The first color photo of the Martian surface, taken in 1976 by the Viking 1 probe. To survive on Mars' surface, astronauts will need oxygen, which only exists in trace amounts in the Martian ...

Oxygen is everywhere on Earth today. But that hasn’t always been the case. Scientists think oxygen only became a lasting part ...

While the gradual consumption of oxygen on Earth presents a worrisome scenario, this process is going to take a few billions of years. In the course of this highly unlikely destiny, planetary ...