The Outer Planets

							The Outer Planets
2009
The Outer Planets
   The outer
    planets are
    made of gases.
   The outer
    planets are
    very large.
      Gas Giants
   Separated from the 1st
    zone by the asteroid belt,
    the 2nd Zone contains the
    gas giants.
   Made of the lightweight
    elements Hydrogen,
    Helium, Carbon, Oxygen,
    and Nitrogen.
   All are much larger than
    the Earth, with 15-300
    times the mass, and 4-11
    times the diameter.
   Not believed to have solid
    surfaces.
   Have rings and many
    satellites.
      Gas Giants Atmospheres
   Since they have so much
    mass, their strong gravity can
    keep even light gases from
    escaping.
   Atmosphere tends to resemble
    the sun (75% H, 24% He, 1%
    other gases).
   No well defined surface.
    Gases just get denser and
    denser as you go deeper.
    Becomes liquid metallic
    hydrogen, which has
    properties of liquids and
    metals. Exist only under high
    pressure. Causes Jupiter's
    magnetic field.
    Gas Giants Cores
   Gas giants are
    believed to have
    solid cores made
    of rock,, ice,
    frozen carbon
    dioxide, and
    other
    compounds.
   Cores would be
    several times
    the size of the
    Earth.
Jupiter, King of the
Roman Gods
   Named for Jove,
    the King of the
    Roman Gods.
   Roman name for
    the Greek god
    Zeus.
   Often the term
    Jovian is used to
    describe things
    pertaining to
    Jupiter. Example:
    the Jovian moons.
      Jupiter
   Believed to be a failed
    star, lacking the mass
    to become a small star.
   Most massive planet in
    solar system.
   Has over 60 satellites.
   Density is 1.33g/cm3.
   Rotates every 10
    hours.
   Takes 12 years to orbit
    the sun.
   Gravity almost 2.5
    times that of the Earth.
Jupiter Atmosphere

      Mainly hydrogen
       with some helium.
      Very active weather
       systems.
      Forms colorful
       bands and swirls.
      Has hurricanes that
       last for 100’s of
       years.
    Great Red Spot
   The red spot is a
    huge storm that has
    been continuously
    going on Jupiter for
    over 400
    years. Winds inside
    this storm reach
    speeds of about 270
    mph. With a
    diameter of 15,400
    miles, this storm is
    almost twice the size
    of the entire Earth.
Jupiter's Moons
   Galileo discovered the
    four largest. Io,
    Ganymede, and
    Callisto are larger than
    our own moon.
   Europa has a icy crust
    and is believed to
    have liquid water
    oceans below the
    frozen surface.
   Io has many active         Ganymede is the largest
                               moon in our solar system.
    volcanoes.
Missions to
Jupiter
   http://www.window
    s.ucar.edu/tour/link
    =/jupiter/space_mis
    sions.html

