Neptune: Facts about the eighth planet from the sun

Home References Science & Astronomy (Image credit: NASA) Neptune is the eighth planet from the sun in our solar system. This blue gas giant is far larger than Earth, at more than 17 times Earth's mass and nearly 58 times Earth's volume, according to NASA. Neptune's rocky core is surrounded by a slushy fluid mix…

(Image credit: NASA)

Neptune is the eighth planet from the solar in our solar gadget. This blue gas huge is a lot elevated than Earth, at extra than 17 times Earth’s mass and with regards to 58 times Earth’s volume, in accordance to NASA. Neptune’s rocky core is surrounded by a slushy fluid combination of water, ammonia and methane ice. 

Astronomer Galileo Galilei used to be one of many first of us to identify Neptune as a neighborhood object, nonetheless he assumed it used to be a huge title in accordance to its tiring motion. Around two hundred years later, in 1846, French astronomer Urbain Jean Joseph Le Verrier calculated the approximate location of Neptune by finding out gravity-prompted disturbances within the motions of Uranus, in accordance to a synopsis written by researchers at the University of St. Andrews in Scotland

At the same time Le Verrier used to be calculating the existence of Neptune, so used to be English astronomer John Sofa Adams. The two students independently came up with with regards to the same mathematical predictions about Neptune’s existence. Le Verrier then informed his colleague, German astronomer Johann Gottfried Galle, about his calculations, and Galle and his assistant Heinrich d’Arrest, confirmed Le Verrier’s predictions by viewing and figuring out Neptune by the telescope at his observatory in Berlin. 

In accordance with your total assorted planets considered within the sky, and as advised by Le Verrier, this unique world used to be given a title from Greek and Roman mythology — Neptune, the Roman god of the sea.

Connected: The most sharp mysteries about Neptune

Ideal one mission has flown by Neptune — Voyager 2 in 1989. Lately, there are peaceable many mysteries relating to the frigid, blue planet, equivalent to why its winds are so like a flash and why its magnetic subject is offset. Whereas Neptune is of hobby because it is in our fetch solar gadget, astronomers are additionally attracted to finding out extra relating to the planet to serve with exoplanet learn. Particularly, astronomers are attracted to finding out relating to the habitability of worlds which could perchance be bigger than Earth. 

Love Earth, Neptune has a rocky core, but it absolutely has a unparalleled thicker atmosphere that prohibits the existence of life as we understand it. Astronomers are peaceable looking to resolve out at what point a planet is so broad that it could possibly perchance also hold up loads of gas within the gap, making it refined or very no longer seemingly for life to exist.

What does Neptune impress like?

as-yet-unidentified compound and the final result of the absorption of crimson light by methane within the planet’s mostly hydrogen-helium atmosphere. 

Despite Neptune’s distance from the solar, which methodology it will get tiny sunlight to aid warm and drive its atmosphere, Neptune’s winds can reach as a lot as 1,500 mph (2,400 km/h), the fastest detected within the solar gadget to this point. These winds had been linked with a valuable sunless storm that Voyager 2 tracked in Neptune’s southern hemisphere in 1989. This oval-shaped, counterclockwise-spinning “Immense Darkish Disclose” used to be broad ample to bear your total Earth, and moved westward at with regards to 750 mph (1,200 km/h). The storm perceived to own vanished when the Hubble Disclose Telescope sought for it at a later date, and since then, Hubble has witnessed the looks after which fading of assorted Immense Darkish Spots on Neptune over the previous decade. 

Due to high temperatures and pressures that exist on Neptune and Uranus, scientists reflect compressed carbon within the form of diamonds causes a “diamond rain” phenomenon on these frigid giants. In 2017, researchers had been ready to simulate the necessities that could perchance reason diamonds to form within the lab, supporting the hypothesis that diamond rain occurs on Neptune and Uranus. 

Neptune is surrounded by original rings, which don’t seem to be uniform, but have vivid thick clumps of dirt known as arcs. The rings are belief to be fairly younger and quick-lived. Earth-basically based observations equipped in 2005 chanced on that Neptune’s rings are interestingly a long way extra unstable than previously belief, with some dwindling away all as we command, in accordance to an article within the journal Icarus.

Neptune’s magnetic poles are tipped to the facet by roughly 47 degrees compared with the poles along which it spins. As such, the planet’s magnetic subject, which is set 27 times extra principal than Earth’s, undergoes wild swings during every rotation.

By finding out the cloud formations on the gas huge, scientists had been ready to calculate that a day on Neptune lasts honest below 16 hours long. Neptune’s elliptical, oval-shaped orbit keeps the planet an average distance from the solar of virtually 2.8 billion miles (4.5 billion kilometers), or roughly 30 times as a long way away as Earth, making it invisible to the bare reflect. Neptune goes around the solar as soon as roughly every 165 Earth years, and done its first orbit since being chanced on in 2011.

