Perseverance: why scientists already know where to look for life on Mars

“We are definitely in the right place.”

A sense of relief reigns in the science team responsible for the Persevere (Persevere, in Spanish) rover that the US space agency, NASA, has on Mars.

Investigators are now confident that they have sent the car to the place that offers the best possible chance of finding traces of life. on the red planet.

“Percy,” as the robot is affectionately called, landed at Jezero Crater in February and has since taken thousands of photos of the surrounding area.

The interpretation of those images is the basis of the first scientific article based on these discoveries, published this week in the journal Science.

Analysis confirmed that perseverance is now stabilizing At the bottom of what was once a great lake On Mars, which was fed by a meandering river that reached the western depression. We talked about something that happened More than 3.5 billion years ago, when the climate of Mars was more temperate.

From the perseverance observations, it was possible to deduce that the river was connected to the lake, the flow suddenly slowed down and the sediments suspended to form a delta, that wedge formation one can see in many places. Earth.

It was in that environment where Some microorganisms may multiply Remains may have survived to this day.

Professor Sanjeev Gupta of Imperial College London, co-author of the science paper, comments: “Some people have said to me: ‘What’s new in this? Didn’t we already know there was a delta in Jezero crater? “Well, actually, we didn’t know. We’ve inferred from the orbital images that Jezero has a delta but until you’re on Earth you can’t be completely sure. It could be that we were looking at a placer fan.”

An alluvial fan or gloom cone is a geological formation in which, in general, a fan deposits material in an energy-packed environment, such as a tidal.

If Mars’ microbes were present, they would have preferred the calmer, more durable waters of the delta.

Perseverance landed about two kilometers from the main delta, but the images taken with its telescope are the most attractive, especially when it lies on an isolated hill that scientists named Kodiak.

“It is possible to see in these remnants some of the stratification that normally produces developing deltas.”

There are horizontal bottoms consisting of fine granular sediments thrown out by the river from its entrance to the lake to the crater. Above these, sediments that have slid down the slope through more advanced deltaic lobes are visible. And higher still are the sediments deposited by the river after the edges of the delta have expanded beyond.

In addition to the Kodiak and the main delta formation, it is found in Jezero Lots of big rocks. This indicates that there were floods at later times in the crater’s history.

“Something has changed in the hydrology. We don’t know if it was a climate-related event, we don’t know,” says Professor Gupta. “To move such a large boulder, you need something like a flood. There were probably glacial lakes in the local basin that sent these water currents towards Jezero.”

“We see lake flooding on Earth, in places like the Himalayas. In the Ganges basin, there are these big rocks mixed in with normal river sand, and this is where a sudden flood of a glacial lake happened,” Gupta told BBC News.

The perseverance team will send you to the base of the main delta formation to dig into the terrain for small mudstones that are expected to be found. They will also focus on a ring of limestone around the edge of Jezero Perhaps represents the shores of the crater lake In its deepest era.

The robot is tasked with collecting and storing more than twenty rock samples from different locations. These samples will be brought from He returned to Earth in the early thirties To be tested in laboratories able to determine whether there are microscopic life forms on the face of Mars.

Plans for this are well developed and will include sending another robot from NASA and its European Space Agency partners to retrieve samples from the crater point where Perseverance stores them.

It will be a British-made vehicle. You’ll collect rocks and transfer them to a rocket that launches them toward a point in Mars’ orbit where it will wait for a satellite that will finally carry it back to Earth.

“We are about to enter the most exciting time for Mars exploration.”says Sue Horn, head of space exploration at the British Space Agency.

“With testing of the sampling vehicle’s propulsion system next month, the dream of examining samples from the Red Planet will soon become a reality.”

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