Fleets of radar satellites are measuring movements on Earth like never before. East Africa has been called the cradle of humanity. But the geologically active region has also given birth to dozens of volcanoes. Few have been monitored for warnings of a potential eruption, and until recently, most were believed to be dormant. Then, Juliet Biggs decided to take a closer look—or rather, a farther look. Biggs, a geophysicist at the University of Bristol, uses a technique called interferometric synthetic aperture radar (InSAR) to detect tiny movements of Earth's surface from space. In a series of studies, she and her co-authors analyzed satellite data on the East African volcanoes. According to their latest results, which were published last month, 14 have been imperceptibly growing or shrinking in the past 5 years—a clue that magma or water is moving underground and that the volcanoes are not completely asleep. “It's really changed the way these volcanoes are viewed, from something that's kind of dormant to really very active systems,” Biggs says. After data showed that the Corbetti volcano, which abuts the fast-growing city of Hawassa, Ethiopia, is inflating steadily at a rate of 6.6 centimeters per year, Biggs's Ethiopian colleagues included it in the country's geological hazard monitoring network. No other technology could produce such a comprehensive survey. Individual GPS stations can track surface movements of less than 1 millimeter, but InSAR can measure changes almost as subtle across a swath hundreds of kilometers wide. That has made it a vital tool for earth scientists studying the heaves and sighs of our restive planet. “We tend to think of the ground as this solid platform,” Biggs says, “and actually, it's really not.” With InSAR, scientists are tracking how ice streams flow, how faults slip in earthquakes, and how the ground moves as fluids are pumped in or out. “Everywhere you look on Earth, you see something new,” says Paul Rosen, an InSAR pioneer at NASA's Jet Propulsion Laboratory (JPL). “It's a little bit like kids in a candy store.” And the flood of InSAR data is growing fast. Since 2018, the number of civil and commercial SAR satellites in orbit has more than doubled. And at least a dozen more are set to launch this year, which would bring the total to more than 60. With the help of computing advances that make data processing easier, the satellite fleets may soon be able to detect daily or even hourly surface changes at just about every patch of ground on Earth. As the technology grows more powerful and ubiquitous, InSAR is spreading beyond the geosciences. With InSAR data, railroads are monitoring the condition of their tracks and cities are monitoring shifts in buildings caused by construction. “It's popping up everywhere,” says Dáire Boyle, who follows trends in the space industry for Evenflow, a consulting firm in Brussels. Analysts value the SAR market at roughly $4 billion, and expect that figure to nearly double over the next 5 years. Many believe InSAR will eventually underpin our daily lives. From measuring the water stored in mountain snowpacks to enabling quick responses to natural disasters, InSAR data will prove invaluable to governments and industries, says Cathleen Jones, a science team leader for NISAR, an upcoming joint SAR mission from NASA and the Indian Space Research Organisation (ISRO). “I want it to become so socially relevant that they can't go back to not having this data.” SYNTHETIC APERTURE RADAR , the “SAR” on which InSAR depends, originated in the 1950s as a tool for airborne military reconnaissance. Like traditional radar, SAR instruments captured images of the planet by sending out microwave pulses and recording the echoes. And like a traditional radar, the instruments could penetrate clouds and worked equally well at night. A key difference was the “synthetic” aspect of SAR. Larger radar antennas, like larger apertures on a camera, collect more of the echoes and enable sharper pictures. But building a single antenna large enough to take a high-resolution image isn't practical. Researchers realized they could instead create an artificially large aperture by combining the signals received on a much smaller antenna as it moved through space. Today, SAR satellites with antennas just a few meters across can produce images with pixel resolutions as sharp as half a meter—better than many satellite-borne cameras. SAR images, on their own, suffice for many types of surveillance, from counterterrorism to tracking oil spills in the ocean. But InSAR goes further, by looking for differences between multiple SAR images. The technique takes advantage of phase information in the returning microwaves—in other words, where a signal is in its sinusoidal path when it hits the antenna. Any phase difference in the signal between SAR images taken from the same position at different times means the round-trip distance has changed, and can reveal surface movements down to a few millimeters. “There's nothing else that compares to it,” says Michelle Sneed, a hydrologist at the U.S. Geological Survey. “I'm still amazed by it after a couple of decades.” The 1978 launch of Seasat, NASA's first ocean-observing satellite, provided data for early InSAR efforts. Seasat operated for just 105 days before a power failure brought the mission to an untimely end. But in that time, it