NASA's Mars rover Curiosity has begun the steep ascent of an iron-oxide-bearing ridge that's grabbed scientists' attention since before the car-sized rover's 2012 landing.

The sharp eye of NASA's Hubble Space Telescope has captured the tiny moon Phobos during its orbital trek around Mars. Because the moon is so small, it appears star-like in the Hubble pictures.

NASA has found diverse minerals in rocks examined by the Curiosity rover on lower Mount Sharp, Mars. These suggest that wet environmental conditions there changed over time.

A long-lasting lake on ancient Mars provided stable environmental conditions that differed significantly from one part of the lake to another, according to a comprehensive look at findings from the first three-and-a-half years of NASA's Curiosity rover mission.

Pale "halos" around fractures in bedrock analyzed by NASA's Curiosity Mars rover contain copious silica, indicating that ancient Mars had liquid water for a long time.

A new observation from NASA's Mars Reconnaissance Orbiter (MRO) captures the landing platform that the rover Opportunity left behind in Eagle Crater more than 13 years and 27 miles (or 44 kilometers) ago.