Madrid, 25 (European press)
Scientists believe that watery Mars could have supported life billions of years ago. “These types of environments on Earth are where life thrives. The goal of exploring the Jezero Delta and the crater is to search these once-inhabited environments for rocks that may contain evidence of ancient life,” explains an astrobiologist and University of Florida Associate Professor Geologist Amy Williams, one of the long-term planners of NASA’s Perseverance mission, determines where to send the rover and which tests and samples to prioritize.
The rover is exploring the river delta to collect more rock samples for the Mars sample return mission. Led by NASA’s Jet Propulsion Laboratory, Perseverance touched down at the bottom of the Jezero Crater in February 2021. Since then, scientists have explored the geological makeup of the crater’s floor using an array of instruments aboard the spacecraft. The chemical composition of the rocks, as well as seeing their underground structure.
The scientific team found that the floor of the crater had eroded more than expected. Erosion revealed a crater made of rocks formed from lava and magma, known as igneous rocks. Scientists originally expected that sedimentary rocks from lakes or deltas would lie on top of these igneous rocks. The softer sedimentary rocks have likely eroded over the centuries, leaving behind the stronger igneous rocks.
The rocks that scientists analyzed and stored have been altered to return to Earth by water, further evidence of a watery past on Mars. “We have organisms on Earth that live in very similar rock types,” Williams recalls. “A water change of minerals has the potential to record biosignatures.”
NASA and the European Space Agency plan to return rock samples to Earth around 2033. The ambitious plan calls for building the first rover that can be launched from the surface of Mars and rendezvous with an orbiter to transport the samples back to Earth.
The reward for this task will be very detailed studies of rock samples that cannot be performed on the rover. These studies include measuring the age of rocks and looking for signs of ancient life. Because rock samples from the bottom of the crater probably predate the river delta, dating these rocks will provide important information about the age of the lake. “I’m excited about what’s coming next,” Williams says.