Neptune is the eighth and outermost planet in our solar system.
It is the fourth-largest planet by diameter and the third-largest by mass; Neptune is 17 times the mass of Earth and is slightly more massive than its near twin Uranus which is 14 Earth Masses, but slightly smaller due to its higher density.
Neptune's atmosphere is primarily composed of hydrogen and helium, with traces of methane that account for the planet's blue appearance.
Neptune's blue colour is much more vivid than that of Uranus, which has a similar amount of methane, so an unknown component is presumed to cause Neptune's intense color.
Neptune also has the strongest winds of any planet in the solar system, with estimates as high as 2,500 km/h or 1,500 mph.
Mercury (planet) Mercury is the innermost and smallest planet in the solar system, orbiting the Sun once every 88 days. It ranges in brightness from about −2.0 ... >
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Uranus Uranus is the seventh planet from the Sun. It is a gas giant, the third largest by diameter and fourth largest by mass. NASA's Voyager 2 is the only ... >
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Saturn Saturn is the sixth planet from the Sun. It is a gas giant, the second-largest planet in the solar system after Jupiter. Saturn has a prominent ... >
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Precession Precession refers to a change in the direction of the axis of a rotating object. In certain contexts, "precession" may refer to the precession that ... >
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Deimos (moon) Deimos is probably an asteroid that was perturbed by Jupiter into an orbit that allowed it to be captured by Mars, though this hypothesis is still in ... >
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Neptune's natural satellites Neptune has 13 known moons. The largest by far is Triton, discovered by William Lassell just 17 days after the discovery of Neptune itself. It took a ... >
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Phobos (moon) Phobos is the larger and innermost of Mars' two moons, and is named after Phobos, son of Ares (Mars) from Greek Mythology. Phobos orbits closer to a ... >
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Dysnomia (moon of Eris) Dysnomia, is a moon of the dwarf planet Eris. The satellite is about 60 times fainter than Eris, and its diameter is estimated to be approximately ... >
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Geosynchronous orbit A geosynchronous orbit is a geocentric orbit that has the same orbital period as the sidereal rotation period of the Earth. It has a semi-major axis ... >
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Shift of equinox The precession of the equinoxes refers to the precession of Earth's axis of rotation with respect to inertial space. The precession of the equinoxes ... >
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