Neptune: The Last Gas Giant Andrew Bentley

The Numbers Neptune has a diameter of 49,532 Km around its equator Neptune’s orbit is located 4,504,000 Km from the sun Since Pluto was Kicked out this makes it the farthest planet from the sun.

Discovery of Neptune Neptune was discovered on September 23, 1846 by Galle and D’Arrest Two centuries before Galileo had viewed Neptune on is own After the discovery of Uranus it was found that something was interfering with its orbit The name Neptune came from Poseidon (Greek god of the oceans)

What its made of Most of our information about Neptune comes from one spacecraft mission-The Voyager 2 The composition of Neptune is probably similar to that of Uranus --Various forms of “Ice” --Rocks consisting of about 15% hydrogen and small amounts of helium --may have direct internal layering but a less uniform chemical composition

Continued Most likely has a small core of rocky material Atmosphere made mostly of Hydrogen and Helium and a small amount of Methane The methane's absorption of Red light gives the planet its blue tint. Neptune also has an internal heat source as it radiates twice as much energy as it absorbs from the sun Neptune video

On Neptune Like the average “Gas Giant” it has strong winds that are mostly refined to latitude lines—The fastest in the solar system Neptune’s southern hemisphere is also home to the “Great Dark Spot” Another spot was discovered in the northern hemisphere. This means Neptune's atmosphere changes often There is also an odd white cloud that zips around the planet every hours or so

On Neptune (cont.) If Neptune were hollow it would contain nearly 60 Earths A Neptunian year is equal to 165 Earth years A Neptunian day last a little over 16 hours

Neptune’s Moons Neptune has 13 known moons 8 named moons and 5 that are yet to be named The moons are: --Naiad --Thalassa --Despina --Galatea --Larissa --Proteus --Triton --Nereid

Neptune’s moons (Cont.) Radius (km) Mass (kg) Discoverer Date Naiad 29 ? Voyager 2 1989 Thalassa 40 Despina 74 Galatea 79 Larissa 104x89 Proteus 200 Triton 1350 2.14e22 Lassell 1846 Nereid 170 Kuiper 1949

Neptune’s Rings Neptune also has rings that appear to only be faint arcs Neptune’s rings are: --Diffuse --Inner --Plateau --Main

Triton Discovered by Lassell in 1846 One of the only volcanically active bodies in the solar system Seasonal heating from the sun causes eruptions of liquid nitrogen, dust and methane The surface of Triton is only 34.5K at this temperature methane, nitrogen, and carbon dioxide all freeze The surface also has few craters, inferring that the crust is relatively young. It is also the largest moon to revolve backward around its planet

Triton (cont.) Triton with Neptune on the horizon The surface is made of 25% ice and the rest icy material

Triton (Cont.) Triton is believed to have formed in the Kuiper Belt Believed that it was speeding past Neptune when it was captured by its gravitational pull. The backward revolution slows the moon eventually causing it to either fall apart forming a ring or crash into the planet itself

Coolish Stuff http://pds.jpl.nasa.gov/planets/captions/neptune/Idspot.htm http://www.dailymotion.com/video/x3io_the-nine-planets-neptune_travel

Sources Arnet, Bill “Neptune” September 2, 2004 www.nineplanets.org/neptune.html www.solarviews.com/eng/neptune.htm