Is there life on Mars? NASA scientists to hunt for Martian life in Jezero Crater, once home to a river delta
The 36-million-year-old crater could hold clues to whether Mars is capable of supporting life; the mission will also look at how Mars dried out.
Come 2021, NASA’s robot will hunt for signs of ancient life on Mars. This comes after scientists zeroed in on Jezero Crater on Mars - once home to an ancient river delta - which could be the perfect site to look for fossil records of microbes. The ancient river basin is about 36 million years old.
The 28-mile-wide Jezero crater (image NASA/JPL-Caltech/ASU) will be the landing site for NASA's Mars 2020 rover. The Mars 2020 mission is set to find out whether Mars is capable of supporting life. So the team will study both the crater floor and delta during the rover's two-year prime mission, according to NASA.
"The rover mission is scheduled to launch in July 2020 as NASA’s next step in exploration of the Red Planet. It will not only seek signs of ancient habitable conditions – and past microbial life - but the rover also will collect rock and soil samples and store them in a cache on the planet's surface. NASA and ESA (European Space Agency) are studying future mission concepts to retrieve the samples and return them to Earth, so this landing site sets the stage for the next decade of Mars exploration", says NASA.
According to Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, the landing site in Jezero Crater offers "geologically rich terrain, with landforms reaching as far back as 3.6 billion years old, that could potentially answer important questions in planetary evolution and astrobiology. Getting samples from this unique area will revolutionize how we think about Mars and its ability to harbor life”, adds Zurbuchen.
NASA chose the site after an instrument named Compact Reconnaissance Imaging Spectrometer for Mars instrument, or CRISM, aboard the Mars Reconnaissance Orbiter showed that the crater hosted minerals called carbonates. On Earth, these minerals have been shown to be ideal for preserving ancient life.
"CRISM spotted carbonates here years ago, but we only recently noticed how concentrated they are right where a lakeshore would be," says the paper's lead author, Briony Horgan of Purdue University in West Lafayette, Indiana. "We're going to encounter carbonate deposits in many locations throughout the mission, but the bathtub ring will be one of the most exciting places to visit", says Horgan.
The mineral was specifically identified on the site's western rim, called 'the marginal carbonate-bearing region'. With this information provided from the orbiter, the lander-rover will probe the surface of Mars and return rock core samples to Earth, where it will be analyzed.
"The possibility that the 'marginal carbonates' formed in the lake environment was one of the most exciting features that led us to our Jezero landing site. Carbonate chemistry on an ancient lakeshore is a fantastic recipe for preserving records of ancient life and climate. We're eager to get to the surface and discover how these carbonates [are] formed", says Mars 2020 Deputy Project Scientist Ken Williford of NASA's Jet Propulsion Laboratory in Pasadena, California. JPL leads the 2020 mission.
Besides carbonates, the team will also investigate another mineral called hydrated silica which is as capable as carbonates in conserving records of the past. Thanks to a new study, the team knows where to look for the mineral: the study finds that it is present on the edge of the ancient river delta. The team believes that the Mission will be a hit if the rover specifically detects hydrated silica in the bottom layer of the delta - an ideal site for buried microbial fossils.
The carbonate can also serve another role: they can explain how Mars dried out. The Red planet turned into the freezing desert that it is today, shedding its former state, filled with liquid water and a thicker atmosphere - that was more conducive to life.
The study has been published in ICARUS.