Space – Alone in the universe? NASA back to Mars to find out

Seven months of space travel, decades of work and billions of dollars to answer a single question: Did life ever exist anywhere other than Earth? NASA’s quest culminates Thursday with the landing on Mars of its latest rover, Perseverance.

Image d’illustration.

AFP

For the first time, the mission of the American space agency has the explicit goal of finding traces of ancient life on the red planet, by collecting over several years up to thirty rock samples.

The sealed tubes will then have to be brought back to Earth by a future mission, in the 2030s, in order to be analyzed, and perhaps finally be able to answer “one of the questions that have inhabited us for centuries, namely, are we alone in the universe? ”said Thomas Zurbuchen, associate administrator for science at NASA on Wednesday.

Perseverance is the largest and most complex vehicle ever to be sent to Mars. Built at the legendary Jet Propulsion Laboratory in California, it weighs a ton, is equipped with a robotic arm of more than two meters and 19 cameras. He attempted a very perilous maneuver on Thursday, on the most risky landing site ever attempted, because of its relief: the Jezero crater.

Shortly after 8:30 p.m. GMT (9:30 p.m. in Switzerland), it will enter the Martian atmosphere at a speed of 20,000 km / h, protected by its heat shield which will not be released until after the opening of a huge supersonic parachute. Eight motors pointed at the ground will eventually slow him down before he deploys his six wheels, suspended along cables until contact with the ground.

“The sky looks clear for landing tomorrow. But even with a clear sky, the landing is the most dangerous part of the mission, and we cannot guarantee its success, ”recalled at a press conference Allen Chen, responsible for the vertiginous descent.

If Perseverance arrives intact, the first images could be transmitted soon after. Proof that the mission is also the result of international cooperation: French President Emmanuel Macron, whose country designed one of the rover’s many scientific instruments, will attend the landing at the Paris headquarters of the National Center for Space Studies (Cnes).

Good luck?

Researchers believe that the Jezero crater, more than three and a half billion years ago, housed a deep lake about 50 km wide. “We have very strong evidence that Mars could have harbored life in the distant past,” said Ken Williford, deputy head of the mission, on Wednesday. “The question is: is (life on) Earth an anomaly, a stroke of luck?”

The first samples should start this summer. Several routes are possible in order to dig in different environments, including the shore of the old lake, and the delta formed by a river flowing into it.

Scientists are looking for what they call biosignatures: traces of microbial life that “can take all kinds of forms,” ​​for example “chemicals” or “environmental changes,” said Mary Voytek, program director. astrobiology for NASA. “We astrobiologists have dreamed of this mission for decades,” she said enthusiastically.

“Either we find life, and it would be an exceptional find, or it isn’t, (..) and it will suggest that not all habitable environments are inhabited,” warned Ken Farley, scientist. of the project. And that we will have to look elsewhere.

The 450 or so team members who will pilot this phase will also work in exceptional conditions because of the Covid-19 pandemic, he stressed: “the mission will be carried out from the people’s lounge, all over the place. of the globe ”.

Helicopter and oxygen machine

The first months of the mission will not however be devoted to this first objective. Parallel experiments are planned. NASA wants in particular to prove that it is possible to fly a motorized vehicle on another planet. The helicopter, baptized Ingenuity, will have to be able to rise in air with a density equivalent to 1% of that of the Earth’s atmosphere. Two microphones could also, for the first time, record Martian sound.

NASA will also experience the production of oxygen directly on site. An instrument called MOXIE, the size of a car battery, should be able to produce up to 10g of oxygen in an hour, by sucking carbon dioxide from the Martian atmosphere – much like a plant. This oxygen could be used by future human settlers to breathe, but also as fuel.

Perseverance will only be the fifth rover to set foot on Martian soil. Since the first, in 1997, they have all been Americans, and one of them, Curiosity, is still in business. But China recently placed its “Tianwen-1” probe into orbit around Mars, containing an unmanned robot that is expected to attempt to land around May.

AFP

Posted today at 5:11 am

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