Mons Huygens Moon further north, which was visited by Apollo 15. The tallest mountain known in the Solar System is in Rheasilvia crater on the asteroid Vesta, which contains a central mound that rises high; Olympus Mons on Mars is nearly the same height, at high. In comparison, Mount Everest rises to altitude above sea level (asl), but is only (base-to-peak) (btp). Africa's Mount Kilimanjaro is about altitude above sea level to the Uhuru peak; also 4.6 km base-to-peak. America's Denali, also known as "Mount McKinley", has a base-to-peak of . The Franco-Italian "Mont Blanc/Monte Bianco" is in altitude above sea level,
Fictional planets of the Solar System fragments of a single planet was gradually abandoned over the course of the middle decades of the 20th century in favor of the conclusion that no planet had ever accreted in the region of the asteroid belt in the first place. In fiction, various other names were given to the same or similar concepts. Fictional planets in our Solar System beyond the orbit of Neptune have been employed many times as settings or references in science fiction. Following the general reception of Pluto as the ninth planet of the Solar System in 1930, a hypothetical additional planet was sometimes called