1. Neptune: The Last Gas Giant
Andrew Bentley

2. 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.

3. 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)

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

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

11. 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

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

13. 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

14. Coolish Stuff

15. Sources Arnet, Bill “Neptune” September 2, 2004