The number of successful missions to Mars has exploded since the start of the 21st century. As has the number of countries sending them.
Discoveries include more signs that water once flowed on Mars. They also show evidence of thousands of massive ancient volcanic eruptions. Plus, the remains of ancient hot springs. These suggest that at one time, Mars was a planet with a hot center. In this way, it was much like Earth. Did life as we know it ever exist on Mars? Even tiny microbes? The findings were uncovered by spacecraft of the 21st century. These include orbiters, landers, and rovers. The findings suggest that life was possible.