Eliana Willis

More stories

  • 175 Shares119 Views

    in Space & Astronomy

    How do you clean up clingy space dust? Zap it with an electron beam

    The NASA Artemis missions aim to send astronauts to the moon by 2024. But to succeed, they’ll need to solve big problems caused by some tiny particles: dust.
    Impacts on the moon’s surface have crushed lunar rock into dust over billions of years (SN: 1/17/19). The resulting particles are like “broken shards of glass,” says Mihály Horányi, a physicist at the University of Colorado Boulder. This abrasive material can damage equipment and even harm astronauts’ health if inhaled (SN: 12/3/13). Making matters worse, the sun’s radiation gives moon dust an electric charge, so it sticks to everything.
    Horányi and colleagues have discovered a new method for combatting lunar dust’s static cling, using a low-powered electron beam to make dust particles fly off surfaces. It complements existing approaches to the sticky problem, the researchers report online August 8 in Acta Astronautica.

    Sign Up For the Latest from Science News

    Headlines and summaries of the latest Science News articles, delivered to your inbox

    During the Apollo missions, astronauts relied on a low-tech system to clean lunar dust off their spacesuits: brushes. Such mechanical methods, however, are thwarted by the electrically charged nature of lunar dust, which clings to the nooks and crannies of woven spacesuit fabric.
    The newly described method takes advantage of the dust’s electrical properties. An electron beam causes dust to release electrons into the tiny spaces between particles. Some of these negatively charged electrons are absorbed by surrounding dust specks. Because the charged particles repel each other, the resulting electric field “ejects dust off the surface,” says Xu Wang, a physicist also at the University of Colorado Boulder.
    [embedded content]
    Abrasive, electrically charged lunar dust clings to surfaces and could wreak havoc on equipment and astronaut well-being during missions to the moon. An electron beam may aid future cleaning efforts. As shown here, when a beam hits artificial lunar dust on a glass plate, particles leap off the surface.
    “This is a very unique idea,” says mechanical engineer Hiroyuki Kawamoto of Waseda University in Tokyo, who was not involved in the new work. Kawamoto and colleagues have developed their own dust-busting technologies, including a layer of electrodes that can be built into materials. When embedded in a spacesuit or on the surface of equipment, the electrodes generate electrostatic forces and fling away charged dust particles. Such systems are more complex than shooting an electron beam at surfaces, Wang says. But a potential downside to the simpler electric beam idea, Kawamoto says, is that it would require a robot or some other external means to direct it.
    Another limitation of the electron beam is that it left behind 15 to 25 percent of dust particles. The researchers aim to improve the cleaning power. The team also envisions the electron beam as one of multiple approaches that future space explorers will take to keep surfaces clean, Horányi says, in addition to suit design, other cleaning technologies and, one day, even lunar habitats with moon dust mudrooms. More

  • 163 Shares109 Views

    in Space & Astronomy

    Phosphine gas found in Venus’ atmosphere may be ‘a possible sign of life’

    Venus’ clouds appear to contain a smelly, toxic gas that could be produced by bacteria, a new study suggests.
    Chemical signs of the gas phosphine have been spotted in observations of the Venusian atmosphere, researchers report September 14 in Nature Astronomy. Examining the atmosphere in millimeter wavelengths of light showed that the planet’s clouds appear to contain up to 20 parts per billion of phosphine — enough that something must be actively producing it, the researchers say. 
    If the discovery holds up, and if no other explanations for the gas are found, then the hellish planet next door could be the first to yield signs of extraterrestrial life — though those are very big ifs.
    “We’re not saying it’s life,” says astronomer Jane Greaves of Cardiff University in Wales. “We’re saying it’s a possible sign of life.”