   http://www.solarvie
    ws.com/eng/craft2.
    htm#jupiter
Shoemaker Levy 9
   In July 1994, Comet
    Shoemaker-Levy 9 collided
    with Jupiter with spectacular
    results (left). The effects
    were clearly visible even
    with amateur telescopes.
    The debris from the collision
    was visible for nearly a year
    afterward with HST.
   Captured by Jupiter's strong
    gravity, the comet was torn
    into over 20 fragments that
    struck Jupiter, each with a
    force of millions of megatons
    of energy.
   This has renewed NASA’s
    interest in tracking objects
    that might get close to Earth
    one day.
Jupiter
   Diameter: 11 earth's
   Distance: 5 Au
   Atmosphere: mainly hydrogen with some
    helium
   Features: active weather with storms that
    last for 100s of years (GRS)
   Over 60 moons, most in our solar system
   Life: none
     Saturn the God
   Saturn was the Roman God
    of the Harvest and of Time.
   Father of Jupiter, Neptune,
    and Pluto.
   The Roman name for the
    Greek god Cronos.
   Saturnalia was the mid-
    winter festival in Saturn's
    honor. It lasted seven
    days, and there was much
    merrymaking. Public
    business was suspended
    and schools were closed.
    Parents gave presents to
    their children.
      Saturn Facts
   2nd largest planet in solar
    system.
   A “day” on Saturn is a
    little over 10 hours long!
   It takes 29 years to orbit
    the sun.
   Almost 10 times larger
    than Earth.
   Most visible rings of any
    planet.
   Density is 0.69 g/cm3.
   If a large enough ocean
    could be found, Saturn
    would float in it!
Saturn’s
Atmosphere
    Similar to Jupiter’s,
     mostly hydrogen with
     some helium.
    Storms not as large or
     as long lived as
     Jupiter's.
    Clouds are thicker,
     blocking views to
     lower layers. Explains
     the lack of banding
     compared to Jupiter.
    Saturn’s
    Rings
   Very spectacular. Not
    at all solid.
   Made of tiny bits of
    ice, dust, and rock. A
    few are up to a
    kilometer across.
   Only about a kilometer
    thick.
   The Cassini space
    probe actually passed
    through the outer ring
    as it slowed down to
    enter orbit.
Saturn’s Moons
   Has over 40 moons, 15 or so that are large
    enough to be called major moons.
     Titan
   Titan has an
    atmosphere made of
    about 99% nitrogen
    and 1% methane.
   Has a pressure of 1.6
    atmospheres.
   Completely covered
    by thick clouds that
    are similar to smog
    on Earth.
   The second largest
    moon, it is larger
    than Pluto and
    Mercury.
Cassini-
Huygens
   The Huygens probe
    actually parachuted
    into the atmosphere of
    Titan on 14 January
    2005.
   It took pictures and
    collected data all the
    way to the surface. It
    survived the landing
    and sent back pictures
    of the surface it landed
    on.
Saturn
   Diameter: 9 times larger than Earth
   Distance: 10 Au
   Atmosphere: 96% Hydrogen 4% Helium
   Features: Has short storms, rings orbit it
    that are made up of bits of ice, dust, and
    rock
   Life:no life although Titan has possibilities.
Uranus the God

   URANUS: Great
    primeval God of the
    Sky. Born of GAIA,
    the Earth, he
    covered the world
    in the form of a
    vast bronze dome
    and ruled over
    everything.
Uranus Facts
   Diameter is like 4
    Earth’s.
   Mass is 14.5
    Earth’s.
   Takes 84 years to
    revolve around the
    sun.
   Day is a little over
    17 hours long.
   Has more than 20
    moons.
Uranus Axis
   Uranus is considered
    unusual because the
    planet is tipped on its
    side. The poles actually
    point towards the Sun.
   its magnetic field is
    tilted 60 degrees from
    the axis of rotation.
   It is believed that
    Uranus was struck by a
    large object that
    knocked Uranus on its
    side.
Uranus Seasons
Uranus Atmosphere
   First, there is
    absolutely no detail
    in the cloud cover.
    Only when pushed
    to the maximum
    level of color
    enhancement and
    contrast on
    computers do
    scientists start to
    see small swirls in
    the atmosphere.
      Uranus Moons
   5 large and many small
    moons.
   Titania is the biggest
    moon of Uranus. It is
    about half the size of
    our moon. Titania is
    covered by many small
    craters, a few huge
    impact basins ice cliffs,
    and fault lines.
   Ariel: The brightest
    moon of Uranus.
    Youngest surface of
    Uranus' moons, the
    least cratered. Has long
    valleys and canyons.
Uranus
   Diameter:4 Earth’s
   Distance:19 AU
   Atmosphere:82% Hydrogen 15% Helium
   Features: extreme seasons because axis is
    tipped on its side and no detail in cloud
    cover
   Life: no life, too cold, atmosphere and
    surface would not allow life as we know it.
Neptune the God

   Neptune is the
    Roman god of the
    sea.
   The Romans
    modeled him after
    the Greek god
    Poseidon.

