In the search for evidence of water and life on Mars, scientists have discovered the red planet once had rivers larger than our own.
As humankind continues to search beyond Earth's atmosphere for signs of life, other than finding a living thing, we are looking for water. As far as we know, based on what we have here on our own planet, all living things need water to survive. Ergo if we discover water on a planet, or evidence that there ever was water on a planet, then we know there is or could have been life there.
Since Mars is the closest planet to our own, that is the one we have learned the most about so far. NASA continues to send probes and Mars Rovers to the red planet to try and figure out what exactly happened on its surface throughout its history. There has even been talk recently that one of those rovers has discovered life, in the form of algae and fungi as opposed to intelligent life.
While that is yet to be confirmed, what scientists are now sure of is that huge rivers once flowed over the surface of Mars. Rivers twice as wide as your average Earth river, reports Space.com. What is most surprising about that is how long those rivers flowed. It's believed that Mars's atmosphere was almost entirely stripped away 3.7 billion years ago. However, this new evidence shows that rivers continued to flow up until around 1 billion years ago.
Age estimates of the more than 200 ancient waterways on Mars show that the planet actually had precipitation-fed flowing water for most of its 4.5 billion year history. It also wouldn't have been a case of them gradually fading away until they disappeared entirely either. The study also shows that those rivers would have remained as big and strong as ever right up until they disappeared completely.
As fascinating as this discovery is, it raises as many questions as it answers. What scientists don't yet understand is how these Martian rivers continued to flow without the support of a proper atmosphere. The hope is that the newest Mars Rover will help with that. It is due to launch in July 2020 and will study an ancient river delta in the river's Jezero Crater.