Every 248 years, Pluto strikes internal Neptune’s orbit for 20 years or so, during which interval it is nearer to the solar than Neptune. However, Neptune stays the farthest planet from the solar, since Pluto used to be reclassified as a dwarf planet in 2006.

Neptune’s moons

Neptune has 14 acknowledged moons, named after lesser sea gods and nymphs from Greek mythology. The most sharp by a long way is Triton, whose discovery on Oct. 10, 1846, used to be circuitously enabled by beer — newbie astronomer William Lassell, who chanced on Triton, historical the funds he made as a brewer to finance his telescopes.

Hasty info about Neptune

– Atmospheric composition (by volume): 80% hydrogen, 19% helium, 1.5% methane

– Magnetic subject: Roughly 27 times extra principal than Earth’s

– Composition by mass: 25% rock, 60-70% ice, 5-15% hydrogen and helium

– Interior composition: Mantle mantle of water, ammonia and methane ices; Core of iron and magnesium-silicate

– Moderate distance from the solar: 2,795,084,800 miles (4,498,252,900 km) (that is 30.069 times farther than Earth)

– Perihelion (closest means to the solar): 2,771,087,000 miles (4,459,630,000 km) (that is 29.820 times that of Earth)

– Aphelion (farthest distance from the solar): 2,819,080,000 miles (4,536,870,000 km) (that is 30.326 times that of Earth)

(Source: NASA)

Triton is the easiest spherical moon of Neptune. The planet’s assorted 13 moons are irregularly shaped. Triton is additionally sharp in being the easiest broad moon within the solar gadget to circle its planet in a direction reverse to its planet’s rotation — this “retrograde orbit” suggests that Triton can also as soon as own been a dwarf planet that Neptune captured in desire to forming in space, in accordance to NASA. Neptune’s gravity is dragging Triton nearer to the planet, which methodology that tens of millions of years from now, Triton will reach end ample for gravitational forces to rip it apart.

Triton could be very cool, with temperatures on its ground reaching about minus 391 degrees F (minus 235 degrees C), making it one of many coldest areas within the solar gadget. However, Voyager 2 detected geysers spewing frigid subject upward extra than 5 miles (8 km), showing its internal seems warm. Scientists are investigating the chance of a subsurface ocean on the frigid moon. In 2010, scientists chanced on seasons on Triton.

Connected: What it could possibly perchance be fetch to dwell on Neptune’s moon Triton

In 2020, NASA equipped the chance of a unique space mission to search recommendation from Triton, known as Trident. “Triton has consistently been one of many most thrilling and intriguing bodies within the solar gadget,” Louise Prockter, director of the Lunar and Planetary Institute of the Universities Disclose Study Association in Houston, who leads the Trident proposal personnel, acknowledged within the observation.

In 2013, scientists working with SETI caught gape of Neptune’s “lost” moon of Naiad utilizing files from the Hubble Disclose Telescope. The 62-mile-huge (100 km) moon had remained unseen since Voyager 2 chanced on it in 1989.

Additionally in 2013, scientists utilizing the Hubble Disclose Telescope chanced on the 14th moon, dubbed S/2004 N 1. It’s miles Neptune’s smallest moon and is honest 11 miles (18 km) huge. It bought its temporary title because it is the first satellite (S) of Neptune (N) to be chanced on from shots taken in 2004, in accordance to NASA.

Extra sources and reading

To learn extra about how Neptune used to be chanced on and plans for future learn, learn Thomas Okay. Adamson’s “The Secrets of Neptune” (Capstone Press, 2015). Two broad books about Neptune for kids are Nancy Loewen’s “Farthest from the Sun: The Planet Neptune” (Portray Window Books, 2008), and Ellen Lawrence’s “Neptune: The Stormiest Planet” (Ruby Tuesday Books, 2013). 


  • O’Conner, J.J. and E. F. Robertson, 1996. “Mathematical Discovery of Planets.” University of St. Andrews Scotland.
  • NASA 2022. Solar Machine Exploration – Overview: Neptune.

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Charles Q. Choi

Charles Q. Choi is a contributing author for and Dwell Science. He covers all things human origins and astronomy as well to physics, animals and general science subject matters. Charles has a Master of Arts level from the University of Missouri-Columbia, School of Journalism and a Bachelor of Arts level from the University of South Florida. Charles has visited every continent on Earth, drinking rancid yak butter tea in Lhasa, snorkeling with sea lions within the Galapagos and even mountaineering an iceberg in Antarctica. Take a look at with him at