Director of the Institute of Materials for Electronics and Energy Technology (i-MEET) at the Chair of Materials Science and Engineering at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), have been working on improving these properties for several years. During his doctoral thesis, Andrej Classen, who is a young researcher at FAU, demonstrated that efficiency can be increased using luminescent acceptor molecules. His work has now been published in the journal Nature Energy.

The sun can supply radiation energy of around 1000 watts per square metre on a clear day at European latitudes. Conventional monocrystalline silicon solar cells convert up to a fifth of this energy into electricity, which means they have an efficiency of around 20 percent. Prof. Brabec's working group has held the world record for efficiency in an organic photovoltaic module of 12.6% since September 2019. The multi-cell module developed at Energie Campus Nürnberg (EnCN) has a surface area of 26 cm². 'If we can achieve over 20% in the laboratory, we could possibly achieve 15% in practice and become real competition for silicon solar cells,' says Prof. Brabec.

Flexible application and high energy efficiency during manufacturing

The advantages of organic solar cells are obvious - they are thin and flexible like foil and can be adapted to fit various substrates. The wavelength at which the sunlight is absorbed can be 'adjusted' via the macromodules used. An office window coated with organic solar cells that absorbs the red and infrared spectrum would not only screen out thermal radiation, but also generate electricity at the same time. One criterion that is becoming increasingly important in view of climate change is the operation period after which a solar cell generates more energy than was required to manufacture it. This so-called energy payback time is heavily dependent on the technology used and the location of the photovoltaic (PV) system. According to the latest calculations of the Fraunhofer Institute for Solar Energy Systems (ISE), the energy payback time of PV modules made of silicon in Switzerland is around 2.5 to 2.8 years. However, this time is reduced to only a few months for organic solar cells according to Dr. Thomas Heumüller, research associate at Prof. Brabec's Chair.

Loss of performance for charge separation

Compared with a 'traditional' silicon solar cell, its organic equivalent has a definite disadvantage: Sunlight does not immediately produce charge for the flow of current, but rather so-called excitons in which the positive and negative charges are still bound. 'An acceptor that only attracts the negative charge is required in order to trigger charge separation, which in turn produces free charges with which electricity can be generated,' explains Dr. Heumüller. A certain driving force is required to separate the charges. This driving force depends on the molecular structure of the polymers used. Since certain molecules from the fullerene class of materials have a high driving force they have been the preferred choice of electron acceptors in organic solar cells up to now. In the meantime, however, scientists have discovered that a high driving force has a detrimental effect on the voltage. This means that the output of the solar cell decreases, in accordance with the formula that applies to direct current - power equals voltage times current.

Andrej Classen wanted to find out how low the driving force has to be to just achieve complete charge separation of the exciton. To do so, he compared combinations of four donor and five acceptor polymers that have already proven their potential for use in organic solar cells. Classen used them to produce 20 solar cells under exactly the same conditions with a driving force of almost zero to 0.6 electronvolts.

Increase in performance with certain molecules

The measurement results provided the proof for a theory already assumed in research - a 'Boltzmann equilibrium' between excitons and separated charges, the so-called charge transfer (CT) states. 'The closer the driving force reaches zero, the more the equilibrium shifts towards the excitons,' says Dr. Larry Lüer who is a specialist for photophysics in Brabec's working group. This means that future research should concentrate on preventing the exciton from decaying, which means increasing its excitation 'lifetime'. Up to now, research has only focused on the operating life of the CT state. Excitons can decay by emitting light (luminescence) or heat. By skilfully modifying the polymers, the scientists were able to reduce the heat production to a minimum, retaining the luminescence as far as possible. 'The efficiency of solar cells can therefore be increased using highly luminescent acceptor molecules,' predicts Andrej Classen.

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'Transparent solar cells' can take us towards a new era of personalized energy

Scientists design novel transparent solar cells using thin silicon films, with efficient power generation

INCHEON NATIONAL UNIVERSITY

Research News

 

IMAGE: SCIENTISTS HAVE BEEN DEVELOPING TRANSPARENT SOLAR CELLS THAT MAY SOON FIND THEIR USE IN ALL KINDS OF DEVICES, INCLUDING BUILDINGS, VEHICLES, CELL PHONES, AND SENSORS view more 

CREDIT: JOEL FILIPE ON UNSPLASH

Today, the imminent climate change crisis demands a shift from conventionally used fossil fuels to efficient sources of green energy. This has led to researchers looking into the concept of "personalized energy," which would make on-site energy generation possible. For example, solar cells could possibly be integrated into windows, vehicles, cellphone screens, and other everyday products. But for this, it is important for the solar panels to be handy and transparent. To this end, scientists have recently developed "transparent photovoltaic" (TPV) devices--transparent versions of the traditional solar cell. Unlike the conventionally dark, opaque solar cells (which absorb visible light), TPVs make use of the "invisible" light that falls in the ultraviolet (UV) range.

