Neptune-The Mysterious Planet

Intuduction

Neptune is the last and 8th planet in the our solar system. Neptune was named after the Roman god of the Sea. It is blue in colour and comprise of helium (19%), hydrogen (80%) and methane (1.5%). This planet is less dense than water. It has 13 natural satellites. Neptune is 17 times the mass of Earth; slightly more massive than its near-twin Uranus. It has a distance of 4.495 billion km from sun. It needs 165 years to complete one revolution around sun. It was discover by Urban Le Verrier, Johann Gottfried Galle, John Couch Adams on 23 September 1846.It is the third largest planet in the Solar System, but is much smaller than the real giants, Jupiter and Saturn. It is just a little bit bigger than Uranus.

Surface and atmosphere

The surface of Neptune is made of helium and hydrogen. It has a core of rock and ice. It has the fastest winds in the solar system up to 1300mph. As it has larger mass than Earth it also has a very high gravity. As the density of Neptune is very low if a person stand on the Neptune he would go directly to the core of rock and ice as the density is very less. There is a very amazing fact of Neptune. It rains diamonds on Neptune. When it rains, the rain water reacts with methane on the surface and forms the diamond. Due to the great force as the surface is less dense than water thus the diamond rains converts the potential energy into heat and help drive the convection that generates magnetic fields.

Formation

Neptune took shape when the rest of the solar system formed about 4.5 billion years ago, when gravity pulled swirling gas and dust in to become this ice giant. Like its neighbor Uranus, Neptune likely formed closer to the Sun and moved to the outer solar system about 4 billion years ago.

Is life possible in Neptune?

Neptune's environment is not conducive to life as we know it. The temperatures, pressures and materials that characterize this planet are most likely too extreme and volatile for organisms to adapt to.

Dreaming of blue

Orbiting at a distance of roughly 2.8 billion miles from the sun, Neptune is the furthest planet yet discovered in our solar system (that is, after Pluto's reclassification as a dwarf planet in 2006). Neptune rotates quickly compared to Earth, with one day taking 16 Earth hours. But its great distance from the sun means the years are long, requiring 165 Earth years to make one trip around our glowing star.

At such a distance from Earth, Neptune is the solar system's only planet that can't be seen in our night sky without a telescope. Even neighboring Uranus, though faint, glints overhead on a clear dark night. That means that Neptune wasn't an easy planet to discover. Some suggest that Galileo Galilei first spotted Neptune as early as 1613. Many believe that he mistook it for a star at the time, yet some scientists think that may not be the case.

Most attribute Neptune's discovery to mathematical mastery in the 1800s. After the discovery of Uranus at the turn of the century, astronomers noticed it seemed to be affected by a strange gravitational tug. This oddity led British mathematician John Couch Adams to calculate Neptune's potential position in the 1840s. A couple of years later, French astronomer Urbain Le Verrier did the same.

Frosty but hot

Neptune is just one of two ice giants in our cosmic family, along with Uranus. It's blanketed in an atmosphere of hydrogen and helium, with traces of methane, water, and ammonia. Underneath an initial chilly layer, temperatures and pressures rapidly increase.

Deep under its cloud tops, Neptune might sport a vast, roiling-hot ocean of water that envelops its rocky core. But not all scientists agree that the planet is cool enough for such liquid to stick around without evaporating.

Methane in the atmosphere reflects blue light, painting the world in vibrant color. In most pictures, Neptune seems to be a deeper and more brilliant blue than Uranus, which looks like a pale turquoise dot. But Neptune is likely similarly pale as its neighbor and just appears darker in images because of its greater distance from the sun. Still, according to NASA, there may be some other, unknown component of Neptune's atmosphere that colors the world a slightly different hue.

Celestial tagalongs

Neptune has 14 known moons as of 2019. Its largest celestial tagalong, Triton, is the solar system's only large moon that has a retrograde orbit, which means it zips around Neptune in the opposite direction than its host planet's rotation. This curious orbital direction may be evidence that it wasn't always a moon.

Instead, researchers propose Triton started as a binary system—similar to the dwarf planet Pluto and its moon Charon. As it passed by, Neptune's gravity kidnapped Triton from the pair and trapped it in orbit. Triton has a thin atmosphere that seems to be growing warmer, but scientists are unsure why.

Five known rings of rocks and dust encircle Neptune—all named after astronomers who helped bring to light details about the windy world. The ring names are Galle, Le Verrier, Lassell, Arago, and Adams. Neptune also has several partial rings, known as arcs.

Only one spacecraft has ever visited the dark blue world. Voyager 2 whipped by in 1989, collecting captivating data and images. Though many scientists have proposed additional visits, none have yet been approved.

Until another plan is crafted to visit Neptune, researchers will have to appease their curiosity from afar, capitalizing on observations from the Hubble Space Telescope as well as telescopes that have their bases firmly planted on the ground.

Neptune's Ring Arcs Found

NASA's Voyager spacecraft imaging science team has found two of the long-sought-after ring arcs, or partial rings, thought to exist around Neptune.

The arcs were found in photographs returned by the spacecraft early this morning at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The two ring arcs are apparently associated with two of the new Neptunian moons also found by Voyager 2 earlier this month. The arcs appear to wrap approximately 45 degrees and 10 degrees, respectively, in the planet's equatorial plane. One is about 50,000 kilometers (about 30,000 miles) in length; the second is about 10,000 kilometers (about 6,000 miles) long.

The first arc, the longer of the two, was seen just outside the moon 1989 N4, which orbits about 62,000 kilometers (38,500 miles) from the planet's center, or about 37,000 kilometers (23,300 miles) from the planet's cloud tops.

The second arc appears to trail the moon 1989 N3 by approximately 90 degrees, or by about 80,000 kilometers or 50,000 miles. That moon orbits Neptune at distance of about 52,000 kilometers (32,300 miles) from the center of the
planet, or about 27,300 kilometers (about 17,000 miles) from the planet's cloud tops.

Astronomers have long suspected the existence of such an irregular ring system around Neptune. Data from repeated ground-based observations hinted at the existence of disorderly strands of partial rings orbiting Neptune. Voyager's photographs of the ring arcs are the first photographic evidence that such ring system exists.

Voyager scientists said the ring arcs may be comprised of debris associated with the nearby moons, or may be the remnants of moons that have been torn apart or ground down through collisions. Close-up studies of the ring arcs by Voyager 2 in coming days should help determine their composition.

More ring arcs are expected to be found as the spacecraft nears the planet, Voyager scientists said.

Discovery of the two arcs when the spacecraft was still about 21 million kilometers (13 million miles) from Neptune gives the Voyager team time to schedule detailed photography of the ring arcs when the spacecraft comes within 4,850 kilometers (3,000 miles) of the planet August 24 and 25.

The Voyager mission is conducted by the Jet Propulsion Laboratory for NASA's Office of Space Science and Applications