The outer planets are those planets in the Solar System beyond the asteroid belt, and hence refers to the gas giants, which are in order of their distance from the Sun:
- Jupiter is the largest planet in the Solar System, with distinct bands and four very large satellites.
- Saturn is the second largest planet, with a large and bright ring system.
- Uranus was discovered in 1781. It is tilted almost onto the plane of its orbit.
- Neptune was discovered in 1846 as a result of its perturbations of Uranus.
The outer planets all have ring systems, although all but Saturn's are faint.
Another aspect common to the gas giants is their many natural satellites, two of which are larger than the planet Mercury (Jupiter's Ganymede and Saturn's Titan). That pair and Io, Callisto, Europa, and Triton, are larger than Pluto and Eris.
This region of space is also occupied by centaurs, various fields of trojans, and many comets.
Pluto was considered to be an outer planet from its discovery in 1930 until its reclassification as a dwarf planet in 2006 (see also Kuiper belt).
... Chaos was an entirely fictional tenth planet (also known as Planet X) of the Solar System composed primarily of dark matter ...
... Project LONGSTOP (Long-term Gravitational Study of the Outer Planets) was a 1982 international consortium of Solar System dynamicists led by Archie ... a supercomputer, integrating the orbits of (only) the outer planets ... several curious exchanges of energy between the outer planets, but no signs of gross instability ...
... According to the nebular hypothesis, the outer two planets are in the "wrong place" ... The migration of the outer planets is also necessary to account for the existence and properties of the Solar System's outermost regions ... At their distance from the Sun, accretion was too slow to allow planets to form before the solar nebula dispersed, and thus the initial disc lacked enough mass density to ...
... flowers representing different zones of the giant gas planet however, there are plans to build a 3D model ...
Famous quotes containing the words planets and/or outer:
“Marriage is the clue to human life, but there is no marriage apart from the wheeling sun and the nodding earth, from the straying of the planets and the magnificence of the fixed stars.”
—D.H. (David Herbert)
“The guarantee that our self enjoys an intended relation to the outer world is most, if not all, we ask from religion. God is the self projected onto reality by our natural and necessary optimism. He is the not-me personified.”
—John Updike (b. 1932)