This image compares the height of Earth's Mount Everest with Olympus Mons,a shield volcano on Mars and the tallest mountain in the known Solar System. Olympus Mons rises to a height of 26 km above the surrounding plains,and 21 km above Mars' datum (a Martian reference point equivalent to sea level on Earth). Mount Everest,by contrast,is only 8.84 km above sea level. Indeed,Olympus Mons is so tall and wide that if you stood on it,you would not know you were on a mountain - the slope is too shallow and the mountain's rim would be over the horizon. In this image,however,Olympus Mons is shown at 1/3 of its actual width,for clarity |