    Sign Up For the Latest from Science News

    Headlines and summaries of the latest Science News articles, delivered to your inbox

    Venus has roughly the same mass and size as Earth, so, from far away, the neighboring planet might look like a habitable world (SN: 10/4/19). But up close, Venus is a scorching hellscape with sulfuric acid rain and crushing atmospheric pressures.
    Still, Venus might have been more hospitable in the recent past (SN: 8/26/16). And the current harsh conditions haven’t stopped astrobiologists from speculating about niches on Venus where present-day life could hang on, such as the temperate cloud decks.
    “Fifty kilometers above the surface of Venus, the conditions are what you would find if you walk out of your door right now,” at least in terms of atmospheric pressure and temperature, says planetary scientist Sanjay Limaye of the University of Wisconsin–Madison, who was not involved in the new study. The chemistry is alien, but “that’s a hospitable environment for life.”
    Previous work led by astrochemist Clara Sousa-Silva at MIT suggested that phosphine could be a promising biosignature, a chemical signature of life that can be detected in the atmospheres of other planets using Earth-based or space telescopes.
    On Earth, phosphine is associated with microbes or industrial activity — although that doesn’t mean it’s pleasant. “It’s a horrific molecule. It’s terrifying,” Sousa-Silva says. For most Earthly life, phosphine is poisonous because “it interferes with oxygen metabolism in a variety of macabre ways.” For anaerobic life, which does not use oxygen, “phosphine is not so evil,” Sousa-Silva says. Anaerobic microbes living in such places as sewage, swamps and the intestinal tracts of animals from penguins to people are the only known life-forms on Earth that produce the molecule.  
    Still, when Greaves and colleagues searched Venus’ skies for signs of phosphine, the researchers didn’t expect to actually find any. Greaves looked at Venus with the James Clerk Maxwell Telescope in Hawaii over five mornings in June 2017, aiming to set a detectability benchmark for future studies seeking the gas in the atmospheres of exoplanets (SN: 5/4/20), but was startled to find the hints of phosphine. “That’s a complete surprise,” Greaves says. When she was analyzing the observations, “I thought ‘Oh, I must have done it wrong.’”
    Signs of phosphine first showed up in data taken with the James Clerk Maxwell Telescope in Hawaii.Will Montgomerie/JCMT/EAO
    So the team checked again with a more powerful telescope, the Atacama Large Millimeter/submillimeter Array in Chile, in March 2019. But the signature of phosphine — seen as a dip in the spectrum of light at about 1.12 millimeters — was still there. The gas absorbs light in that wavelength. Some other molecules also absorb light near that wavelength, but those either couldn’t explain the whole signal or seemed improbable, Greaves says. “One of those is a plastic,” she says. “I think a floating plastic factory is a less plausible explanation than just saying there’s phosphine.”
    Phosphine takes a fair amount of energy to create and is easily destroyed by sunlight or sulfuric acid, which is found in Venus’ atmosphere. So if the gas was produced a long time ago, it shouldn’t still be detectable. “There has to be a source,” Greaves says.
    Greaves, Sousa-Silva and colleagues considered every explanation they could think of apart from life: atmospheric chemistry; ground and subsurface chemistry; volcanoes outgassing phosphine from the Venusian interior; meteorites peppering the atmosphere with phosphine from the outside; lightning; solar wind; tectonic plates sliding against each other. Some of those processes could produce trace amounts of phosphine, the team found, but orders of magnitude less than the team detected.
    “We’re at the end of our rope,” Sousa-Silva says. She hopes other scientists will come up with other explanations. “I’m curious what kind of exotic geochemistry people will come up with to explain this abiotically.”
    The idea of searching for life on Venus “has been regarded as a pretty out-there concept,” says Planetary Science Institute astrobiologist David Grinspoon, who is based in Washington, D.C. Grinspoon has been publishing about the prospects for life on Venus since 1997, but was not involved in the new discovery.
    “So now I hear about this, and I’m delighted,” he says. “Not because I want to declare victory and say this is definite evidence of life on Venus. It’s not. But it’s an intriguing signature that could be a sign of life on Venus. And it obligates us to go investigate further.”
    Because of the planet’s acidic atmosphere, extreme pressures and lead-melting temperatures, sending spacecraft to Venus is a challenge (SN: 2/13/18). But several space agencies are considering missions that could fly in the next few decades.
    In the meantime, Greaves and colleagues want to confirm the new phosphine detection in other wavelengths of light. Observations they had planned for the spring were put on hold by the coronavirus pandemic. And now, Venus is in a part of its orbit where it’s on the other side of the sun.
    “Maybe when Venus comes around on the other side of the sun again,” Greaves says, “things will be better for us here on Earth.” More

