One question has fascinated humans since, well, the beginning of time: Are we alone in the universe? So far, despite our constant scanning of the heavens for proof, the answer seems to be a resounding yes. But that hasn't stopped us from pouring billions into an upcoming mission to Mars to see if it does, or could have sustained life.
Now that we know there's flowing water on Mars and that it once had an Earth-y atmosphere that might've allowed humans to crash there, NASA astrobiologist David Des Marais told Quartz there's actually a really important reason we need to visit the red planet.
Not only could what we find there help explain how life started on Earth, or how we might be able to bioengineer life on our own, but it might help decode why despite their similarities during formation 4 billion years ago, life was able to take hold on Earth while Mars became a dry, inhospitable rock floating in space.
"Mars, with maybe an arrested stage of development because of the change in the environment could be the only place anywhere we could get an insight of how life could begin in an Earth-life environment," Des Marais said.
Since there is no life on Mars, the best place to find that record would be in fossils or other places where biological records could be trapped, like hot springs and shallow springs: "If they're on the surface and they're sort of in a suspended animation, sort of a hibernation or something, if it's two miles down you can't get at it," he said of signs of life. "But if there was a discovery of a fossil you could start this path of figuring out where it came from then I think the public and funding sources would be much more amenable to doing what it takes to really trying to find life itself... alive."
If we could find any traces of chemical evolution, Des Marais said that would be "profoundly important" to scientists, helping them go from doing lifelike experiments in the lab to really finding out about the origins of life itself. Before we send humans up, though, the Airbus Group has plans to send the ExoMars ESA rover to the planet in 2019 to scour the surface for signs of "microbial life, past or present."
"The biggest thing about going to Mars is the adventure," Dean Regas, astronomer at the Cincinnati Observatory -- home to the oldest telescope in the nation open to the public -- told MTV News. "I think finding life outside of the Earth will be the story of the 21st century and I really think we will find it. Mars had standing water in great quantities on its surface at some point and the atmosphere was much different, but now you can't breathe there and it looks as dry as the Arizona desert."
Regas said the big question is what happened on Mars, what ramifications it might have for us and how we can make sure we don't have the same thing happen on our planet?
A New Way To Measure Gravity Could Also Help
Meanwhile, an international group of astrophysicists has developed a new way to measure surface gravity on far-away stars that might help tell us if some planets in other solar systems could sustain life.
In an article published in the journal Science, the group described how they studied slight variations in the brightness of the stars -- caused by surface turbulence and convection -- focusing on so-called "Goldilocks" planets that are either are not too hot or too cold, but could be "just right for liquid oceans and to support life as we understand it," according to the Vancouver Sun.
Figuring out if the planets could support life depends in part on the properties of the stars that orbit them, with the new methods allowing scientists to measure how big and bright the stars are and if their pair planets are the right size and temperature to have liquid oceans and maybe sustain life. "Whether we first find life on a planet 50 light years away or 5,000 light years away, the distance of the planet will be a footnote in the history books," said Jaymie Matthews of the University of British Columbia. "The headline will be 'We found life!'"
Just finding that there are other planets out there that orbit other stars is one of the biggest discoveries we've made in recent years according to Regas.
"It's not a surprise that they're out there, but it's a surprise that there's so many of them," he said, noting that it's not one-tenth of one percent, but possibly 20 percent or more. "It boggles my mind to think we have the technology to see small planet trillions of miles away circling a star."