Origins of Life : Mars

"We have one data point for life on a planet. Mars is the second data point."

"We know from the investments that we've made from exploration that there was this habitable world right next door. Right about the time that Earth was developing its life, Mars was also habitable, with lakes and rivers."

Bethany Ehlmann, California Institute of Technology

"Is it a foregone conclusion that as long as you have the right mix, things are going to happen and you're going to end up with life?"

"We don't really have the answer to that."

Mary Voytek, head, astrobiology program, NASA

"[Even if the mission fails to discover signs of life, it may detect] some kind of prebiotic phase of life."

"If we could bring back a fossil record, a rock record, some kind of geological samples, that have some record of that prebiotic phase of the evolution of life, that would arguably be as exciting, or arguably more exciting, than finding life."

Benjamin Weiss, Perseverance science team, professor, Massachusetts Institute of Technology

A false color image of Jezero Crater, as seen from above from NASA’s Mars Reconnaissance Orbiter

Image: NASA

Perseverance,  the NASA rover, is scheduled to blast off for Mars tomorrow, Thursday 29 July, to collect rock and soil samples for close scrutiny once they eventually are brought back to Earth. The hopeful expectation is that scientist looking for fossils or "biosignatures" of organisms that may once have thrived some 3 billion years ago at a time when Mars was much warmer and wetter, will discover on close scrutiny, the beginnings of life that might give clues to our own.

Ancient Martian life and life on Earth could suggest a common origin, conceivably one planet

'seeding' the other through meteorite-transmission. Another hypothesis is that Mars possessed life forms of a nature alien to our own; alternatively, possibly life forms of any description never emerged on Mars which may then have always been a sterile world, absent life forms. Any way the evidence unfolds, it will still represents knowledge about the universe and our place within.

Known as Mars 2020, the new rover mission is the first installment of a multiphase project named the Mars Sample Return campaign. The intention is for Perseverance to launch from Florida's Cape Canaveral via an Atlas V rocket. China on Thursday last launched its own probe, named Tianwen-1, the country's first effort to land a spacecraft on Mars. NASA, for its part, has been racing against a natural deadline.

A narrow window when Earth and Mars become positioned most favourably for a launch which must take place by August 15, for following that date the effort would have to wait a few years on. Tomorrow's mission is scheduled to land on Mars February 18. To do so, Perseverance must descend to Mars' surface in the Martian atmosphere; too thin to assist in braking, but insufficiently thick to cause aerodynamic problems. It must land intact, upright and functional.

Autonomous navigation sensors should permit a pinpoint landing in Jezero Crater, a site painstakingly selected by scientists, where a river delta once flowed into a deep lake. The selection suited the goal, to discover a site promising the potential of remnants of ancient organisms to be found there. For collection purposes of critical samples the rover carries an instrument able to manufacture oxygen from Mars' carbon dioxide rich atmosphere, critical to future human-accompanied missions.

A small helicopter named Ingenuity, slated to perform the first rotorcraft flight on another planet, is carried by the rover. Equipped with a drill and 31 canisters, the rover is meant to scout out the most promising sites with the aid of the helicopter providing aerial surveillance, after which the rover will drill into the Mars surface and place Martian soil and rock cores into the canisters. They will be left scattered on the surface.

In 2026, a subsequent rover will collect the canisters, placing them into a launch vehicle, scheduled to be blasted into orbit around Mars from where it will be transferred to an orbiting spacecraft scheduled to carry the samples back to Earth in 2031, according to current NASA plans. Complex and ambitious.

An artistic rendering of Perseverance with its primary robotic arm extended, drilling into the surface of Mars. 

Image: NASA 

"Rovers are the closest we can get to having a geologist on Mars at the moment, so any new rover data is really valuable."

"Every time we have a rover like this, a wave of discoveries follows. It’s a very exciting time."

Mathieu Lapôtre, assistant professor, geological science, Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth)

"As a geologist, I know the importance of time in the field, looking at the rocks.The more time  you spend looking at the rocks, the better you're going to understand any potential biosignatures."

"If it's life, it would not be just one. It will be multiple examples of whatever you are looking at."

Abigail Allwood, geologist,  Jet Propulsion Laboratory, NASA

Engineers load the titanium sample tubes into Perseverance ahead of launch.

Image: NASA