The engineering lesson is simple: Sometimes the best observatory is the one already parked at another planet. When an ...

When an interstellar comet goes behind the Sun from the Earth’s perspective, science does not hit pause it relocates. In the ...

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 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 ...

Using images from cameras on Mars orbiters, an international research team has discovered structures on Mars that are very similar to classic river deltas on Earth. These are traces of rivers that ...