Perseverance touched down on the Red Planet in early 2021 and has been active ever since. The rover was designed to explore the Jezero crater, a 28-mile-wide...
Mars had a wet past. If there had been life in that wet past it would have taken over the entire planet. A process we don’t see evidence for but should.
Which means that either life is rare or life on Mars was unlike life on earth. Of the two, the former requires less assumptions. The default is no life. The default is not life that is radically different than earth life.
Or, the window of habitability on Mars was much shorter than on Earth, and there just wasn’t time for complex, multicellular life to evolve. On Earth, life existed for billions of years before multicellular critters popped up. I think one day, a rover is going to turn over the right rock and we’ll see a little smudge of fossilized algal mat. But I am an optimist.
I am still betting we won’t find life there.
Mars had a wet past. If there had been life in that wet past it would have taken over the entire planet. A process we don’t see evidence for but should.
Which means that either life is rare or life on Mars was unlike life on earth. Of the two, the former requires less assumptions. The default is no life. The default is not life that is radically different than earth life.
Or, the window of habitability on Mars was much shorter than on Earth, and there just wasn’t time for complex, multicellular life to evolve. On Earth, life existed for billions of years before multicellular critters popped up. I think one day, a rover is going to turn over the right rock and we’ll see a little smudge of fossilized algal mat. But I am an optimist.
Maybe. Wouldn’t explain why the atmosphere wasn’t forever altered.