Jupiter

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					Jupiter
    Vital Statistics

•   R = 71,492 km                 • 11.21 RÅ
•   M = 1.90 x 1027 kg            • 317.8 MÅ
•   Rorbit = 778.4 x 106 km       • 5.2 A.U.
•   T = 124° K
•   Eccentricity = 0.048
•   axial tilt = 3.08°
•   “day” = 9.84 hours
•   “year” = 11.86 years
•   orbital inclination = 1.31°
A bit of background
• Known since prehistoric times
• One of Galileo’s 4 big discoveries
• 63(?) moons to date
• moons are named for figures in the life of Zeus
  (mostly his lovers)
• faint rings
• gradually slowing down
• Io, Europa, and Ganymede are locked in a 1:2:4
  orbital resonance (in a few million years, Callisto
  will be locked as well, with an orbit 8 times that
  of Io)
Claims to fame
• Largest planet in the solar system
  – so large that even causes a wobble in the sun’s
    motion that would be detectable from other
    stars
• Boasts the most geologically active moon
  in solar system
• Great Red Spot
• visible bands (even visible from Earth with
  backyard telescopes)
The Great Red Spot
• Origin is unknown
• A storm about 2 times Earth’s diameter
• Has been raging for at least 300 years (Discovered
  by either Cassini or Robert Hooke in the mid-17th
  century)
• gas flow around the spot is counterclockwise, with a
  period of about 6 days at speeds up to 2770 mph
• center is tranquil (like the eye of a hurricane)
• gas north of the spot flows westward, whereas gas
  south of the spot flows east
Series of pictures
taken by HST between
1992 and 1999
Movie interlude

•   http://www.nineplanets.org/pxjup.html
•   look at Jupiter “Day”
•   Rotating Jupiter
•   Red spot
Visits

• Pioneer 10 in 1973 (1st visit)
• Pioneer 11
• Voyager 1
• Voyager 2
• Ulysses (was really just using Jupiter for a
  gravity boost)
• Galileo
Pioneers

• 10 was 1st to Jupiter - just a flyby
• Pioneers were designed to test the ability of
  spacecraft to survive passage through the
  asteroid belt and Jupiter’s magnetosphere
• 11’s power supply is dead, but 10 is still
  functioning
• will be 1st craft to reach interstellar space
  – bear plaques trying to convince aliens we’re
    intelligent
Voyagers
    Voyagers
• Voyager 1 launched Sept 5, 1977 and flew past
  Jupiter March 5, 1979
• Voyager 2 launched Aug. 20, 1977 (before V1) and
  flew by Jupiter August 7, 1979
• Most of what we know about the gas giants comes
  from Voyagers 1 and 2
• Discovered
  – that Jupiter has complicated atmospheric dynamics,
    lightning, and aurorae
  – 3 new satellites
  – ring system
  – Io has active sulfurous volcanoes
Galileo
Galileo

• Launched Oct 18, 1989, arrived 1995
• 1 slingshot around Venus, 2 around Earth
• Tested instruments while at Venus
• High-gain antenna didn’t open as planned,
  so they reprogrammed the computer to use
  the smaller antenna (and we got most of the
  data it sent)
• Discovered a “moon” orbiting the asteroid
  Ida
Galileo

• In 1994, could see Shoemaker-Levy 9 crash into
  Jupiter
• Spacecraft (orbiter) and probe
• Probe descended 95 miles, collected 58 minutes of
  data on weather
• appeared that atmosphere is dryer than we thought
  (but later we realized the probe had entered a hot
  spot)
• near end of 58 minutes, probe measured winds of
  450 mph (melted and vaporized shortly after that)
   Structure and Atmosphere

• Atmosphere: 86.1% H2, 13.8% He
  – also: ammonia, methane, water vapor
• Presence of lots of H2 and He is a result of strong
  gravity
• Bright “zones” (other gas planets have them, but
  they’re most pronounced on Jupiter) and dark
  “belts”
Atmosphere




• Upwelling in zones, sinking in belts
• high pressure in zones (low in belts)
     Atmosphere - Zonal flow

• Underlying the bands is a
  stable pattern of eastward
  and westward wind flow,
  known as “zonal flow”
• note: belts and zones are
  related to zonal flow
  pattern
• Note - equatorial regions of atmosphere rotate faster than the
  planet - average flow speed of about 85 mph (similar to
  Earth’s jet stream)
Atmosphere - structure

• None of the gases listed
  earlier can account for
  coloration
• We believe cloud colors
  are the result of complex
  chemical processes
• A model based on available
  data and some math
• Galileo probe made it to the
  bottom of this diagram
    Internal structure

• This diagram is based on
  Voyager data and
  theoretical modeling
Auroras
    Rings




Galileo image - clearly shows radial structure that had only been hinted
in Voyager images
Moons

• Ganymede, Callisto, Europa, Io
• Metis, Adrastea, Amalthea, Thebe
• Leda, Himalia, Lysithea, Elara, Ananke,
  Carme, Pasiphae, and Sinope
• At least 47 others, some of which have been
  named
    Ganymede

• Largest moon in
  Solar System



• Weird grooves




                    27
Callisto

• Oldest, most cratered surface of any body in
  Solar System
• uniform interior of ice and rock mixture




                                        29
30
    Io
• Very close
  to Jupiter
• Active
  volcanos




               31
     Europa

• Only other body in
  Solar System with
  liquid water

• VERY smooth




                       32
Europa interior

				
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posted:5/19/2013
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