  • 150 Shares169 Views

    in Space & Astronomy

    Earth’s building blocks may have had far more water than previously thought

    Earth’s deep stores of water may have been locally sourced rather than trucked in from far-flung regions of the solar system.
    A new analysis of meteorites from the inner solar system — home to the four rocky planets — suggests that Earth’s building blocks delivered enough water to account for all the H2O buried within the planet. What’s more, the water produced by the local primordial building material likely shares a close chemical kinship with Earth’s deep-water reserves, thus strengthening the connection, researchers report in the Aug. 28 Science.
    Earth is thought to have been born in an interplanetary desert, too close to the sun for water ice to survive. Many researchers suspect that ocean water got delivered toward the end of Earth’s formation by ice-laden asteroids that wandered in from cooler, more distant regions of the solar system (SN: 5/6/15). But the ocean isn’t the planet’s largest water reservoir. Researchers estimate that Earth’s interior holds several times as much water as is found at the surface.
    To test whether or not the material that formed Earth could have delivered this deep water, cosmochemist Laurette Piani of the University of Lorraine in Vandœuvre-lès-Nancy, France, and colleagues analyzed meteorites known as enstatite chondrites. Thanks to many chemical similarities with Earth rocks, these relatively rare meteorites are widely thought to be good analogs of the dust and space rocks from the inner solar system that formed Earth’s building blocks, Piani says.

    Sign Up For the Latest from Science News

    Headlines and summaries of the latest Science News articles, delivered to your inbox

    She and her team measured the abundance of hydrogen in these meteorites — a proxy for how much H2O they could produce — and calculated that local interplanetary debris had the potential to deliver at least three times as much water as is found in all the oceans. The meteorites don’t contain water, Piani says. Rather, they house enough of the raw ingredients to create water when heated.
    In the meteorites, the team also found a close match to the type of water found in Earth’s mantle. A smattering of all water molecules on Earth contain a heavy variant of hydrogen known as deuterium. The ratio of deuterium to hydrogen in the enstatite chondrites lies within the range measured in Earth’s deep water. That similarity, the team argues, makes a strong case for local building blocks being the source of much of the planet’s water.
    “This work is something I wanted to do myself or had been waiting for someone to do,” says Lydia Hallis, a planetary scientist at the University of Glasgow in Scotland. In 2015, she led a team that measured the deuterium abundance in lava plumes that tap deep into Earth’s mantle (SN: 11/12/15). “I’m really happy that [the new data] sits within the region where our previous data from deep mantle samples is sitting.”
    Hallis and others stress that these new measurements are difficult. Once the meteorites hit the ground, they quickly absorb hydrogen from Earth’s environment. “They did a really good job of picking the right meteorites and making the right measurements,” she says. “This is pretty convincing that this hydrogen that’s measured is from the enstatite chondrites rather than from terrestrial contamination.”
    The enstatite chondrites could have also contributed a lot of water to the oceans as well — but they are not the full story. The deuterium-hydrogen ratio in ocean water, which is a bit higher than that of mantle water, is better matched to the ratio found in icy asteroids from the outer solar system. “We still need a bit of water coming from the outer solar system,” Piani says. So, while local materials may have delivered the bulk of Earth’s water, the oceans were likely topped off a bit later by collisions with remote space rocks. More

  • 138 Shares119 Views

    in Space & Astronomy

    Jupiter’s moons could keep each other warm by raising tidal waves

    It takes a certain amount of heat to keep an ocean wet. For Jupiter’s largest moons, a new analysis suggests a surprising source for some of that heat: each other.
    Three of the gas giant’s four largest moons, Ganymede, Callisto and Europa, are thought to harbor oceans of liquid water beneath their icy shells (SN: 5/14/18). The fourth, the volcanic moon Io, may contain an inner magma ocean (SN: 8/6/14).
    One of the primary explanations for how these small worlds stay warm enough to harbor liquid water or magma is gravitational kneading, or tidal forces, from their giant planetary host. Jupiter’s huge mass stretches and squishes the moons as they orbit, which creates friction and generates heat.
    But no studies had seriously considered how much heat the moons could get from gravitationally squishing each other.

