Mars rotates on its axis every 24.6 Earth ... The highlands of the southern hemisphere, however, are studded with many extinct volcanoes, and the crust there can get up to 62 miles thick.

As Mars’ polar ice caps warm up ... There’s Olympus Mons—the largest extinct volcano in the Solar System, which is roughly ...

The answer is Olympus Mons on Mars. Yes. The hill of Arthur’s Seat ... What is the difference between a dormant and an extinct volcano? A dormant volcano is one that is not currently erupting ...

The Popa langur -- named for an extinct volcano home to its largest population, some 100 individuals -- has been around for at least a million years, according to a study detailing the find ...