Water is likely to have arrived in a cold climate, according to
the data. When it warmed up, however, the lake split into
layers with a warm, oxygen-rich mix near the top. Not
surprisingly, life stood the best chance there. After that, you
may know the rest — Mars
lost most of its atmosphere and the water to match.
The findings suggest that the timeframe for potential life on
Mars, at least in Gale Crater, is much longer than previously
thought. This doesn’t guarantee that humanity will find
fossilized microbes, but the odds are better than before. As
observes, life on Earth took “just” a few hundred million
years to form after the planet itself was born; 700 million
years is a huge window by comparison.