    Sign Up For the Latest from Science News

    Headlines and summaries of the latest Science News articles, delivered to your inbox

    “Because [the moons are] so much smaller than Jupiter, you’d think basically the tides raised by Io on Europa are just so small that they’re not even worth thinking about,” says planetary scientist Hamish Hay of NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
    Together with planetary scientists Antony Trinh and Isamu Matsuyama, both of the University of Arizona in Tucson, Hay calculated the size of the tides that Jupiter’s moons would raise on each other’s oceans. The team reported the results July 19 in Geophysical Research Letters.
    The researchers found that the significance of the tides depends on how thick the ocean is. But with the right-sized ocean, neighboring moons could push and pull tidal waves on each other at the right frequency to build resonance. It’s a similar effect to pumping your legs on a swing, or synchronized footfalls making a bridge wobble, Hay says.
    “When you get into one of these resonances, those tidal waves start to get bigger,” he says. Those waves would then rush around the moon’s interior and generate heat through friction, the researchers calculated. If the conditions are right, heat from the gushing tidal waves could exceed heat from Jupiter.
    The effect was biggest between Io and Europa, the team found.
    “Basically everyone neglected these moon-moon effects,” says planetary scientist Cynthia Phillips of NASA’s Jet Propulsion Laboratory, who was not involved in the new work. “I was just astonished … at the amount of heating” that the moons may give each other, she says.
    The extra infusion of energy into Europa’s ocean could be good news for the possibility of alien life. Europa’s subsurface ocean is thought to be one of the best places in the solar system to look for extraterrestrial life (SN: 4/8/20). But anything living needs fuel, and the sun is too far away to be useful, Phillips says.
    “You have to find other sources of energy,” she says. “Any kind of frictional or heating energy is really exciting for life.” More

  • 88 Shares99 Views

    in Space & Astronomy

    ‘Exotic’ lightning crackles across Jupiter’s cloud tops

    Small, frequent lightning storms zip across Jupiter’s cloud tops. NASA’s Juno spacecraft spotted the flashes for the first time, scientists report August 5 in Nature.
    “It’s a very exotic thing that doesn’t exist on Earth,” says physicist Heidi Becker of NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
    Previous spacecraft have revealed high-energy “superbolts” on Jupiter. That lightning originates 50 to 65 kilometers below Jupiter’s cloud tops, where liquid water droplets form. Scientists think superbolts form like lightning on Earth does: Colliding ice crystals and water droplets charge each other up, then stretch the charge between them when they separate (SN: 6/25/20).
    Juno, which arrived at Jupiter in 2016, got much closer to the giant planet’s cloud tops than previous missions. Becker and her team turned the spacecraft’s navigation camera — which normally observes stars to track Juno’s position — on Jupiter’s nightside in February 2018. To the team’s surprise, the clouds crackled with electricity.
    Newly observed lightning showed up as bright dots (indicated with arrows) on Jupiter’s nightside, seen in this composite image from two of Juno’s cameras. The insets are pixelated representations of the events’ brightness (yellow is more bright; blue is less bright).H.N. Becker et al/Nature 2020
    Superbolts are up to 100,000 times as strong as these small flashes. But the cloud-top lightning is 10 times as frequent. Strangely, the smaller bolts appeared to come from just 18 kilometers below the cloud tops, where it’s too cold for liquid water to exist alone.
    Shallow lightning must have a different origin than the deeper lightning, Becker says. Perhaps ammonia in the upper cloud decks acts as antifreeze, creating droplets of ammonia and water combined. Juno has also seen evidence that violent storms in deeper cloud layers sometimes toss ice crystals high above where they’re normally found. When those crystals collide with the ammonia-water droplets, they may charge up and create lightning, Becker and her colleagues reason.
    Similar small lightning storms may happen on other planets, including exoplanets, Becker says (SN: 5/13/16). “Every time you have a new realization, it feeds into new theories that will be developed not only for our solar system but for other solar systems.” More

