You’ve probably heard NASA’s announcement: Mars has seasonal water flows.
However, not a lot of people understand the implications. On Earth, we find life wherever water flows. On Mars, we might just find the same thing. Unfortunately, the Outer Space Treaty of 1967 prohibits “anyone from sending a mission, robot or human, close to a water source in the fear of contaminating it with life from Earth.” Curiosity and Opportunity, the two functional Mars rovers, are banned by this treaty from investigating, so NASA can’t look for actual life there yet.
If life exists on Mars, even in the basest single-celled organisms, everything on Earth might be descended from it. The Smithsonian‘s website says that Earth started to have life somewhere between 2.7 and 3.5 billion years ago. While it is still likely for life on Earth to have started here, it’s possible it could have been otherwise. First, three billion years ago, Mars had a much thicker atmosphere, and a lot more liquid water. Life could have formed there, and that life might have been able to survive on Earth. Second, there is an elliptical depression called the Borealis Basin that encircles mars. One possible explanation for this crater is that a massive chunk of rock half the size of Mars collided with what used to be Mars. This rock, of course, would send a lot of debris flying. While not likely, it’s not impossible that a larger chunk could have brought life to Earth, and that this life could have flourished and been the origin of all life on Earth. The discovery of water on mars is like the transition from a geocentric to a heliocentric theory in importance. Everyone knew Earth might not be the first planet in the universe to have life, but now Earth might not even be the first planet in our solar system to have life.