Olympus Mons vents over a long period of time (The Hawaiian Islands exemplify similar shield volcanoes on a smaller scale – see Mauna Kea). Like the basalt volcanoes on Earth, Martian basaltic volcanoes are capable of erupting enormous quantities of ash. Due to the reduced gravity of Mars compared to Earth, there are lesser buoyant forces on the magma rising out of the crust. In addition, the magma chambers are thought to be much larger and deeper than the ones found on Earth. The flanks of Olympus Mons are made up of innumerable lava flows and channels. Many of the flows have
Fictional planets of the Solar System a "tenth planet". Since 1992, a very large number of objects have been found beyond Neptune; all the objects in the following list, however, are purely fictional. Common names for trans-Neptunian planets in fiction include Planet X, after a planet once believed to lie beyond Neptune, and Persephone (or Proserpina), after the wife of Pluto. Rogue planets in fiction usually originate outside the Solar System, but their erratic paths lead them to within detectable range of Earth. In reality, no rogue planet has ever been detected transiting the Solar System. Fictional planets of the Solar System The fictional portrayal of