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teman-teman,aku mau tanya,planet neptunes adalah planet air ya?berapa derajads di neptunes kalau panas dan dingin dan berapa atmoshere di situ? Huh
kayaknya sih dingin banget, francesco. karena planetnya jauh banget dari matahari.
tapi planet neptunes planet air ya?
menurutku sih itu cuma terdiri dari gas saja.
Mungkin sangat dingin hingga beku
bener itu Fariz..

Soalnya jauh dari matahari..
so,neptunes adalah planet gas ya?
yuph.. it is..
From Wikipedia, the free encyclopedia
This article is about the planet. For other uses, see Neptune (disambiguation).
Neptune [Image: 260px-Neptune_Full.jpg]
The picture shows the Great Dark Spot and its companion bright smudge; on the west limb the fast moving bright feature called Scooter and the little dark spot are visible.
Discovery date
23 September 1846[1]
[Image: 11px-Speakerlink-new.svg.png]i/ˈnɛptuːn/
Orbital characteristics[6][a]
Epoch J2000
30.33 AU
(4,540 Gm)
29.81 AU
(4,460 Gm)
Semi-major axis
30.110387 AU
(4,504.45 Gm)
Orbital period
164.8 yr
60,182 d
89,666 Neptunian solar days[3]
Synodic period
367.49 days[4]
Average orbital speed
5.43 km/s[4]
Mean anomaly
1.767975° to ecliptic
6.43° to Sun's equator
0.72° to invariable plane[5]
Longitude of ascending node
Argument of perihelion
Known satellites
Physical characteristics
Mean radius
24,622±19 km[7][/url]
Equatorial radius
24,764±15 km[7][b]
3.883 Earths
Polar radius
24,341±30 km[7][b]
3.829 Earths
Surface area
7.6183×109 km2[8][b]
14.98 Earths
6.254×1013 km3[4][b]
57.74 Earths
1.0243×1026 kg[4]
17.147 Earths
5.15×10−5 Suns
Mean density
1.638 g/cm3[4][c]
Surface gravity
11.15 m/s2[4][b]
1.14 g
Moment of inertia factor
0.23[9] (estimate)
Escape velocity
23.5 km/s[4][b]
Sidereal [url=https://en.wikipedia.org/wiki/Rotation_period]rotation period
0.6713 day[4]
16 h 6 min 36 s
Equatorial rotation velocity
2.68 km/s
9,660 km/h
Axial tilt
28.32° (to orbit)[4]
North pole right ascension
19h 57m 20s[7]
North pole declination
0.290 (bond)
0.41 (geom.)[4]
Surface temp.
1 bar level

72 K (−201 °C)[4]

0.1 bar (10 kPa)

55 K[4]

Apparent magnitude
8.02 to 7.78[4][10]
Angular diameter
Scale height
19.7 ± 0.6 km
Composition by volume

80 ± 3.2% hydrogen (H2)
19 ± 3.2% helium (He)
1.5 ± 0.5% methane (CH4)
~0.019% hydrogen deuteride (HD)
~0.00015% ethane (C2H6)
ammonia (NH3)
water (H2O)
ammonium hydrosulfide (NH4SH)
methane ice (?) (CH4•5.75H2O)

Neptune is the eighth and farthest known planet from the Sun in the Solar System. In the Solar System, it is the fourth-largest planet by diameter, the third-most-massive planet, and the densest giant planet. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times the mass of Earth and slightly larger than Neptune.[d] Neptune orbits the Sun once every 164.8 years at an average distance of 30.1 astronomical units (4.50×109 km). It is named after the Roman god of the sea and has the astronomical symbol ♆, a stylised version of the god Neptune's trident.
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. Unexpected changes in the orbit of Uranus led Alexis Bouvard to deduce that its orbit was subject to gravitational perturbation by an unknown planet. Neptune was subsequently observed with a telescope on 23 September 1846[1] by Johann Galle within a degree of the position predicted by Urbain Le Verrier. Its largest moon, Triton, was discovered shortly thereafter, though none of the planet's remaining known 14 moons were located telescopically until the 20th century. The planet's distance from Earth gives it a very small apparent size, making it challenging to study with Earth-based telescopes. Neptune was visited by Voyager 2, when it flew by the planet on 25 August 1989.[11] The advent of the Hubble Space Telescope and large ground-based telescopes with adaptive optics has recently allowed for additional detailed observations from afar.
Neptune's composition can be compared and contrasted with the Solar System's other giant planets. Like Jupiter and Saturn, Neptune's atmosphere is composed primarily of hydrogen and helium, along with traces of hydrocarbons and possibly nitrogen, but it contains a higher proportion of "ices" such as water, ammonia, and methane. However, its interior, like that of Uranus, is primarily composed of ices and rock,[12] which is why Uranus and Neptune are normally considered "ice giants" to emphasise this distinction.[13] Traces of methane in the outermost regions in part account for the planet's blue appearance.[14]
In contrast to the hazy, relatively featureless atmosphere of Uranus, Neptune's atmosphere has active and visible weather patterns. For example, at the time of the Voyager 2 flyby in 1989, the planet's southern hemisphere had a Great Dark Spot comparable to the Great Red Spot on Jupiter. These weather patterns are driven by the strongest sustained winds of any planet in the Solar System, with recorded wind speeds as high as 2,100 kilometres per hour (580 m/s; 1,300 mph).[15] Because of its great distance from the Sun, Neptune's outer atmosphere is one of the coldest places in the Solar System, with temperatures at its cloud tops approaching 55 K (−218 °C). Temperatures at the planet's centre are approximately 5,400 K (5,100 °C).[16][17] Neptune has a faint and fragmented ring system (labelled "arcs"), which was first detected during the 1960s and confirmed by Voyager 2.[18]

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