![]() ![]() Over the next six months, several more rocks on the crater floor revealed igneous texture. The texture of the rock, Stack Morgan says, was “a textbook igneous volcanic rock texture.” It looked like volcanic lava flows. But from the first real science drilling near the landing location, researchers back on Earth realized what they had found. JPL-CALTECH/NASA, MSSSįor the first several months after the landing, the Mars 2020 mission team tested the rover’s movements and instruments, slowly, carefully. Stack Morgan is deputy project scientist for Perseverance.Ĭloseup images of an abraded rock from the floor of the Jezero crater show a distinct crystalline structure. But the landscape immediately looked different than expected, says planetary geologist Kathryn Stack Morgan of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Scientists thought they’d find compacted layers of soil and sand there, at the base of what they dubbed Lake Jezero. Perseverance landed on the crater floor about two kilometers from the front of the delta. ![]() That delta “is like this flashing signpost beautifully visible from orbit that tells us there was a standing body of water here,” says astrobiologist Ken Williford of Blue Marble Space Institute of Science in Seattle. At Jezero’s western curve, an etched ancient riverbed gives way to a dried-out, fan-shaped delta on the crater floor. It sits in an older and much larger impact basin known as Isidis. The crater formed sometime between 3.7 billion and 4.1 billion years ago, in the solar system’s first billion years. Jezero is a shallow impact crater about 45 kilometers in diameter just north of the planet’s equator. JPL-CALTECH/NASA, ASU, MSSS Perseverance finds unexpected rocks On the floor of the Jezero crater (shown on July 28, 2021), Perseverance found rocks that were volcanic in nature, not the sedimentary rocks that scientists expected from a dry lake bed. “We’re seeing that everywhere.” And the rover still has much more to explore. Perseverance has turned up carbon-bearing materials - the basis of life on Earth - in every sample it has abraded, Horgan says. That volatility has slowed the search for sedimentary rocks, but it has also pointed to new alcoves where ancient life could have taken hold. Jezero has a more dynamic past than scientists had anticipated. ![]() This basin has witnessed flowing lava, at least one lake that lasted perhaps tens of thousands of years, running rivers that created a mud-and-sand delta and heavy flooding that brought rocks from faraway locales. Hundreds of researchers scouring the data Perseverance has sent back so far now have some clues to how the crater has evolved over time. Volcanic rock is just one of the surprises the rover has uncovered. Since landing, “we’ve been able to start putting together the story of what has happened in Jezero, and it’s pretty complex,” says Briony Horgan, a planetary scientist at Purdue University in West Lafayette, Ind., who helps plan Percy’s day-to-day and long-term operations. It’s also collecting samples to return to Earth. Drilling, scraping and collecting pieces of the Red Planet, the rover is using its seven science instruments to analyze the bits for any hint of ancient life. Jezero was picked for the Mars 2020 mission because it appears from orbit to be a former lake environment where microbes could have thrived, and its large delta would likely preserve any signs of them. While the earlier rovers focused on Martian geology and understanding the planet’s environment, Percy is looking for signs of past life. The most complex spacecraft to explore the Martian surface, Percy builds on the work of the Curiosity rover, which has been on Mars since 2012, the twin Spirit and Opportunity rovers, the Sojourner rover and other landers.īut Perseverance’s main purpose is different. Nicknamed Percy, the rover arrived at the Jezero crater two years ago, on February 18, 2021, with its sidekick helicopter, Ingenuity. It was not made up of the layers of clay and silt that would be found at a former lake bed. The visible shapes along with the chemical compositions showed that this rock, dubbed Rochette, was volcanic in origin. Then the scientists watched on a video conference as the rover’s two spectrometers revealed the chemistry of those meshed textures. ![]()
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