Olympus Mons on Mars is 15.5 miles high. Compare this to Mt. Everest here on earth, at roughly 5.5 miles high. That’s quite a difference!
Earth makes it onto the list (tallest mountains in the solar system) at number 10- Mauna Loa in Hawaii. While Mt. Everest is the tallest mountain on earth relative to sea level, Mauna Loa clocks in at above 30,000 feet when you consider it from base (under water) to it’s peak at 16,400 feet above sea level (counting from sea level up!). This is an impressive list! Check out the below link for the original article:
And THIS link for more on Mauna Loa (below).