  • 125 Shares119 Views

    in Space & Astronomy

    The Perseverance rover caps off a month of Mars launches

    NASA’s Perseverance rover took off at 7:50 a.m. EDT on July 30 from Cape Canaveral, Fla., and is now on its way to Mars with a suite of instruments designed to search for ancient life. The launch is the third this month of spacecraft en route to the Red Planet.
    This is the 22nd spacecraft NASA has aimed at Mars (16 of those missions were successful). But Perseverance will be the first mission to cache rock samples from the Red Planet for a future mission to bring back to Earth.
    It will also be the first NASA mission in more than 40 years to directly search for life on Mars. The rover will land in a region called Jezero crater (SN: 7/28/20). That crater was once an ancient lake bed, and scientists think its rocks and sediments could preserve signs of life, if life was ever there (SN: 7/29/20). The spacecraft will take video and audio recordings of its own landing as it touches down — another first for a NASA Mars mission.
    “This mission has more cameras on it than any we’ve ever sent before,” said Lori Glaze, director of NASA’s Planetary Science Division, on July 30 during a news conference. “It’s going to feel like we’re actually there, riding along with Perseverance on the way down.”
    Perseverance, shown here in an artist’s illustration, will seek signs that Mars once hosted alien life.JPL-Caltech/NASA
    Mars launches tend to come in clumps thanks to Mars’ and Earth’s orbits. The planets line up on the same side of the sun every two years, so scientists have narrow windows to launch for the most efficient trip. All three of this year’s missions will arrive in February 2021.
    The other missions launched in July represent firsts for their respective countries. The United Arab Emirates’ first interplanetary mission, which carries an orbiter called the Hope Probe, launched from Japan on July 19. Hope will measure Mars’ weather, from daily temperature changes to the significance of dust in the planet’s atmosphere (SN: 7/14/20).

    Sign Up For the Latest from Science News

    Headlines and summaries of the latest Science News articles, delivered to your inbox

    Next up was China’s first Mars mission, Tianwen-1, which means “questions to heaven” and launched on July 23. China has previously sent spacecraft to orbit and land on the moon (SN: 1/3/19). And it is the first nation to send an orbiter, lander and rover all at once on its first attempt to reach Mars. “No planetary missions have ever been implemented in this way,” mission scientists wrote July 13 in Nature Astronomy. “If successful, it would signify a major technical breakthrough.”
    Tianwen-1’s lander and rover will touch down in Utopia Planitia in April 2021. Instruments on the rover and lander will test Mars’ soil composition and magnetic and gravitational fields and will probe Mars’ interior.
    Utopia Planitia is the same region where the first long-lived Mars lander, NASA’s Viking 1, touched down in 1976 (SN: 7/20/16). Viking was the first spacecraft to search for life on Mars, but its results were inconclusive. Perhaps with the rush of spacecraft this year, and the plans to bring red rocks home, scientists will finally learn whether Mars ever did — or does — host alien life. More

