Mount Everest, at 29,029 feet tall (~5.5 miles), is the tallest mountain on earth (excluding Hawaii's Mauna Kea, which is actually 33,465 feet tall -- only 13,796 of which are above sea level). But it's got nothing on the tallest mountain in the solar system. Nope, Mars's Olympus Mons (not to be confused with mons pubis, the female vagina mound), takes the award at a staggering 14 miles tall. Pfft, I could hike it. I never would because I'm lazy and hate even taking the stairs, but I could.
Olympus Mons is said to have reached such staggering heights the same way volcanoes form here on Earth -- minus one critical difference. Mars doesn't have plate tectonics. So instead of shifting over time to create a mountain range, Olympus Mons probably sat over a volcano-forming "hot spot" for a really long time.
Oh you think you're sooooo special just because you have the tallest mountain in the solar system, do you, Mars? Too bad it looks like a frostbit zombie nip! BURN -- earth's tits are way sweeter!