Are there Oceans on Other Planets?

Ocean planets are planets formed in the outer solar system. Their initial material composition resembles a comet, including water and rocks of nearly equal mass. The oceans on this type of planet may be thousands or hundreds of kilometers deeper than the oceans on Earth.

Ocean planet

In the deeper regions of the ocean planets, huge pressures

"Usually refers to terrestrial rock-like planets (such as Earth) or" sea planets "that completely cover hundreds of kilometers of ice or liquid water (such as Jupiter's icy moon Europa). In order to achieve habitability In nature, light green planets must orbit the "habitable zone" of their star. This space region is neither hot nor cold. If the planet is too far away from the star, they will freeze. If they are too close to the star, they will generate steam in the atmosphere. Flow, attracting heat to evaporate more water, leading to an out-of-control greenhouse effect that can boil all oceans on the planet's surface, which looks like the surface of Venus. Eventually, planets like this will be extremely hot, forcing water vapor to rise to At high altitude, it is separated into oxygen and hydrogen under the action of ultraviolet light. After the hydrogen escapes into space, oxygen may react with the surface of the hot planet and enter the mantle. Over time, the planet s atmosphere will lose all water .

According to planetary scientist Kevin Zahnle of NASA Ames Research Center, the desert planets in the science fiction "Sand Dunes" do not have a large amount of water on the surface like light green planets, and there is no ocean on the surface of such a planet. , But has a vast arid desert, which may be scattered scattered oasis. A desert planet called "Arakis" in Dune is described as a terrestrial planet that can nurture life.