  • 138 Shares169 Views

    in Space & Astronomy

    To rehearse Perseverance’s mission, scientists pretended to be a Mars rover

    Megan Barrington watched the sun rise over the rocky outcrop. When light struck at exactly the right angle, she mounted a gizmo that looked like eye exam equipment on a tripod and aimed it at the spot. The goal: gather evidence that this windswept wilderness once teemed with life, and then beam the information to her colleagues back home.
    Soon, a version of that setup (minus Barrington) will be deployed on Mars. The state-of-the-art, zoomable, multispectral camera is part of the toolkit on NASA’s Perseverance rover (SN: 7/28/20). “That instrument is going to allow me to look at the mineralogy of Mars at Jezero crater,” the rover’s landing spot, says Barrington, a planetary scientist at Cornell University.
    The rover is scheduled to launch to Mars on July 30. A February role-playing exercise in the Nevada desert by Barrington and six colleagues was a kind of dress rehearsal for the rover’s various instruments. Another 150 team members around the world played the “Earth” team during those two weeks, sending commands from remote mission control and receiving data as it would appear coming from the real rover.
    “We’re not just simulating a Mars mission,” says engineer Raymond Francis of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., who organized and led the trip. “We’re simulating a specific Mars mission by presenting data … to the people who designed the instrument that will take that data. So the standard is high not to look like clowns.”

    Sign Up For the Latest from Science News

    Headlines and summaries of the latest Science News articles, delivered to your inbox

    Perseverance has the most demanding and ambitious to-do list of any rover yet: seek signs of past Martian life, prepare the way for future human missions and collect at least 20 samples of Martian rock for eventual return to Earth. And that’s just in its first two years. For contrast, Curiosity rover has drilled a few dozen holes over eight years on Mars, and didn’t store any of those samples for later (SN: 7/7/18, p. 8).
    The dress rehearsal in the desert will help ensure that when Perseverance lands on the Red Planet in February 2021, its handlers on Earth can get straight to the science.
    “We don’t want to get there and learn how to explore Mars while on Mars,” Francis says. “We want [team members] to be ready when the rover hits the ground.”
    Water marks the spot
    The first order of business was to find the right spot for the dry run. “We had to pick a site that kind of looked like Mars,” Francis says. “The parking lot would not do.” The team wanted the site to look as Mars-like as possible, no factories, footprints or foliage to break the illusion.
    An ideal site would have geology that echoed Jezero crater, which is thought to be the remnants of an ancient lakebed and river delta (SN: 11/19/18). It also had to be within a few hours’ drive of JPL, and not totally off the grid — the rover team slept in hotels, ate dinner in restaurants and had reliable Wi-Fi to send data to the Earth team every night.
    The final requirement was that it be someplace the Earth team hadn’t seen before. If mission control members recognized the site, they could bias their findings with what they already knew.
    Engineer and team leader Raymond Francis gets up close with the rocks to make a measurement.JPL-Caltech/NASA
    “Most of the popular Mars analogs are already well known to the Mars community,” Francis says. “So we had to be a little sneaky.”
    Previous exercises, in November 2017 and February 2019, were run in the Mojave Desert in California. For 2020, the rover team headed to Walker Lake in western Nevada. The lake’s water has been receding for a thousand years, so there are spots near the ancient shoreline where the present-day lake is invisible.
    Walker Lake’s rocks preserved a cornucopia of biological signals for the ground team to discover: fossilized fish bones and shells of tiny shrimplike crustaceans called ostracods, which are not expected on Mars; and microbial fossils called stromatolites, which could plausibly be found in Jezero crater (SN: 10/17/18).
    Toolkit
    Francis and his team brought handheld versions of almost all the rover’s instruments to gather whatever data the Earth team requested. They had a drill, handheld spectrometers, lasers, a ground-penetrating radar that they transported in a jogging stroller, plus several elaborate camera setups to represent the rover’s navigation, hazard avoidance and zoomable 3-D science cameras.
    Perhaps the most important piece of equipment was the broom used for sweeping away footprints. It became a running joke, Francis says: “We’ve got all this equipment, a multibillion-dollar mission, and it’s all hinging on this 99-cent broom.”
    Almost everything went smoothly. But a few days into the mission, Barrington’s zoomable camera had “a major malfunction,” she says. She framed her shot, and…. nothing happened. The camera wasn’t getting any power, she realized. “I took it apart and rewired many pieces, to no avail,” she says.
    She and her teammates finally realized one of the power adapters had completely blown. She had to drive two hours to the nearest city to get a new one.
    Of course, driving into town to get a new part won’t be an option on Mars. The real camera, called Mastcam-Z, has been through weeks of rigorous testing and calibration, and is probably up to the task. But “we all go into missions knowing that sometimes irreversible mistakes occur,” Barrington admits. “All we can do at that point is use the instruments to the fullest capacity of which they are capable of operating.”
    Planetary scientist Megan Barrington adjusts her instrument, a multispectral, zoomable camera standing in for Perseverance’s Mastcam-Z.JPL-Caltech/NASA
    Signs of life, big and small
    There was one major giveaway that the team was actually on Earth. “This is very much middle-of-nowhere desert, which is good,” Francis says. But the rover site was mere steps from a U.S. Department of Defense munitions facility, one of the largest in the world.
    “It was really something to behold,” Barrington says. “They had hundreds of bunkers lined up in rows as far as you could see…. All of that was one very crooked metal fence away from us.”
    More than once, military police showed up to check the team’s credentials. “I had to approach them and say, hello, people with the guns, I need you to stop walking now,” Francis says. “We’re running a Mars rover simulation and we don’t want you to put your footprints in this sand.”
    Despite Francis and colleagues’ best efforts, the bunkers showed up in a few photos. The ground team gamely ignored them, apart from a few jokes about SpaceX founder Elon Musk building a Martian city.
    By the end of the two-week exercise, the remote science team reviewing the data had noticed the ostracods and fishbones, and started exploring the stromatolites. “They were doing a good job of finding the biomarkers,” Francis says, who now has hope that “if Mars is hiding stromatolites, maybe we’ll see them.”
    Coming home to quarantine
    The field trip ended on February 27, just as awareness of the novel coronavirus SARS-CoV-2 was rising in the United States. By March 15, JPL told employees to work from home. “We only had a few days together before we were all on remote work,” Francis says.
    The pandemic has already contributed to the delay of the launch of the European and Russian ExoMars rover, which was also supposed to launch in July (SN: 3/12/20).  If Perseverance misses the late July to early August launch window, the rover can’t head to Mars until 2022.
    If the pandemic is still an issue by the time the rover lands in February, Francis doesn’t know what the team will do. “But,” he says, “the good news is the mission is designed for remote operations.” More

