Here on Earth, we euphemistically refer to our planet as the “third rock from the Sun,” due to our position in the solar system. Way, way out is Pluto, which was the ninth rock until it was stripped of its planet status, now relegated to a mere Kuiper Belt object. So now holding up the outer edge of our solar system is Neptune, the eighth farthest planet orbiting our sun.
Other than its relative spot in our solar neighborhood, though, what do we really know about Neptune? Recent research and exploration by the Hubble Space Telescope and flybys in 1989 by the Voyager 2 NASA spacecraft have revealed much about the solar system’s third-most massive planet. At 17 times the Earth’s mass, Neptune is also the most dense of the gas giants and the fourth-largest planet in diameter. Culled from sources including nasa.gov and nineplanets.org, here are six lesser-known Neptune facts.
Neptune has 14 moons
This is kind of a tricky one, since the number has changed with continual new finds. Based on their shapes, many of these are more what you would think of as asteroids - chunky and jagged, not round like Earth’s moon. But moons are technically just satellites, so all of these count. Some of the most amazing recent discoveries in planetary science have arisen from the many moons of Neptune: Triton, Nereid, Naiad, Thalassa, Despina, Larissa, Proteus, Galatea, Laomedeia, Neso, Halimede, Psamathe, Hippocamp, and Sao.
Neptune was named for a Roman god
This is no stretch, considering how much of the original Roman mythological pantheon is used in naming space objects. In Roman myth, Neptune was the god of the sea, so the name of this deep-blue colored planet seems appropriate. The Greek equivalent is Poseidon.
Earth is blue due to oceans; Neptune’s blue is atmospheric chemistry
Neptune's composition is probably similar to its near-twin, Uranus—featuring ice and rock, with around 15% hydrogen and a little helium in its atmosphere. But, unlike its fellow gas giants Jupiter and Saturn, Neptune is not known to have a distinct internal layering, instead having what is thought to be a relatively uniform makeup surrounding a core about the mass of Earth. And with an atmosphere primarily composed of hydrogen and helium, plus a small amount of methane, Neptune's blue color is largely caused by absorption of red light by the methane. However, an additional, unidentified atomic makeup gives the planet’s clouds their shimmering, deep-blue tone.
Neptune has the fastest winds in our solar system
As is normal for gas planets such as Neptune, it has intensely powerful, high-velocity winds that whirl around the planet in specific bands of latitude. These large storms, or vortices, on Neptune produce the fastest winds in the solar system, reaching close to 1,250 miles per hour.
Neptune’s core radiates more heat than it receives from the Sun
Like the other gas giants, Neptune produces its own internal heat. This is a good thing for a planet some 2.4 billion miles from the sun. In fact, Neptune radiates from its core more than twice the amount of energy as it takes in from the far distant sun. For comparison, Earth sits about 93 million miles from the sun, and we rely on the sun for the majority of our heat, althouh some is created internally from radioactive decay and heat left over from the formation of our planet.
Neptune can be viewed through binoculars
The eighth planet will appear only as a small, yet discernible, blue disc in the night sky—if you know precisely where to look. Large telescopes provide far better detail, of course, and those of us without our own observatory can turn to the Internet. Multiple websites provide planetary chart information that tracks the whereabouts of Neptune and the other planets. One clearinghouse of both paid and free planetary software with which to pull up planetary images on your computer or device can be found at nineplanets.org.