The engineering lesson is simple: Sometimes the best observatory is the one already parked at another planet. When an interstellar comet was in a viewing geometry that kept Earth-based telescopes too ...

A few months from now, a NASA spacecraft called the Mars Reconnaissance Orbiter (MRO) will begin its 20th year of observing the Red Planet from above. And, like most 20-year-olds on Earth, MRO's ...

New evidence of ancient rivers suggests Mars may have been a "blue planet," thanks to an ocean spanning its entire northern ...

The spacecraft that has quietly rewritten our understanding of Mars just crossed a very visible milestone: the Mars Reconnaissance Orbiter has captured its 100,000th close-up view of the Red Planet.

The 100,000th image captured by NASA's Mars Reconnaissance Orbiter. NASA/JPL-Caltech/University of Arizona NASA’s Mars Reconnaissance Orbiter (MRO) has been flying ...

First results from NASA's Mars Reconnaissance Orbiter provide provocative new evidence that there were diverse watery habitats capable of supporting life on Mars eons ago. MRO is also finding evidence ...

MAVEN was built to last in orbit until 2030 — that's not looking likely anymore.