  • 138 Shares149 Views

    in Space & Astronomy

    NASA’s Perseverance rover will seek signs of past life on Mars

    NASA’s next rover is a connoisseur of Martian rocks. The main job of the Perseverance rover, set to launch between July 20 and August 11, is to pick out rocks that might preserve signs of past life and store the samples for a future mission back to Earth.
    “We’re giving a gift to the future,” says planetary scientist Adrian Brown, who works at NASA Headquarters in Washington, D.C.
    Most of the rover’s seven sets of scientific instruments work in service of that goal, including zoomable cameras to pick out the best rocks from afar and lasers and spectrometers to identify a rock’s makeup. After the rover lands in February 2021, it’s capable of collecting and storing 20 samples within the first Martian year (about two Earth years). The NASA team plans to collect at least 30 samples over the whole mission, says planetary scientist Katie Stack Morgan of NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
    Fortunately, Perseverance is headed to a spot that should be full of collection-worthy rocks. The landing site in Jezero crater, just north of the Martian equator, contains an ancient river delta that looks like it once carried water and silt into a long-lived lake.

    Sign Up For the Latest from Science News

    Headlines and summaries of the latest Science News articles, delivered to your inbox

    “We can already predict which parts of that delta might give us the highest return for possible biosignatures,” Stack Morgan says. The crater has a “bathtub ring” of carbonates, minerals that settle in shallow, warm waters that are especially good at preserving signs of life. “That makes Jezero special,” she says.
    But Perseverance is more than a rock collector. The rover will probe the ground beneath its wheels, fly a helicopter, track the weather and test tech for turning Martian air into rocket fuel. Every part of the rover has a job to do.

    RIMFAX
    RIMFAX, or Radar Imager for Mars’ Subsurface Experiment, will use radio waves to probe the ground under the rover’s wheels. The instrument will take a measurement every 10 centimeters along the rover’s track and should be able to sense 10 meters deep, depending on what’s down there. The InSight lander, currently on Mars, has a seismometer that listens for Marsquakes, but a ground-penetrating radar to understand the Martian interior is a first.

