today, Mars is a wasteland. It is a dusty, rugged desert full of potholes. There is no visible life on its surface. But over the past decades, scientists have found evidence of a Mars lostwhich looked more like Earth Who like hell.
“You can see evidence of what Mars was like 4 billion years ago,” says a NASA astrobiologist. Lindsey Hayes. Carved into its rocky surface, “you see things like the remains of a huge river delta,” she says. See clues to past lakes. This makes the imagination go. “There were probably clouds in the atmosphere,” Hayes says. “The surface would have been very beautiful.” Previous missions to Mars – including robotic vehicles, landers, and orbiters – You have He added evidence on Earth that this watery past is very likely.
And that’s the most exciting thing for an astrobiologist like Hayes: Wherever there was water, there could have been life. “One of the universal features we see in life is that it needs water,” she says. There is life that lives without light, there is life that lives without oxygen. Nothing we know survives without water. If there was water on ancient Mars, “well, there was probably life that lived in that water,” she says.
The last episode of unexplainable – The Vox podcast that explores the big puzzles, unanswered questions and all things we Learning by diving into the unknown is about searching for a key piece of evidence that would confirm whether there was life on the ancient planet Mars.
perseveranceNASA’s newest rover that landed on the red planet in 2021She is currently exploring an ancient, dry river delta. The hope is that some of the microbial life forms that lived – and died – billions of years ago are preserved in their sediments. (It is unlikely that anything is currently alive on Mars.) The rover is now looking for rock samples that may eventually be returned to Earth for careful study; They will become the first Martian rocks returned to Earth by a science mission (we have some Martian rock samples that He reached Earth through a meteorite).
But… what if we find it? What if the evidence for past life on Mars is confirmed?
Finding life on Mars could help us understand how widespread life is in the universe
“The reason I’m interested in the search for life has to do with the concept of how interconnected life is on Earth,” Hayes explains.
Any two people have a common ancestor if you look far enough in family trees. But the same is true for all forms of life. A common evolutionary ancestor associates human and chimpanzee, chimpanzee with frog, frog with insect, and insect with fungal spores. All life on Earth is connected, via Last Universal Common Ancestor (or LUCA), a putative microbe that lived billions of years ago.
For Hayes, that relationship raises an epic question.
“So, given that all life on this planet seems to be related to each other, what would life be like on a different planet?” She asks.
It is possible, though not guaranteed, that if persistence finds evidence of past life on Mars, scientists can determine whether it likely shares a common ancestor with life on Earth. (“All life on Earth shares some similarities,” she says, “using DNA/RNA to store ‘information’ and most of the same amino acids in their proteins. If we find life on Mars that shares these similarities,” that might be related to life. on the earth.
If life on Earth and Mars had a common ancestor, this means that life likely began on one planet and then somehow passed on to the other (most likely by a meteorite). It is possible that life did not begin on Earth But instead on Marsor perhaps somewhere else in space.
But if life on Mars looks very different from life on Earth, it could mean that “life is a process so fundamental to the universe that you can have two different life-generating events in the same solar system,” Hayes says. This means that life may be more common in the universe than we currently think.
Hayes warns that answers to these epic questions may still be elusive, even with the best possible rock samples. Scientific evidence is often ambiguous, and any overarching conclusion is sure to be debated.
But the fact remains: Mars is a very important place in our solar system to investigate these questions.
And there could be, now, a simple rock lying on the surface of Mars, with epic evidence carved into it. Maybe, just maybe, our roving robot will find that rock, collect it, and show us how special life really is.