The data provided by Curiosity, the rover sent to the Red Planet, tells us some interesting things after the 3.5 years of mission.
The discovery refers to the fact that in one of the former lakes on Mars there were conditions to sustain life. The oxygen level in the water was higher on the surface and lower in depth, just as lakes of Earth.
We can understand that the Martian environment could have provided many opportunities for the survival of some microbial species.
Analyzing several layers of rock on the bottom of Gale Lake, which is now completely dry, the rover discovered that the water was richer in surface oxidants than in the deep, so there could have been many life forms.
We do not have any clear proof that Mars was once alive, but this is becoming more and more a reality. We know that oxygen is essential to life, and due to the fact that Lake Gale had oxygen, the researchers are sure there were forms of life.
After many analysis, it was concluded that in the very distant past of Mars, it was more similar to Terra. The sediment types found on the bottom of the lake on the neighboring planet are normal on ours.
The fact that there was liquid water now on Mars for a long time, life forms had a good opportunity to grow and develop.