Conventional solar cells can be either "wet type" (solution based) or "dry type" (made up of metal-oxide semiconductors). Of these, dry-type solar cells have a slight edge over the wet-type ones: they are more reliable, eco-friendly, and cost-effective. Moreover, metal-oxides are well-suited to make use of the UV light. Despite all this, however, the potential of metal-oxide TPVs has not been fully explored until now.

To this end, researchers from Incheon National University, Republic of Korea, came up with an innovative design for a metal-oxide-based TPV device. They inserted an ultra-thin layer of silicon (Si) between two transparent metal-oxide semiconductors with the goal of developing an efficient TPV device. These findings were published in a study in Nano Energy, which was made available online on August 10, 2020 (ahead of the scheduled final publication in the December 2020 issue). Prof Joondong Kim, who led the study, explains, "Our aim was to devise a high-power-producing transparent solar cell, by embedding an ultra-thin film of amorphous Si between zinc oxide and nickel oxide."

This novel design consisting of the Si film had three major advantages. First, it allowed for the utilization of longer-wavelength light (as opposed to bare TPVs). Second, it resulted in efficient photon collection. Third, it allowed for the faster transport of charged particles to the electrodes. Moreover, the design can potentially generate electricity even under low-light situations (for instance, on cloudy or rainy days). The scientists further confirmed the power-generating ability of the device by using it to operate the DC motor of a fan.

Based on these findings, the research team is optimistic that the real-life applicability of this new TPV design will soon be possible. As for potential applications, there are plenty, as Prof Kim explains, "We hope to extend the use of our TPV design to all kinds of material, right from glass buildings to mobile devices like electric cars, smartphones, and sensors." Not just this, the team is excited to take their design to the next level, by using innovative materials such as 2D semiconductors, nanocrystals of metal-oxides, and sulfide semiconductors. As Prof Kim concludes, "Our research is essential for a sustainable green future--especially to connect the clean energy system with no or minimal carbon footprint."

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Reference

Authors: Sangho Kim (1,2), Malkeshkumar Patel (1,2), Thanh Tai Nguyen (1,2), Junsin Yi (3), Ching-Ping Wong (4 ), Joondong Kim (1,2)

Title of original paper: Si-embedded metal oxide transparent solar cells

Journal: Nano Energy

DOI: 10.1016/j.nanoen.2020.105090

Affiliations:

(1) Photoelectric and Energy Device Application Lab (PEDAL), Multidisciplinary Core Institute for Future Energies (MCIFE), Incheon National University, Republic of Korea

(2) Department of Electrical Engineering, Incheon National University, Republic of Korea

(3) College of Information and Communication Engineering, SungKyunkwan University, Suwon, Republic of Korea

(4) School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, United States

About Incheon National University

Incheon National University (INU) is a comprehensive, student-focused university. It was founded in 1979 and given university status in 1988. One of the largest universities in South Korea, it houses nearly 14,000 students and 500 faculty members. In 2010, INU merged with Incheon City College to expand capacity and open more curricula. With its commitment to academic excellence and an unrelenting devotion to innovative research, INU offers its students real-world internship experiences. INU not only focuses on studying and learning but also strives to provide a supportive environment for students to follow their passion, grow, and, as their slogan says, be INspired.

Website: http://www.inu.ac.kr/mbshome/mbs/inuengl/index.html

About Professor Joondong Kim

Joondong Kim is a Professor at the Department of Electrical Engineering in Incheon National University, Korea, and the head of Multidisciplinary Core Institute for Future Energies (MCIFE). He majored in electrical engineering and earned his PhD in 2006 from the University at Buffalo, State University of New York, USA. His research is focused on the design of functional materials and neo-conception devices, neuromorphic memories, photosensors, and transparent photovoltaics. He has published about 220 SCI papers and holds 150 patents.