collected repeat images of California's Imperial Valley taken over the course of 12 days. Scientists at JPL later compared those images using InSAR to show the subtle swelling of fields as they soaked up irrigation water. “It is not hard to think of numerous applications for the type of instrument demonstrated,” the authors wrote in a 1989 paper. And they were right. ![Figure] CREDITS: (GRAPHIC) N. DESAI/ SCIENCE ; (DATA) ESA; WMO; GUNTER'S SPACE PAGE A classic InSAR study came in 1993, when a team of scientists in France used data from the SAR-enabled European Remote Sensing satellite to study a powerful earthquake that rocked Landers, California, the year before. By analyzing images taken before and after the quake, they calculated that the fault had slipped by up to 6 meters, which agreed with detailed field observations. The InSAR data also revealed how the ground buckled for kilometers around the fault—illustrating the full effects of the temblor at an unprecedented scale. The paper inspired scientists like Sneed, who went on to use InSAR to study how groundwater extraction causes the ground to sink. During a drought in California's San Joaquin Valley in the late 2000s, she and her colleagues discovered that the surface was subsiding as fast as 27 centimeters per year in places where farmers pumped the most groundwater. Irrigation canals were sagging as a result of uneven sinking, impeding water flow. “It's a really expensive problem,” Sneed says. (Another recent InSAR study linked specific water-intensive crops—notably corn, cotton, and soy—to increased subsidence.) Glaciologists adopted the technology, too. As a young researcher at JPL in the 1990s, Ian Joughin used InSAR—which tracks both vertical and horizontal movements—to measure the speed of polar ice streams. Some scientists thought flow rates would be relatively immune to climate change. But, sadly for the world, InSAR studies by Joughin and others proved those predictions wrong. “Especially in the early 2000s, we just saw all kinds of glaciers double their speed,” says Joughin, who now studies the fate of polar ice sheets and their contribution to sea-level rise at the University of Washington, Seattle. By the 2000s, many earth scientists were using InSAR—and grappling with its limitations. There were few SAR satellites in orbit, and they tended to switch between instruments or imaging modes to accommodate different users' needs, making the data hard to use for InSAR. The early missions collected the repeat images needed for InSAR only about once a month, and researchers often had to correct for their wobbly orbits. That meant that although scientists could study an event after it happened, they could rarely watch it unfold in real time. Leaders at the European Space Agency (ESA) were convinced there was a better way. MALCOLM DAVIDSON REMEMBERS the excitement and anxiety he felt on 3 April 2014, the day the first Sentinel-1 satellite launched. “All your life goes into a few minutes,” says Davidson, mission scientist for ESA's flagship SAR program. He also remembers the relief when the satellite safely reached orbit, and the awe that came over him when he saw its first image, of ocean swells. “It was very convincing that the mission was going to do great things,” he says. With Sentinel-1, the plan was simple: “We cut out all the experiments, and we said, ‘Look, this is a mapping machine.’” He and his colleagues chose a primary imaging mode to use over land—surveying a 250-kilometer swath at a resolution of 5 meters by 20 meters—that they hoped would satisfy most researchers, and made sure the orbits would overlap precisely, so all the data would be suitable for InSAR. The first satellite, Sentinel-1a, retraced its path every 12 days. Then, in 2016, ESA launched a clone that made repeat images available about every 6 days for many places on Earth. SAR missions like Italy's COSMO-SkyMed and Germany's TerraSAR-X also support InSAR and can achieve even higher resolutions. But they do not distribute data freely like Sentinel, which many credit for driving a transition from opportunistic experiments to what Davidson sees as “a more operational view of the world.” With Sentinel-1 data, Norway created a national deformation map that has helped identify rockslide hazards and revealed that parts of Oslo's main train station were sinking. Water managers in California rely on the data to track groundwater use and subsidence. And in Belgium, it is used to monitor the structural integrity of bridges. “It can all be done remotely now, saving time, saving money,” Boyle says. The large and growing body of InSAR data has also revealed small surface movements that were previously hidden by noise. As radar signals pass through the atmosphere, they slow down by an amount that depends on the weather, producing variability that can swamp tiny but important displacements. Thanks to long-term records from missions like Sentinel, researchers can now tease information from the noise, for example, helping them track movements of just a few millimeters per year in Earth's crust—enough to strain faults and eventually cause earthquakes. Such efforts would not have been possible without huge gains in computing power. In the 1990s, stacking a single pair of SAR images could take days, Sneed says, and interpreting the results could take much longer. Now, researchers can