Last time we learned about Mars' great Valles Marineris, the largest canyon in the solar system. But what about here on Earth, is the Grand Canyon really the biggest? What I thought to be a simple ...

Valles Marineris West of Hydraotes, we find one Mars's greatest attractions, Valles Marineris. It's the largest canyon in the solar system, running the length of New York to Los Angeles ...

From arachnid-like formations and mysterious blobs to an underground ocean and a giant volcano, here are our 10 favorite things scientists discovered on Mars this year.

Ancient rainstorms may have sculpted the red planet, similar to the monsoon rains that helped shape the Southwest’s landscape ...

Key features to observe on the rusty-red surface of Mars include the canyon systems of Valles Marineris; the largest volcano in the solar system, Olympus Mons; and the planet's southern polar ice cap.

A rare astronomical event will take place as Mars disappears behind the full moon in a lunar occultation. This event, visible from the United States on January 13, marks the only lunar occultation of ...