NASA’s Mars 2020 rover is designed to be able to identify possible traces of ancient life on Mars. (Credit: NASA)
A Senate subcommittee asked about the reasons for sending humans to Mars, and, boy, they get one of Ellen Stofan, NASA’s former chief scientist.
Stofan, who now leads the Smithsonian’s National Air and Space Museum, suggested that if we really want to find and to understand the possible traces of ancient life on the Red Planet, robots can’t do it alone: we need the people on the ground.
“I am optimistic that life did evolve on Mars, I’m not optimistic that it will be very complex, so we are talking about finding fossil microbes,” Stofan told a Senate subcommittee dedicated to the science of problems on Aug. 1, adding that those fossils would be incredibly hard to find. [The Search for Life on Mars (A Photo Timeline)]
“That is why I think that the will of the people on the planet, the break-up of a piece of the rocks to try to actually find this evidence of past life,” Stofan said. “And finding a sample is not good enough; you must have multiple samples to understand the diversity.”
NASA has not yet sent a robot is designed to identify traces of life on Mars since the Viking missions in the 1970s. But with the soonest possible human Mars mission is still a decade and a half away, there is some hope that robots can locate ancient Mars life for the people there?
Or our lives, hunting the emissaries are mechanical or human, they will be guided by what we have learned on the Earth — and the discovery of ancient microbial life is already difficult here, Frances Westall, an astrobiologist at the National Centre for Scientific Research in France, told Space.com. Westall, looking for traces of ancient microbial life on Earth, said: “That is still very controversial, and that is who will have access to the most advanced laboratories on Earth.” Now, she said, that the work always depends on a combination of on-site man-and in the distance the labs — no robots involved.
Just like here on Earth, and scientists are fighting some grim odds if it comes to the hunting traces of martian organisms that may have lived billions of years ago. “Of course, most things never fossilize; a few things do get stored, usually those things that are hard to share,” Sean McMahon, an astrobiologist at the University of Edinburgh in the united kingdom, told Space.com.
But on one front, the search for ancient life on Mars has a leg up above the earthly equivalent, because Mars is no phenomena such as plate tectonics and volcanism continually destroying the geological record, Tanja Bosak, a geobiologist at the Massachusetts Institute of Technology, told Space.com. So if there was life on the Red Planet billions of years ago, traces might remain.
Robots against humans
Mars has attracted eight successful landers and rovers over the years, with the highest-profile of the current occupant is NASA’s Curiosity rover. The mission was carefully designed to search for places where life once flourished, but not to search for traces of life.
And it has done just that, the identify of mudstones in Gale Crater, in particular, is promising, and the spot of the old organic molecules are not necessarily created by life. But robots are not perfect, and there are still lots of lingering questions about Mars geology, he added. “There are rocks that rovers have visited and made visible and analysed, and we are still arguing about what they are,” McMahon said. [Ancient Mars Lakes & Laser Explosion: Curiosity’s 10 Biggest Moments in the 1st 5 Years]
But robots are much stronger than the man. “The place where I would start the conversation where it was safe to land, and the robot program has shown the possibility for landing in difficult terrain,” Ken Farley, an astrobiologist at the California Institute of Technology and the principal investigator for NASA’s next Mars rover, told Space.com, adding that robots can the country closer to the rocks, scientists want to look at. While the people are more mobile than robots, Neil Armstrong and Buzz Aldrin that only about 90 yards (82 metres) during the moon landing.
Because Mars life is probably never larger than microbial, functions scientists are looking for are going to fit within a robot. But there are a number of ways people still higher than the robots, in particular when it comes to look at the bigger picture of life on Mars. “Biologists, geologists and chemists on the ground could do more than identify evidence of past life on Mars,” Stofan told the senators. “They could study the variation, complexity, and the relationship to life on Earth much better than our robot emissaries.”
And Westall said that they don’t think that robots will ever match the human geologists for their knowledge and instincts in the field, or their productivity. “I’m a geologist and I go in the field and I need to see things with my eyes, and if I had the chance I would go to Mars,” she said. “A man is a geologist can do in a week what the Mars rovers can do in a year.”
The best of both worlds?
But there is a kind of compromise, that can be even more productive than the landing of man on Mars. The secret is in the steel-back missions, in which robots collect rocks for scientists to study in terrestrial laboratories. NASA and its Japanese counterpart each currently have missions on asteroids.
The sample-return format scientists have a lot more freedom to their curiosity, gives them the strength to do a day to answer questions, they do not yet know to ask, said Farley. He pointed to the research of the infamous Allan Hills 84001 Mars meteorite, which is an argument for the evidence of fossilized life, because disempowered, he rested on the presence of small magnetic minerals. “You would never be able to do the measurements [Mars] because you never would have dreamed of sending an instrument that would be able to do.” [Top 10 Discoveries by Mars Rovers Spirit & Opportunity: A Scientist’s View]
And of course, there are the limitations that are inherent in the purchase of an instrument to Mars, said Farley — it has consequences for an instrument in size, weight, power, sensitivity to radiation, and much more. Unless we build a stunningly advanced laboratory on Mars, we will always need to have to take samples home to study in earnest, Bosak said. “It comes down to the lab, not a lab, multiple labs, really, a whole program that is dedicated to analyzing the samples in a clean way,” she said.
That is much more obvious here on Earth, that is where NASA’s next Mars mission, called the Mars 2020 rover and the launch of that year, comes in the picture. It will mimic Curiosity skeleton, but is tailored to search for traces of life, instead of only environments that may once have been suitable for it. And it will select and stashing pieces of intriguing Martian rocks in the hope that a future mission will come and pick it up, return it of about a pound (0.5 kilograms) of Mars rocks to earth laboratories.
But now, NASA is not working on that future mission: Mars 2020 is the latest Red Planet scheme, which the National Academies of Sciences declared in a report published Aug. 7. The Mars 2020 team is just to contribute with their own work, in the hope that eventually someone will pick up their souvenirs.
Sure, people are good at picking up objects during their travels, and as engineers have developed the capacity to bring people back from Mars, they certainly can manage a few pounds of rock. So a manned mission would probably have the same advantages as a robotic sample return mission.
But maybe the robots have earned this. Every clue we have that Mars was once habitable and still hide the traces of that life comes from robots, not people on the ground, and finding life is perhaps not the best way to advocate for a manned mission.
“The value of human exploration and reconnaissance,” Bosak said. “You can’t deny the appeal, but that is a separate matter from being able to find life on Mars.”
Original article on Space.com.