process hundreds of images overnight, and they increasingly rely on artificial intelligence (AI) algorithms to make sense of the data. In one recent test, an AI algorithm was tasked with identifying small fault movements known as slow earthquakes. It correctly found simulated and historical events, including ones that had eluded human InSAR experts, says Bertrand Rouet-Leduc, a geophysicist at Los Alamos National Laboratory who presented preliminary results in December 2020 at the annual meeting of the American Geophysical Union. Rouet-Leduc and his team now plan to monitor faults around the world using the same approach. He says it's mostly a matter of exploiting the vast quantity of data that “sits on servers without being looked at,” because it's simply too much for scientists to tackle. The researchers hope they will be able to answer questions like when and why slow earthquakes happen, and whether they can trigger big, damaging events by increasing stress on other parts of a fault. Commercial users often lack the expertise to process InSAR data, so hundreds of companies have sprung up to help. One, Dares Technology, monitors the ground for the construction, mining, and oil and gas industries. By tracking surface changes as fluids are injected or extracted from an oil reservoir, for example, Dares can help companies estimate pumping efficiency and prevent dangerous well failures. In the beginning, convincing clients that InSAR data were useful and trustworthy was difficult, says Dares CEO Javier Duro. Now, he says, “Everybody wants to include InSAR in their operations.” Duro is particularly interested in detecting precursors to accidents, for example, by looking for signs of instability in the walls of open-pit mines or in the dams used to store mine tailings. The company usually sends out several alerts per month to clients, who can take actions to avoid disasters. “Typically, InSAR data have been used for back analysis,” Duro says. “Our mission is to focus on the present and the future, and try to predict what could happen.” THE SURGE IN SATELLITES promises to bring yet another InSAR revolution. Italy, Japan, Argentina, and China all plan to launch additional SAR satellites soon, and NISAR, the NASA-ISRO mission, will take flight in late 2022 or early 2023. NISAR will image Earth's full land surface every 6 days, on average, says Rosen, the mission's project scientist. Its two radar sensors will help researchers track many things, including crop growth and changes in woody biomass—crucial for understanding the climate system. With a better view of Antarctica than other missions, NISAR can also monitor changes in ice. Taken together, Sentinel-1, NISAR, and the other civil satellites will image most places on Earth at least every 12 hours, Rosen says. But the temporal resolution of InSAR will remain constrained by the revisit rate of the individual missions, because the technique can't be done with imagery from different missions. However, private companies with large constellations of microsatellites hope to vault the field into yet another realm, by radically increasing revisit frequencies. On 24 January, a SpaceX Falcon 9 rocket blasted off from Cape Canaveral, Florida, carrying three satellites, each about the size of a minifridge and weighing less than 100 kilograms, from Iceye. The Finnish SAR startup has raised more than $150 million toward its audacious goal of imaging every square meter of Earth every hour. The launch brought Iceye's commercial constellation to six, giving it an early lead over rival companies such as Capella Space—which had two satellites on the same rocket—and Umbra, both based in California. Iceye plans to add at least eight more satellites this year, allowing it to revisit most of the globe once a day. “That is groundbreaking,” says Pekka Laurila, who co-founded Iceye as an undergraduate at Aalto University and now serves as the company's chief strategy officer. Ultimately, Iceye hopes to assemble a constellation of as many as 100 satellites as it approaches its hourly monitoring objective. That would open up new applications, like tracking how buildings and dams expand during the heat of the day and contract at night—a clue to their structural integrity. Already, Iceye data have been used to guide ships through Arctic sea ice and to track illegal fishing vessels. “If you can work closer to real time, you can actually do something about it,” Laurila says. So far, though, Iceye has focused on flood monitoring, which can guide disaster response efforts. In fact, the company provided some of the first images of Grand Bahama after Hurricane Dorian devastated the island in 2019, Laurila says. Precise flood data are also valuable to insurers, who can use them to trigger automatic insurance payouts after an event instead of processing claims and sending out inspectors. Until now, Iceye has tracked floods using regular SAR data, but it hopes to start to apply InSAR as it increases its revisit frequencies, because the technique can measure the height and extent of inundation much more precisely. And that's just the beginning of what Laurila hopes Iceye will do. His ultimate goal is to build a “new layer of digital infrastructure” that will provide a “real-time, always-available, objective view on the world,” he says. He believes that, like modern GPS, reliable SAR and InSAR data will support myriad applications, many of which have yet to be imagined. “Nobody thought of your Uber and pizza delivery when they thought of GPS,” Laurila says. If Iceye and its peers succeed, they will expose the shifts and shudders of the planet, day in and day out. They will spy tilting buildings and slumping slopes, and they will witness the growth of crops and the flow of commodities around the world. If space-based imagery often portrays Earth as quiet and still, InSAR reveals the true restlessness of our living planet. : pending:yes
