Transcript Foundation 1 - Discovering Astronomy

Chapter 7
The Outer Planets
What do you think?
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Is Jupiter a “failed star” or almost a star?
What is Jupiter’s Great Red Spot?
Does Jupiter have continents and oceans?
Are the rings of Saturn solid ribbons?
Besides being the
largest planet,
Jupiter is probably
best known for its
Great Red Spot - a
hurricane-like storms
that has been
observed ever since
the invention of the
telescope.
Jupiter’s rotation
helps create
colorful global
weather patterns
Jupiter’s rotation helps create colorful global weather patterns
Jupiter’s Chemistry
• 86% hydrogen
• 13% helium
• 1% stuff
– methane CH4
– ammonia NH3
– water vapor H2O
The light zones are regions of hotter, rising gas, while
the dark belts are regions of cooler, descending gas.
Jupiter’s interior has three
distinct regions
• Upper atmosphere of clouds and gas
• Middle layer of liquid metallic hydrogen
• Small rocky protoplanet core
Pieces of Comet Shoemaker-Levy 9
fragments collided with Jupiter in 1994
Jupiter is orbited by four large
moons and tens of small ones
Io’s surface is sculpted by volcanic activity
Io’s surface is sculpted by volcanic activity
Europa may
harbor liquid
water below
its surface
Ganymede is larger that Mercury
Callisto wears
the scars of a
huge asteroid
impact
Saturn’s banded
surface and
layered interior are
similar to those of
Jupiter
Saturn’s spectacular rings are
composed of fragments of ice and
ice-coated rock
Moons Pandora and Prometheus act as shepherd moons and keep the
F ring to a band about 100km wide because of gravitational effects.
Dust spokes in
Saturn’s rings
Titan is Saturn’s largest moon
Titan has a thick,
opaque
atmosphere rich
in nitrogen,
methane and other
hydrocarbons
(including ethane,
acetylene, ethylene,
and propane)
A system of rings and
satellites revolves
around Uranus
Uranus sports a
hazy atmosphere
with few clouds
Uranus’
odd moon
Miranda
Uranus’ tilt gives it very
exaggerated seasons
Uranus and Neptune have similar
interiors
Neptune’s
Rings
Neptune’s largest moon, Tritan, was
probably captured by Neptune’s gravity
And then, there
is one planet
unlike any of the
others …..
Pluto was discovered in 1930 by Clyde
Tombaugh by comparing photographs
taken a few days apart.
Pluto and its moon,
Charon, are about the same
size
What did you think?
• Is Jupiter a “failed star” or almost a star?
Jupiter has 75 times too little mass to shine as a star.
• What is Jupiter’s Great Red Spot?
The Great Red Spot is a long-lived hurricanelike storm.
• Does Jupiter have continents and oceans?
Jupiter is completely enveloped in a sea of liquid hydrogen
and helium
• Are the rings of Saturn solid ribbons?
Saturn’s rings are all composed of thin, closely spaced
ringlets consisting of particles of ice and ice-coated
rocks. If they were solid ribbons, Saturn’s gravitational
tidal force would tear them apart.
Self-Check
1: Name and describe the visible features in the Jovian atmosphere.
2: Sketch and label the major elements of the ring system of Saturn and describe its
composition.
3: Compare and contrast the atmospheres of Jupiter and Saturn.
4: Compare and contrast the internal structures of Jupiter and Saturn with that of Uranus
and Neptune.
5: Compare and contrast the ring systems of the outer planets.
6: Compare and contrast the atmospheric features of Uranus and Neptune.
7: Describe the geologic activity observed on Io and explain the probable origin of this
activity.
8: Compare and contrast the inner and outer Galilean satellites in terms of internal
structure and surface features.
9: List the gases that compose Titan’s atmosphere and discuss the possibility of the
existence of life forms there.
10: Compare and contrast the Voyager 2 observations of Triton with those of Titan in
terms of atmospheric composition and surface features identified.
11: Describe the physical properties of Pluto in the context of planetary classification.