Neptune

The Sea King Star as Neptune is known in China, remained undiscovered all throughout the centuries until the invention of the telescope. Even then this, the eighth planet in our solar system, was thought to be a star when observed by Galileo. It is the first planet whose discovery was made by predicting its location with mathematics.

A Look at Neptune

The name for the eighth planet of the solar system seems all the more appropriate when one gets a good look at its colour- as Neptune is the name of the Greek god of the sea. The deep, vivid blue of Neptune is thought to come from the methane in its atmosphere, although an unknown component makes it more vivid that Saturn, which has roughly the same amount of methane.

Neptune can never be seen with the naked eye, which explains why it was never discovered, or observed at all, until Galileo marked it down on his star charts. Because its motion was too slight to notice at the time, it was considered a star, and so Galileo is not credited with Neptune’s discovery. In 1821 published charts of Uranus’ orbit provided the first clues to Neptune’s existence. John Couch Adams in 1843 produced calculations that called for an eight planet to be the source of Uranus perturbing, but he had trouble getting colleagues to help him with the verification. Independent of this Urbain Le Verrier produced similar calculations in 1846, but also had trouble getting assistance.

Finally on, September 23, 1846 student Johann Gottfried Galle, along with Verrier, discovered Neptune. Incredibly it was found within one degree of its predicted location by Verrier, and ten degrees off form where Adams said it would be.

Neptune, Ice Giant

Neptune is a gas giant, insofar as it is not a rocky, terrestrial planet. It is, however, different enough in make up from Saturn that it is in a sub classification known as an ice giant, along with Uranus. It has a core thought to be of molten rock that burns hotter than the surface of the sun, yet its “surface” temperature is very cold, due to its distance from the sun. As a gas planet there is little distinction between atmosphere and surface, and the bulk of Neptune’s composition is swirling hydrogen and helium gas, with plenty of methane as well.

The planet is about 17 times more massive than Earth and is the fourth largest planet in the solar system by diameter. The temperature at its cloud tops is the coldest in the solar system at about -218 degrees centigrade, yet its internal heat is immense. This is one of the many curiosities about the planet, along with its vivid blue colour and the “great dark spot” in the southern hemisphere that drive scientific investigation of Neptune.

The only visit to the eighth planet so far has been Voyager 2, which flew by Neptune in 1989. Neptune has 13 moons, but only one that is big enough to be spheroid in shape, Triton.

Final Thoughts

Neptune, as the furthest planet in our solar system from Earth, remains the least understood. Take, for example, the winds on the planet. It was believed that the further a planet from the sun, the less energy there would be to push winds around, yet on Neptune some of the fastest winds in the solar system are found; yet another puzzle waiting to be solved.

Related Articles in the 'The Planets' Category...

• All About The Earth
• ISS Assembly Sequence
• Jupiter
• Mars
• Planet Mercury
• Planet Venus
• Planets Outside the Solar System
• Pluto
• Saturn
• Uranus