When you're looking at the entire surface of Mars, captured from space, there are 4 huge volcanoes visible in the Tharsis region of Mars. Olympus Mons is the largest, and the other 3 are Ascraeus...
79 but none of them are active
mars has lots of valcanoes but we cant see them
lots.
there is 2 rovers on Mars right now but 1 of the rovers has not responded.go to www.nasa.gov