The Outer Planets

1
The Outer Planets
2
Saturn

• Mass 95.2 M?
• Radius 9.5 R?
• Rotation 10.5 hrs
• Orbital Period 29.5y
• Distance from Sun
• 9.5 A.U.
• of Moons 60

3
Saturn is a rapidly rotating planet like Jupiter,
but has a lower density, making the planet even
more oblate than Jupiter. The colors of Saturn
are more
subdued than those of Jupiter perhaps the
lower temperatures and lower solar radiation
makes the production of organic molecules more
difficult.
4

• The Rings of Saturn
• Very thin 5 10 km
• Radius 140,000 km
• Made of millions of tiny
• moonlets, organized into
• thousands of ringlets.
• The large gaps (Cassinis

division, Enckes division) are created by
resonance effects with some of the moons of Saturn
5
(No Transcript)
6
Density Waves in the Rings of Saturn
7
(No Transcript)
8
The F-ring of Saturn is a narrow ring. Its
narrowness is maintained by two shepherd
satellites note the braided appearance of the
ring.
9
The Cassini spacecraft is currently orbiting
Saturn (arrival date July 1, 2004). This
mission is studying the atmosphere of Saturn,
its rings, moons (the Huygens probe has landed
on Titan) and the environment of space.
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
Uranus appears almost featureless in a
telescopic view. Only computer enhancement
brings out atmospheric bands such as we see on
Jupiter.
14
(No Transcript)
15
Uranus has a system of Rings and moons. But the
most astonishing thing about Uranus is the tilt
of its rotational axis 98 degrees, which means
that it rotates on its side, so that the axis
lies almost in the orbital plane.
16
The magnetic field of Uranus is bizarre as
well It is highly inclined to the rotational
axis.
17
Neptune Was Discovered in 1846 as a result of
calculations performed by John Couch Adams
and Urbain Leverrier. These calculations success
fully accounted for deviations in the orbit of
Uranus, and predicted the position of a new
planet Neptune.
18
Neptune was visited by The Voyager II
spacecraft in 1989. Photos from Voyager revealed
Neptune to be a much more dynamic planet
than Uranus, with interesting atmospheric
features, including a great Blue Spot, and high
velocity clouds.
19
Unlike Jupiters Great Red Spot, the Great Blue
Spot of Neptune did not prove to be long-lived,
as shown by its absence in these HST photographs
taken in the mid 1990s.
20
The Interior structures of Uranus and Neptune are
quite different from those of Jupiter and Saturn.
The outer layer is composed of liquid hydrogen
and helium, followed by a layer of
highly compressed water. Finally, both planets
have quite large rocky cores.
21
Triton the great moon of Neptune
This moon shows a polar ice cap, numerous frozen
lakes of water ice, and geysers, pro- bably
powered by nitrogen gas.
22
(No Transcript)
23
Neptune also has a set of rings, like the other
Jovian planets.
24
Pluto
Pluto was discovered in 1930 By Clyde Tombaugh,
who Was working at the Lowell Observatory.
PLuto was Named in honor of Percival Lowell,
founder of Lowell Observatory.
25
Pluto is a small, icy body, orbiting at the
edge of the solar system. The above is the
most detailed map we have of Pluto. It was
derived from many individual photos taken of the
planet by the Hubble Space Telescope.
26
Pluto, surprisingly, has a large moon, discovered
in 1978 and called Charon. The diameter of the
moon is more than one-half that of Pluto.
27
(No Transcript)
28
Pluto is a small, icy dwarf planet, smaller
than our Moon. It may more properly be classed
not as a planet, but as one of the largest of
the Kuiper belt objects. Pluto is as of yet
unexplored by spacecraft. NASA has recently
launched the New Horizons Pluto-Kuiper Belt
mission, due to arrive at Pluto in July 2015.
29
2003 UB313 Now Known as Eris
The Orbit
30
(No Transcript)
31
Extra Slides
32
William Herschel discovered Uranus in the year
1781 by accident. He named it Georgis Sidis
(Georges star) after King George III. It
was later renamed to Uranus.
33
John Couch Adams, the discoverer (at least
according to the British) of Neptune.