Tag Archives: Neptune

Neptune is the eighth and farthest known planet from the Sun in the Solar System. It 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. 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. Neptune orbits the Sun once every 164.8 years at an average distance of 30.1 astronomical units (4.50×109 km). Named after the Roman god of the sea, its astronomical symbol is ♆, a stylized 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 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. 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 is similar in composition to Uranus, and both have compositions that differ from those of the larger gas giants, Jupiter and Saturn. Like Jupiter and Saturn, Neptune’s atmosphere is composed primarily of hydrogen and helium, along with traces of hydrocarbons and possibly nitrogen, but 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, and hence Uranus and Neptune are normally considered “ice giants” to emphasise this distinction. Traces of methane in the outermost regions in part account for the planet’s blue appearance.

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). 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). Neptune has a faint and fragmented ring system (labelled “arcs”), which was first detected during the 1960s and confirmed by Voyager 2.

Neptune-Earth Size Comparison

Source: wikipedia

Scale of the Solar System (and the first flybys of planets)

Previously I posted two articles titled “If The Moon Were Only 1 Pixel – A Tediously Accurate Map Of The Solar System“, and “A Scale Model of Solar System Drawn in the Desert and the Result is Stunning“. Since the human brain cannot deal with the really large numbers, these articles provide an amazing way to understand how big actually our Solar System is.

Now, I decided to put the Solar System into scale as an infographic. You can see a scaled Solar System below, the planets’ distances from the Sun, and the first flybys over them. Plus some statistics about the planets and our home planet, the Earth.
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Planet Nine – Where is it?

In January 2015, Caltech (California Institute of Technology) astronomers Konstantin Batygin and Michael E. Brown published an article titled Evidence For A Distant Giant Planet In The Solar System, and announced calculation-based evidence of a massive ninth planet. Despite they have had started their research to demonstrate that there’s no ninth planet, they reached the exact opposite result: there must be a ninth planet beyond Pluto, and it’s probably 10 times the mass of Earth (for comparison, Neptune has 17 times as much mass compared to the Earth).
Continue reading Planet Nine – Where is it?

Astronomers Think They’ve Found Evidence for a Ninth Planet Beyond Pluto – And It’s a Giant!

Astronomers now think there’s a ninth planet in the solar system almost certainly. The farthest planet from our Sun is probably a giant, smaller than Neptune but likely larger than the Earth. It is informally called Phattie, but commonly known as Planet Nine.
Continue reading Astronomers Think They’ve Found Evidence for a Ninth Planet Beyond Pluto – And It’s a Giant!