25 Facts About Neptune


Neptune is the eighth planet from the Sun and the farthest known solar planet.

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Neptune is denser and physically smaller than Uranus because its greater mass causes more gravitational compression of its atmosphere.

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Neptune is not visible to the unaided eye and is the only planet in the Solar System found by mathematical prediction rather than by empirical observation.

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However, similar to Uranus, its interior is primarily composed of ices and rock; Uranus and Neptune are normally considered "ice giants" to emphasise this distinction.

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In contrast to the hazy, relatively featureless atmosphere of Uranus, Neptune's atmosphere has active and visible weather patterns.

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Neptune has a faint and fragmented ring system, which was discovered in 1984, then later confirmed by Voyager 2.

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In Roman mythology, Neptune was the god of the sea, identified with the Greek Poseidon.

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In Mongolian, Neptune is called, reflecting its namesake god's role as the ruler of the sea.

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When Pluto was discovered, it was considered a planet, and Neptune thus became the second-farthest known planet, except for a 20-year period between 1979 and 1999 when Pluto's elliptical orbit brought it closer than Neptune to the Sun.

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Neptune, like Uranus, is an ice giant, a subclass of giant planet, because they are smaller and have higher concentrations of volatiles than Jupiter and Saturn.

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Core of Neptune is likely composed of iron, nickel and silicates, with an interior model giving a mass about 1.

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Neptune's atmosphere is subdivided into two main regions: the lower troposphere, where temperature decreases with altitude, and the stratosphere, where temperature increases with altitude.

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Models suggest that Neptune's troposphere is banded by clouds of varying compositions depending on altitude.

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High-altitude clouds on Neptune have been observed casting shadows on the opaque cloud deck below.

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Neptune's spectra suggest that its lower stratosphere is hazy due to condensation of products of ultraviolet photolysis of methane, such as ethane and ethyne.

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The stratosphere of Neptune is warmer than that of Uranus due to the elevated concentration of hydrocarbons.

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Neptune resembles Uranus in its magnetosphere, with a magnetic field strongly tilted relative to its rotational axis at 47° and offset at least 0.

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Neptune is not a solid body, its atmosphere undergoes differential rotation.

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Neptune's orbit has a profound impact on the region directly beyond it, known as the Kuiper belt.

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Objects in this resonance complete 2 orbits for every 3 of Neptune, and are known as plutinos because the largest of the known Kuiper belt objects, Pluto, is among them.

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Some Neptune trojans are remarkably stable in their orbits, and are likely to have formed alongside Neptune rather than being captured.

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Neptune has a planetary ring system, though one much less substantial than that of Saturn.

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Earth-based observations announced in 2005 appeared to show that Neptune's rings are much more unstable than previously thought.

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Neptune may continue to brighten as it approaches perihelion in 2042.

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Neptune is currently entering its spring and summer season and has been shown to be heating up, with increased atmospheric activity and brightness as a consequence.

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