The Seven Wonders of the Solar System

People like to make lists of things, especially lists of superlatives: the best, fastest, oldest, largest, heaviest and so on. There are lists of the ten fastest animals and the ten longest rivers and even of the ten highest-paid rock stars. The Guinness company created a small industry from publishing lists exactly… » 9/14/14 3:30pm 9/14/14 3:30pm

Soar through the largest canyon in the solar system

At 10 km deep and over 4000 km long, Valles Marineris is not only the largest canyon on Mars, its the biggest in our entire solar neighborhood. Here, thanks to data collected by ESA's Mars Express, is your chance to get an up-close view of this craggy Martian scar. » 7/15/13 4:00pm 7/15/13 4:00pm

10 Unsolved Martian Mysteries

For decades, humanity has been launching missions to Mars, in hopes of making sense of the enigma that is our solar system's most Earth-like planet. And as with all good mysteries, many of our investigations have simply led to more questions. » 11/28/11 10:24am 11/28/11 10:24am

Mars's Grand Canyon is as long as the United States

This is the Valles Marineris, believed to be the biggest canyon in the entire solar system. At nearly 2,500 miles long, it would stretch clear across the continental United States. » 3/27/11 9:00am 3/27/11 9:00am