Last week, NASA's $2.7 billion Perseverance rover made a picture-perfect landing on the floor of Mars's Jezero crater, which scientists believe was filled to the brim with water 3.8 billion years ago. Two kilometers away looms the rover's primary target: a fossilized river delta, created as muddy water spilled into the crater—ideal for preserving signs of life. But before Perseverance starts the long climb up into the delta, to drill samples that will eventually be returned to Earth, it will examine the rocks beneath its six aluminum wheels. The rover landed near outcrops of rock layers that may have originally been laid down before and after the lake and the delta. The NASA team will probe them for clues to the nature and timing of the brief period when water flowed—and life might have flourished. Even the first images returned to Earth, grainy and taken from the underneath the rover, left the team elated, says Katie Stack Morgan, the mission's deputy project scientist at NASA's Jet Propulsion Laboratory (JPL). “We have enough for the scientists to really sink their teeth into.” The rover's arrival at Mars was filled with nail-biting drama, even as the precise, autonomous descent unfolded like clockwork. After the spacecraft plunged by parachute through the thin air, a rocket-propelled hovercraft took over, seeking a boulder-free spot before lowering the rover from nylon cords. The final moments, captured in breathtaking detail by cameras below the hovercraft, show the rover landing in a cloud of dust. “We did have a pretty clean run,” says Allen Chen, head of the rover's landing team at JPL, in a dry understatement. “It did what it had to do.” The touchdown marks NASA's ninth successful landing on the martian surface out of 10 tries. ![Figure] GRAPHIC: C. BICKEL/ SCIENCE After 3 days, the rover had executed 5000 commands and scientific instruments were certifying their health, says Jessica Samuels, an engineer and mission manager at JPL. “Everything is coming back exactly how we want it to.” The rover raised its camera mast 2 meters above the surface to capture a panorama of its surroundings. After several days updating software, the team plans to wiggle the rover's wheels and conduct a short test drive. The rover will also extend its five-jointed, 2-meter-long robotic arm, which carries the rover's coring drill and several more cameras, and put it through some calisthenics. A second robotic arm, designed to manipulate a cache of dust and rock samples inside the rover, will be run through its paces. Stored in 43 ultraclean tubes, those samples represent the start of a multibillion-dollar, multinational effort to collect martian rocks and return them for analysis on Earth; two follow-up missions to retrieve the samples are planned for later this decade ( Science , 22 November 2019, p. ). Within its first 2 years, the rover is expected to fill nearly half the tubes on its trek of more than 10 kilometers to the crater's rim. The rest will be filled in an extended mission, as the rover trundles beyond the crater to ancient highlands thought to have once held geothermal springs. Perseverance's primary mission is to search for evidence of past life, captured in the delta mudstones and other rocks likely to preserve organic molecules—or even fossilized life. But interpreting this evidence will also require a better understanding of Mars's climatic past, from clues that can be collected right away by the rover. The first opportunity to drill a sample could come within a few months, on the flat, pebble-strewn terrain where Perseverance landed. Some scientists believe these rocks are from an ancient lava flow that erupted long after the lake disappeared, arguing that they look the way Hawaiian flows might if bombarded by meteorites and whipped by winds for several billion years. But when Perseverance's predecessor, the Curiosity rover, explored similar rocks in Gale crater and its ancient lake, most of what scientists had thought were lava fields turned out to be sedimentary rocks: ground up volcanic bits ferried by water and deposited in layers, presumably in the vanished lake. The early pictures from Perseverance are difficult to interpret: Rocks riddled with holes could be pumice, porous from gas escaping from cooling lava, or they could be sedimentary rocks, perforated over time by water. Bigger boulders in the distance look like ancient volcanic rocks: dark and coated by a light-colored dust. Fortunately, Perseverance's scientific instruments are designed to pin down the rocks' origin. Cameras on the mast could spy distinctive angular striped layers, called cross-bedding, that only form when deposited as sediments. A camera mounted on the end of the rover's robotic arm for microscopic views could capture the grain of minerals: Sedimentary rocks, for