A newly identified planet candidate, HD 137010 b, looks strikingly Earth-like in size and orbit — but it may be colder than Mars due to its dimmer star. If it has a thick enough atmosphere, though, ...

Mars, once a much wetter and more dynamic planet, is now a dry and inhospitable desert. The mystery of how the red planet ...

NASA's Perseverance rover discovered rocks on Mars, providing new evidence the red planet was once a wet, habitable world that could support life.

Since humans first started observing Mars, the existence of nocturnal ice clouds on the Red Planet has been known, primarily through daytime observations and sophisticated climate models. Twilight ...