NEPTUNE

By Robert, Alexis, and Arleth

Discovery

Neptune was discovered September 23rd, 1846.

The time is takes for Neptune to circle around the sun once (orbital period) is 165 years.

The length of their average day is 16 hours and 6 minutes.

Neptune

Neptune is the eighth and farthest planet from the Sun in the Solar System. It is the fourth-largest planet by diameter and the third-largest by mass. Among the gaseous planets in the Solar System, Neptune is the most dense.

Location of Neptune The planet Neptune was mathematically

predicted before it was directly observed. After it was discovered, it turned out it

had been observed many times before but not recognized. There were others who made various calculations about its location, which did not lead to its observation.

Earlier observations

Neptune is invisible to the naked eye as it is too dim.

There is evidence that Neptune was seen and recorded by Galileo Galilei in 1613, Jérôme Lalande in 1795 and John Herschel in 1830, but none is known to have recognized it as a planet at the time.

Neptune’s moon discovery

Neptune's largest moon, Triton, was discovered at the same time as the planet. Another satellite, Nereid, wasn't found until 1949. The other six were spotted by Voyager II during its flyby in 1989. A lot of research has been done on Triton, and there is evidence that life may have existed there at one time.

Neptune’s Atmosphere

Neptune’s atmosphere is made up mostly of hydrogen, helium, and methane.

The upper atmosphere of Neptune contains some white clouds of frozen methane.

Neptune has an average cloud-top temperature of about -225 C.

At a speed of 1,000 km/h, Neptune has the strongest winds in the Solar System.

Moons

William Lassell spotted Triton on 10 October 1846 -- just 17 days after a Berlin observatory discovered Neptune. It is the largest moon Neptune has and the farthest. Dutch-American astronomer Gerard Kuiper (for whom the Kuiper Belt was named) found Neptune's third-largest moon, Nereid, in 1949. He missed Proteus, the second-largest, because it's too dark and too close to Neptune for telescopes of that era.

Moons

Proteus and five other moons had to wait for Voyager 2 to make themselves known. All six are among the darker objects found in the solar system. Astronomers using improved ground-based telescopes found more satellites in 2002 and 2003, bringing the known total to 13.

Triton

Voyager 2 revealed fascinating details about Triton. Part of its surface resembles the rind of a cantaloupe. Ice volcanoes spout what is probably a mixture of liquid nitrogen, methane and dust, which instantly freezes and then snows back down to the surface. Triton's icy surface reflects so much of what little sunlight reaches it that the moon is one of the coldest objects in the solar system, about -400 degrees Fahrenheit (-240 degrees Celsius).

Rings

The rings of Neptune consist primarily of five principal rings and were first discovered (as "arcs") in 1984.

At their densest, they are comparable to the less dense portions of Saturn's rings but much of Neptune's ring system is quite tenuous, faint and dusty, more closely resembling the rings of Jupiter.

Internal Observation

The mantle is equal to 10 to 15 Earth masses and is rich in water, ammonia and methane. The core of Neptune is composed of iron, nickel and silicates, with an interior model giving a mass about 1.2 times that of Earth.

The Mysterious Dark Spot

In 1989, the Great Dark Spot, an anti-cyclonic storm system was discovered by NASA's Voyager 2 spacecraft. The storm resembled the Great Red Spot of Jupiter. Some five years later, on 2 November 1994, the Hubble Space Telescope did not see the Great Dark Spot on the planet. Instead, a new storm similar to the Great Dark Spot was found in the planet's northern hemisphere.

Orbital Period

Because Neptune is not a solid body, its atmosphere undergoes differential rotation. The wide equatorial zone rotates with a period of about 18 hours, which is slower than the 16.1-hour rotation of the planet's magnetic field. By contrast, the reverse is true for the polar regions where the rotation period is 12 hours.

http://www.cleanvideosearch.com/media/action/yt/watch?videoId=EmUvTH7sveg

As you can see, Earth is no comparison to Neptune’s mass and size.