Transcript Neptune: The Last Gas Giant

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.
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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)
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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
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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
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Neptune’s moons (Cont.)
moon
Radius
(km)
Mass
(kg)
Discover
er
Date
Naiad
29
?
Voyager
2
1989
Thalassa
40
?
Voyager
2
1989
Despina
74
?
Voyager
2
1989
Galatea
79
?
Voyager
2
1989
Larissa
104x89
?
Voyager
2
1989
Proteus
200
?
Voyager
2
1989
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
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Triton
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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.)
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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
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Coolish Stuff
http://pds.jpl.nasa.gov/planets/captions/ne
ptune/Idspot.htm
 http://www.dailymotion.com/video/x3io_the
-nine-planets-neptune_travel
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Sources
Arnet, Bill “Neptune” September 2, 2004
 www.nineplanets.org/neptune.html
 www.solarviews.com/eng/neptune.htm
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