example, are typically rounded by their watery travels. Two other instruments on the arm will fire x-rays and ultraviolet laser light at rock samples, provoking reactions that could reveal chemical fingerprints of volcanic or sedimentary rocks. It's a crucial distinction. If the rocks are volcanic—either lava deposits or, more likely, ash from a distant eruption—they'll contain trace radioactive elements that decay at a certain rate, so when samples are returned to Earth, lab scientists could date the eruption and put a bound on the age of the lake. Any date will also help pin down the highly uncertain overall martian timeline, currently dated by counting the number of craters on a given terrain. (Older surfaces are pocked with more craters.) Sampling such a volcanic rock would “provide a critical anchor to the timing of events we are looking at,” says Ken Farley, the mission's project scientist and a geologist at the California Institute of Technology. The rover's initial path is likely to cross another intriguing target just 250 meters away on the crater floor: outcrops that, from orbit, appear rich in both olivine, a volcanic mineral, and carbonates, which can form when olivine is exposed to water and carbon dioxide. If this layer is volcanic ash from an eruption that preceded the Jezero lake, radioactive dates from it and the potential volcanic layer deposited on the lakebed should bracket the lake's existence in time. Moreover, isotopes of oxygen in the carbonates could reveal the temperature of the water that formed the mineral; balmy water would suggest Mars was once warm and wet for millions of years at a time, whereas water near freezing would argue for sporadic bursts of warmth. The carbonate might even contain gas bubbles—samples of the ancient martian atmosphere, which could allow scientists to see whether it held methane or other greenhouse gases that would have warmed early Mars. “That obviously would be game changing,” says Timothy Goudge, a planetary scientist at the University of Texas, Austin, who led the team that made the case for Jezero as a landing site. There will be no drilling at the landing site itself. But there will be flying. After the monthlong commissioning phase is over, the team will find a nearby, flat spot to loose the 1.8-kilogram Ingenuity helicopter, which survived the landing attached to the rover's belly. With a fuselage the size of a tissue box, Ingenuity is a technology demonstration, a bid to fly a rotor-powered vehicle on another planet for the first time. After being dropped to the surface, the helicopter will furiously spin its rotors to ascend 3 meters in the air for 20 seconds. Four additional, higher flights could follow, over a total of 30 days, says MiMi Aung, Ingenuity's project manager at JPL. On later flights the helicopter could collect reconnaissance images for terrain off the rover's main path. “It will be truly a Wright brothers moment,” Aung says, “but on another planet.” : pending:yes : http://www.sciencemag.org/content/366/6468/932
Update: Perseverance is safe on the surface of Mars! The headline has been updated to reflect the news. There will be one more robot on Mars tomorrow afternoon. The Perseverance rover will touch down just before 1:00 PM Pacific, beginning a major new expedition to the planet and kicking off a number of experiments -- from a search for traces of life to the long-awaited Martian helicopter. Here's what you can expect from Perseverance tomorrow and over the next few years.
NASA's Perseverance rover has sent back astonishing video footage of its 18 February landing on Mars. These videos give us the most intimate look ever at the process of setting a spacecraft down on the Martian surface. During the landing, five cameras took videos: two on the back of the capsule holding the rover, one on the sky crane that acted as a jet pack to lower the rover its final 2000 metres or so to the surface and two on the rover itself. The videos show the parachute opening to slow down the spacecraft, and then the heat shield dropping to the surface of Mars once Perseverance is moving slow enough not to need it anymore. "You can get a sense really of how violent that parachute deploy and inflation are," said Al Chen, a Perseverance engineer at NASA's Jet Propulsion Laboratory (JPL) in California, during a press conference.
The helicopter sent to Mars by NASA to explore the Red Planet from the sky has'phoned home' and is working great, according to the space agency. Named Ingenuity, it rode to Mars strapped to the belly of the car-sized Perseverance rover that will trundle along the Jezero crater in search of ancient alien life. NASA mission control in Southern California received the first status report from Ingenuity late on Friday via the space-based Mars Reconnaissance Orbiter. Ingenuity will remain attached the belly of Perseverance for between 30 and 60 days before it detaches and makes its maiden flight - assuming it survives the brutal average -90C overnight temperatures found on the Red Planet. NASA shared an exciting image shot by the sky crane that shows Perseverance, nicknamed Perky, slung beneath and attached to mechanical bridals – moments before making landfall. The downlink confirmed that the helicopter, and an electrical box on the rover that routes and stores communications with Earth, were both performing as expected.
