Tonight (Jan. 13), bright Mars will disappear behind the full Wolf Moon for several hours before reappearing on the other side. It's the only lunar occultation of Mars visible from the U.S. this year.

Mars has a thin atmosphere of carbon dioxide, endless expanses of dusty landscape, and about one-third of Earth's gravity. Can humans even live on Mars? In a perfect universe, we would change Mars ...

The HI-SEAS mission, or Hawaii Space Exploration Analog and Simulation, takes place near the Mauna Loa volcano in Hawaii and is designed to simulate living on Mars. Crew members live in isolation ...