Neptune planeta (old English/Latin) or planet is the most distant planet from the sun in terms of distance in the solar system. The number of Neptune is eighth in distance from the sun. In diameter, it is the fourth-largest planet. Third massive by mass and in giant planets it is the densest.
Mass And Composition of Neptune Planeta
Neptune planeta has 17 times more mass than Earth. It has slightly more mass than Uranus. Since Neptune has a greater mass so its mass causes more gravitational compression of its atmosphere and makes it denser than Uranus being physically smaller than Uranus.
It is 30.1 AU away from the sun which is equal to 4.5 billion kilometers or 2.8 billion miles. The name Neptune was given after the name of the “Roman God of Sea”.
Neptune is not visible by the naked eye. Also, it is the only planet found using mathematical predictions rather than observing through telescopes. Neptune was considered the farthest-known planet of the solar system since its discovery in 1846 until Pluto was discovered in 1930. So, after the discovery of Pluto Neptune became the second-farthest known planet in the solar system.
Neptune And It’s Neighboring Planet
Between 1979 to 1999 Pluto’s orbit brought Pluto closer to the sun than Neptune. This once again made Neptune the farthest known planet in the solar system. In 1992, after the discovery of the Kuiper belt, many astronomers debated whether Pluto is an independent planet or part of the Kuiper belt.
But, later in 2006, the International Astronomical Union for the first time defined the definition of a planet. This was the time when Pluto was given the status of a “dwarf planet” and once again Neptune became the eighth and the farthest most plane in distance from the sun.
The gravity of the Neptune planeta is 11.15 m/s2. This is more than the gravity of Earth by 1.14 times. Neptune is 17 times bigger than the Earth but comparing it to Jupiter it is only 1/19 of Jupiter. The mass of Neptune is equal to 1.0243×1026 kg. The equatorial radius is 4 times that of the earth at 24,764 km. Neptune is an ice giant like its neighbor Uranus.
The internal structure of Neptune is like that of Uranus. 5% to 10% of Neptune’s mass or maybe up to 10% towards the core is the planet’s atmosphere. The planet’s mantle which is about 10 to 15 Earth’s masses has higher concentrations of ammonia, water, and methane.
The atmosphere of Neptune contains helium and hydrogen at high altitudes. 20% of which is helium and the other 80% is hydrogen. Methane may also be present. The planet’s atmosphere has been divided into two regions. They are the “lower troposphere” and the “stratosphere”. In the troposphere, the temperature decreases as altitude decreases whereas the temperature increases when the altitude increases.
The boundary of these two regions is called the tropopause. The pressure at the tropopause is 0.1 bars which are equal to 10 kPa. After the stratosphere, the thermosphere comes where pressure becomes 10−5 to 10−4 bars. After the thermosphere, the next layer is the exosphere. Neptune is similar to Uranus in the magnetosphere.
Great Dark Spot
Neptune had a “Great Dark Spot” which was an anticyclonic storm system spread over 8.5 million kilometers. NASA’s Voyager 2 discovered the great dark spot in 1989 for the first time.
This storm was similar to Jupiter’s great red spot. On 2 November 1994, five years after the discovery of the great dark spot, Hubble telescope images did not show the storm. But a similar storm was spotted in the Northern hemisphere of the planet.
There are 14 known moons of Neptune as of today. They are called Neptunian moons. The largest Neptunian moon is Triton. William Lassell discovered Triton only after 17 days of the discovery of Neptune itself.
Neptune’s moons are divided into two groups. Regular Satellites and Irregular satellites. The regular satellites include Galatea, Despina, Proteus, Naiad, Hippocamp, Thalassa, and Larissa. The irregular satellites include Sao, Psamathe, Triton, Laomedeia, Nereid, Halimede, and Neso.
NASA’s Voyager 2 is the only spacecraft that entered into Neptune’s orbit. The spacecraft made its closest approach on the 25th of August, 1989. The presence of the magnetic field was verified in the Voyager 2 missions. Also, the spacecraft sent back images of the planet’s two major moons Triton and Nereid. At that time the signals from the spacecraft needed 246 minutes to reach the Earth.