Transcript Jovian Planet notes

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3rd brightest object in night sky
Alternating light & dark bands
Giant Red Spot
Galilean moons (Io, Callisto,
Ganymede, Europa)
• Much fainter than Jupiter;
twice the distance from Earth
• Atmospheric bands less
distinct
• Moons
• Ring system
Voyager 1 and Voyager 2
• Launched in 1977
• Arrived at Jupiter in 1979
• Both visited Saturn
• Voyager 2 flew by Uranus and
Neptune
Galileo
• Launched in 1989
• Arrived at Jupiter in 1995
• Orbited Jupiter and its moons
• Was crashed into Jupiter in 2003
Cassini- Huygens
• Launched in 1997
• Arrived at Saturn in 2004
• Launched the Huygens probe
which landed on Titan
• Continues to orbit Saturn and
its moons
• Uranus was discovered in 1781 by
William Herschel
• Originally named after King George
III
• After some study, the predicted and
observed position of Uranus were
off. This led to the search and
discovery of…
Neptune
• Discovered in 1846 by
Johann Galle
• Neptune is not visible to
the naked eye
• Due to the composition of the
planets (gas) the equator rotates at
a different rate than near the poles
• Jupiter’s equator rotates at 9h50m,
higher latitudes are 6 minutes
slower
• Produces an oblate shape
Extra-solar Planets
• 318x more massive than Earth
• Diameter is 11x Earth’s
• 3° axial tilt
• Distance from Sun: ~5 A.U.
• Gravity = 2.53x Earth’s
• Orbital Period: ~12 earth
years
Composition:
•Molecular hydrogen (H2)
•Helium
•Trace amounts of CH4, NH3
and H2O
The Great Red Spot
•A large hurricane-like storm
that has been around for
over 300 years
•Two earths could fit inside
Belts and Zones
•Belts are the dark colored
bands
•Zones are the light colored
bands
•Caused by convection
currents
Where does the energy come
from?
• Sun’s radiation (small)
• Lightning discharges (small)
• Internal heat source*
*Jupiter gives off more than it
gets from the Sun
In 1994 Comet
ShoemakerLevy (22 pieces
of it) smashed
into Jupiter
leaving the
dark spots
seen in this
photo
•95x more massive than Earth
•9.5x Earth’s radius
•27 axial tilt
•Distance from Sun: 9.5 A.U.
•Orbital Period: 29 years
•Gravity: 1.1x Earth’s
Gases:
• Molecular Hydrogen (H2): 92%
• Helium: 7.4%
• Some of the helium liquefied and
sank to interior
• Trace amounts of CH4 and NH3
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Rings are wide but thin
About 106,000 km wide
Thickness of rings: a few hundred meters
Composition mainly water, ice, and carbon
compounds and is not uniform across rings
• Sizes range from centimeters to meters
• Rings structured into ringlets and gaps
The Roche Limit:
• Any object will break apart by tidal forces if it gets
too close to the planet
• Distance of breakup is called the Roche limit
and is 2.44 planetary radii
• For rings to persist they must be replenished
• Existence of side-by-side ringlets of different
compositions indicates rings supplied by varied
comets and asteroids
http://saturn.jpl.nasa.gov/
http://saturn.jpl.nasa.gov/
• Channels cut by running liquid
• Evidence of thunderstorms
• Atmospheric pressure 50% > than
earth’s
• Ethane (C2H6) lakes confirmed
• Hydrocarbon dunes
http://saturn.jpl.nasa.gov/
http://saturn.jpl.nasa.gov/
Reflection of Sunlight off Titan Lake
http://saturn.jpl.nasa.gov/
http://saturn.jpl.nasa.gov/
http://saturn.jpl.nasa.gov/
• Discovered in 1781 by William
Herschel
• Composed of 83% hydrogen, 15%
helium, 2% methane
• Winds up to 360 mph
• Mean cloud temperature = -193°C
• Distance from Sun: 19 A.U.
• Period = 84 years
• Blue color due to methane in
atmosphere
• Mass = 14.5x Earth’s mass
• At least 22 moons
• Diameter = 4x earth’s
• Ring system
• Axial tilt = 98°; Uranus is on its
side!
• Magnetic Poles tilted > 60° with
respect to its axis
• Discovered in 1846 by Johann
Galle
• A day on Neptune is 16 hours and
6.7 minutes
• Diameter = 4x earth’s
• winds blow up to 2,000 kph
(1,200 mph) an hour
• Distance from Sun: 30 A.U.
• Period = 164 years
• Blue color (methane)
• Mass = 17x Earth’s mass
• Ring arcs
• Neptune has cloud belts
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One of its six moons is Triton
Triton’s orbit is retrograde
Triton has an atmosphere
At least one geyser caught in
eruption by the passing Voyager II