This week, Americans celebrated the successful delivery of NASA's Perseverance rover to its destination on the Martian surface, marking the dawn of a new era of interplanetary exploration. However, when it comes to searching the solar system around us, the US has not always led from the front. During the Reagan administration, for example, the agency saw its budget pared down in favor of building up arms ahead of an anticipated Cold War faceoff with the Soviet Union, as we see in this excerpt from David W Brown's latest work, The Mission. Excerpted from the book THE MISSION: or: How a Disciple of Carl Sagan, an Ex-Motocross Racer, a Texas Tea Party Congressman, the World's Worst Typewriter Saleswoman, California Mountain People, and an Anonymous NASA Functionary Went to War with Mars, Survived an Insurgency at Saturn, Traded Blows with Washington, and Stole a Ride on an Alabama Moon Rocket to Send a Space Robot to Jupiter in Search of the Second Garden of Eden at the Bottom of an Alien Ocean Inside of an Ice World Called Europa (A True Story) 2021 by David W. Brown. For planetary scientists, the Jimmy Carter–Ronald Reagan years were in retrospect like the Dark Ages, and they, the monks tending in enclaves to the embers of civilization.
Fox News Flash top headlines are here. Check out what's clicking on Foxnews.com. NASA's Perseverance team has already begun its work from Mars' surface and released incredible images on Friday taken from the rover. In a news conference, experts said they could only hope the photographs from their mission might be able to contribute to already iconic images from years of space exploration. "And, I'm happy to say that I'm hopeful that we can contribute with this," NASA Jet Propulsion Laboratory (JPL) Mars 2020 Chief Engineer Adam Steltzner stated. In the first image revealed, Perseverance is shown approaching its landing site in Mars' Jezero Crater and hanging just 6.5 feet over the ground.
The image you see above was taken just moments before NASA's Perseverance rover successfully landed on the surface of Mars, and it's just the first of many high-resolution photos to come. NASA pulled the image from a video of the rover's descent that is in the process of being transmitted to Earth. "This shot from a camera on my'jetpack' captures me in midair, just before my wheels touched down," the rover's official Twitter account said. NASA's Curiosity rover and Mars Reconnaissance Orbiter caught Perseverance's trip to the surface as well. Every picture tells a story.
NASA says its Perseverance rover is in'great shape' after successfully landing on the surface of Mars last night after a 239 million-mile journey. The landmark landing shortly before 4pm ET (9pm GMT) was watched live by millions as NASA live streamed the process to millions of eager viewers. The $2.2billion car-sized rover guided itself to a patch of smooth terrain in Jezero, a 28-mile wide and 820ft-deep crater which was home to a Martian lake 3.5 billion years ago. Perseverance, nicknamed Percy, survived the dreaded'seven minutes of terror' which saw it endure temperatures in excess of 2,000 F as it entered the Martian atmosphere at more than 12,000mph. Perseverance beamed back its first image of the crater moments after NASA established radio contact with the rover, leading to raucous applause and joyous scenes at NASA's Californian mission control. Flight controller Swati Mohan announced to relieved colleagues: 'Touchdown confirmed! Perseverance safely on the surface of Mars, ready to begin seeking signs of past life.' 'The good news is the spacecraft, I think, is in great shape,' said Matt Wallace, Deputy Project Manager of Mars 2020. Perseverance will spend the next two Earth years scouring for signs of life in the crater and will perform a host of experiments.
Los Angeles – NASA's science rover Perseverance, the most advanced astrobiology laboratory ever sent to another planet, streaked through the Martian atmosphere on Thursday and landed safely on the floor of a vast crater, its first stop on a search for traces of ancient microbial life on the Red Planet. Mission managers at the U.S. space agency's Jet Propulsion Laboratory near Los Angeles burst into applause, cheers and fist-bumps as radio beacons signaled that the six-wheeled rover had survived its perilous descent and arrived within its target zone inside Jezero Crater, site of a long-vanished Martian lake bed. "Touchdown confirmed," Swati Mohan, the lead guidance and operations specialist announced from the control room. The robotic vehicle sailed through space for nearly seven months, covering 293 million miles (472 million km) before piercing the Martian atmosphere at 12,000 miles per hour (19,000 km per hour) to begin its descent to the planet's surface. Moments after touchdown, Perseverance beamed back its first black-and-white images from the Martian surface, one of them showing the rover's shadow cast on the desolate, rocky landing site.