December 29, 2023

Sylvie Pagovich

11th Grade

Ramaz Upper School

Neptune is the eighth and farthest planet in our solar system, located about 2.8 billion miles away from the sun. Neptune is named after the Roman god of the sea. The planet was discovered in 1846 by Johan Galle and Heinrich Louis d’Arrest. Urbain Jean-Joseph Le Verrier is also credited with the discovery because of his mathematical involvement. Neptune is the first planet to be predicted before its time using mathematics. Neptune was explored by the NASA mission Voyager Two, along with Jupiter, Saturn, and Uranus. Voyager Two discovered many things about Neptune, including five of its moons, several ring arcs, the great dark spot, four rings, and its magnetic field. 

Neptune has a similar composition to other planets: hydrogen, helium, water, and other volatiles. Neptune doesn't have a solid surface. Its atmosphere is made up of hydrogen, helium, and methane, which gives Neptune its blue color. Most of Neptune’s mass comes from a hot dense fluid of icy fluids which includes water, methane, and ammonia. These melted ices make Neptune the densest of the giant planets (a planet much larger than Earth). Neptune is considered an ice giant — a very cold, dark, and windy planet — with temperatures dropping to 72 Kelvin (-330 degrees Fahrenheit) and winds up to 1,300 miles per hour. It’s the coldest planet in our solar system. 

Neptune is surrounded by 14 moons. Triton, Neptune’s largest moon, orbits Neptune in a retrograde orbit, which is orbiting the planet in the opposite direction that it rotates in. Triton is very cold, with temperatures at -391 degrees Fahrenheit. Of Neptune’s fourteen discovered rings, the planet has five main rings and four prominent ring arcs. These rings are thought to be short-lived and are extremely difficult to see. They are composed of dark materials, likely to be organic compounds. 

To complete a full orbit around the sun takes about 165 years on Neptune. The planet has only completed a full orbit once since its discovery. One day on Neptune can take about 16 hours. Neptune is about 30 Astronomical units (Au) away from the sun. One Au is the distance between Earth and the Sun. Because of Neptune’s distance, it’s the only planet that can’t be seen with the naked eye. 

Neptune has a great dark spot, which is a large storm. It’s a dark vortex in Neptune’s atmosphere. It has high pressure and bright companion clouds. Companion clouds form when the surrounding air is diverted upward over the dark vortex, which causes the gases to freeze. 

A magnetic field is a force field that surrounds a planet and deflects the charged particles from the sun. Neptune’s magnetic field is tilted from its axis about 47 degrees. The magnetic field of Neptune is about 27 times more powerful than Earth. Inside the magnetic field are protons and electrons. The magnetosphere is the area of space that contains Neptune’s magnetic field and those charged particles. Because Neptune’s magnetic field is on a tilt, the particles in the magnetosphere are continuously glided by the rings and moons of Neptune, which gets rid of a huge number of Neptune’s charged particle content. As a result of this, Neptune’s magnetosphere has the least amount of charged particles per unit volume than any other giant planet. The charged particles in the magnetosphere can move along magnetic field lines into the atmosphere close to the magnetic poles. They cause the gases there to glow as they collide with them, producing the traditional, albeit feeble, auroras.