    MOXIE
    Human explorers will need oxygen on Mars, but not just for breathing, says former astronaut Jeffrey Hoffman. “It’s for the rocket,” says Hoffman, now an engineer at MIT. To take off from the Martian surface and return home, astronauts will need liquid oxygen rocket fuel. Bringing all that fuel from Earth is not an option.
    To demonstrate how to make fuel from scratch, MOXIE, or Mars Oxygen In-Situ Resource Utilization Experiment, will pull carbon dioxide out of the Martian atmosphere and convert it to oxygen. MOXIE will produce about 10 grams of oxygen per hour, which is only about 0.5 percent of what’s needed to make enough fuel for a human mission over the 26 months between launch windows. But the effort will teach engineers on Earth how to scale up the technology.

    Mastcam-Z
    Set atop Perseverance’s neck, Mastcam-Z, the rover’s main set of eyes, can swivel 360 degrees laterally and 180 degrees up and down to view the surrounding landscape. Like its predecessor on the Curiosity rover, the camera will take color, 3-D and panoramic images to help scientists understand the terrain and the mineralogy of the surrounding rocks. Mastcam-Z can also zoom in on distant features — a first for a Mars rover.

    SuperCam
    How can Perseverance look for signs of ancient microbes in rocks too far away to touch? Enter SuperCam, a laser spectrometer mounted on the rover’s head. SuperCam will shoot rocks with a laser from more than seven meters away, vaporizing a tiny bit of the minerals. Researchers will then analyze the vapor to help figure out what the rocks are made of, without having to drive the rover down steep slopes or up rugged crags. The laser will also measure properties of the Martian atmosphere and dust to refine weather models.

    MEDA
    MEDA, or Mars Environmental Dynamics Analyzer, is the rover’s weather station. Six instruments distributed across the neck, body and interior will measure air temperature, air pressure, humidity, radiation and wind speed and direction. The tools will also analyze the physical characteristics of the all-important Mars dust. Scientists hope to use the information from these sensors to better predict Mars weather.

    PIXL, SHERLOC and WATSON
    Geologists never go into the field without a hand lens. Likewise, Perseverance will be prepared with three arm-mounted magnifying instruments. PIXL, the Planetary Instrument for X-ray Lithochemistry, will have a camera that can resolve grains of Martian rock and dirt to scales smaller than a millimeter. It will also detect the chemical makeup of those rocks by zapping them with X-rays and measuring the wavelength of light the rocks emit in response. SHERLOC, or Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals, will take similar measurements using an ultraviolet laser. WATSON, the Wide Angle Topographic Sensor for Operations and Engineering, will take pictures with a resolution of 30 micro­meters to put the chemistry in context. The instruments will seek signs of ancient microbes preserved in Martian rocks and soil, and help scientists decide which rocks to store for a future mission to return to Earth.
    Ingenuity
    This helicopter will be a test case for future reconnaissance missions to help the rover see further on Mars.JPL-Caltech/NASA
    Perseverance will also carry a stowaway folded up origami-style in a protective shield the size of a pizza box: a helicopter called Ingenuity. At a smooth, flat spot, Ingenuity will drop to the ground and unfold, then take about five flights in 30 Martian days. These flights are mainly to show that the copter can get enough lift in the thin Martian atmosphere. If Ingenuity is successful, future helicopters might help run reconnaissance for rovers. “There’s always a question with the rover, what’s over that cliff? What’s over that rise?” says planetary scientist Briony Horgan of Purdue University in West Lafayette, Ind. “If you have a helicopter, you can see those things ahead of time.”

    Trustworthy journalism comes at a price.

    Scientists and journalists share a core belief in questioning, observing and verifying to reach the truth. Science News reports on crucial research and discovery across science disciplines. We need your financial support to make it happen – every contribution makes a difference.

    Subscribe or Donate Now More