The fact that the cold, dry Mars of today had flowing rivers and lakes several billion years ago has puzzled scientists for ...

The fact that the cold, dry Mars of today had flowing rivers and lakes several billion years ago has puzzled scientists for decades. Now, researchers think they have a good explanation for a warmer, ...

"It's been such a puzzle that there was liquid water on Mars, because Mars is further from the sun, and also, the sun was ...

Harvard scientists explain how Mars had warm spells billions of years ago, allowing rivers and lakes to exist.

The redox states of the atmosphere ... they plan to compare those results to rocks from the upcoming Mars Sample Return mission. Because Mars lacks plate tectonics, unlike Earth, the surface ...

This prompted the team to apply a similar process to Mars as is used on Earth to track pollutants, allowing them to model how the hydrogen content of the Martian atmosphere changed over time.

The image below, taken by the European Space Agency's Trace Gas Orbiter (which arrived at Mars in 2016), shows one of the ...