Search results
Results From The WOW.Com Content Network
Earth is unique among the rocky planets in the Solar System in having oceans of liquid water on its surface. [2] Liquid water, which is necessary for all known forms of life , continues to exist on the surface of Earth because the planet is at a far enough distance (known as the habitable zone ) from the Sun that it does not lose its water, but ...
The Solar System is believed to have formed according to the nebular hypothesis, first proposed in 1755 by Immanuel Kant and independently formulated by Pierre-Simon Laplace. [2] This theory holds that 4.6 billion years ago the Solar System formed from the gravitational collapse of a giant molecular cloud. This initial cloud was likely several ...
A planetary surface is where the solid or liquid material of certain types of astronomical objects contacts the atmosphere or outer space. Planetary surfaces are found on solid objects of planetary mass, including terrestrial planets (including Earth), dwarf planets, natural satellites, planetesimals and many other small Solar System bodies ...
The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System. It is mostly made of molecular hydrogen and helium in roughly solar proportions; other chemical compounds are present only in small amounts and include methane, ammonia, hydrogen sulfide, and water. Although water is thought to reside deep in the atmosphere, its ...
A planetary core consists of the innermost layers of a planet. [1] Cores may be entirely liquid, or a mixture of solid and liquid layers as is the case in the Earth. [2] In the Solar System, core sizes range from about 20% (the Moon) to 85% of a planet's radius .
An artist's concept of a planetary system. A planetary system is a set of gravitationally bound non-stellar bodies in or out of orbit around a star or star system.Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals [1] [2] and ...
The Solar System [d] is the gravitationally bound system of the Sun and the objects that orbit it. [11] It formed about 4.6 billion years ago when a dense region of a molecular cloud collapsed, forming the Sun and a protoplanetary disc.
If the planet is too small, then its gravity isn't strong enough to hold onto all of the gas it gained during formation. This causes the primary atmosphere, which is mostly made of hydrogen (H 2) from the nebula the solar system formed in, [2] to run away and leave the planet entirely. Hydrogen, being the lightest element, will naturally escape ...