     Neptune its
    Neptune revolves on
    axis every 18 hours.
   It takes 165 years to
    revolve around the sun
    once.
   Has the mass of 17
    Earths.
   Has 13 moons.
   Diameter is almost 4
    times larger than Earths.
   Blue-green color is from
    the methane in the
    atmosphere.
   At times it is the furthest
    planet from the sun.
Neptune Atmosphere

   80% hydrogen,
    19% helium, and
    1.5% methane.
   Has icy clouds and
    enormous storms.
   Has the fastest
    winds in our solar
    system.

        Triton is
    Neptune's largest moon
    named Triton. Triton is much
    larger than any of the planet's
    other moons.
    Triton is a very cold place, so
    the moon is covered with ice.
    Even though Triton is cold
    there is a lot going on there. It
    has geysers like the ones at
    Yellowstone Park on Earth.
    The geysers shoot ice 8 km (5
    miles) high into Triton's thin
    atmosphere! There may be
    water under the ice at Triton.
    It is even possible that there
    might be life in that water. The
    interior of Triton is probably
    geologically active.
Neptune’s Rings
   Neptune's rings are
    much darker than
    Saturn's bright
    rings.
   Saturn's rings are
    made of ice, which
    reflects lots of light.
    Neptune's rings are
    probably made of
    rocks and dust.
   Rocks and dust
    don't reflect as
    much light.
Neptune
   Diameter: 4 times the size of Earth
   Distance: 30 Au
   Atmosphere: 80% Hydrogen 19% Helium
    1.5% Methane
   Features: At times it is the furthest planet
    from the sun. Icy clouds and enormous
    storms, one called the Great Dark Spot.
   Life:possible life on one of its moons
    called Triton
    Dwarf Planets
   Planets must:
   Be in orbit around
    Sun.
   Have enough mass
    so gravity makes
    them round.
   Have cleared their
    orbit of similar
    objects.
   Today we know of
    five: Pluto, Ceres,
    Eris, Haumea, and
    Makemake.
   Except for Ceres, all
    are in the Kuiper
    Belt.
Pluto the God

   Pluto was the
    Roman name for
    Hades, the Greek
    god of the
    Underworld.
      Pluto Facts
   Usually the furthest
    planet from the sun.
   2/3rds the size of our
    moon.
   Has one moon, Charon.
   So cold that oxygen and
    nitrogen in its
    atmosphere is frozen
    solid.
   Only planet not visited by
    a spacecraft.
   Pluto takes 248 years to
    make one orbit around
    the sun!
       Pluto’s Atmosphere
   When Pluto comes close enough
    to the sun, the surface of solid
    Nitrogen sublimates to produce
    a substantial atmosphere with
    winds and clouds.
   Because the planet is so small,
    however, it does not have
    enough gravity to bind an
    atmosphere for very long. Thus
    Pluto's atmosphere is being
    rapidly produced and rapidly
    lost at the same time.
   This means that the atmosphere
    is not in equilibrium.
   Similar to comets when they get
    close to the Sun.
          Pluto’s Orbit
   Pluto has the most eccentric orbit of
    all the planets in the solar system.
    Its orbit takes it to 49.5 AU at its
    farthest point from the Sun. And its
    orbit takes it as close as 29 AU to
    the Sun.
   That means that Pluto's orbit draws
    within the orbit of Neptune, as can
    be seen in this drawing, making
    Pluto the 8th planet rather than the
    9th planet for roughly 20 years at a
    time.
   Pluto was the 8th planet from
    January 1979 to February 1999.
    Neptune is now the 8th planet for
    over 200 years!
       Charon
   Named for the boatman
    who ferried the dead into
    the Underworld.
   Surface seems to be
    covered with water-ice
    instead of Pluto’s
    nitrogen-ice.
   Largest moon compared
    with its planet.
   Two recently discovered
    tiny moons, called Nix
    and Hydra, orbit twice as
    far from Pluto as Charon.
Pluto Debate
   Is Pluto really a planet?
   Pluto is small that many
    scientists now consider
    Pluto just another Kuiper
    Belt object, which are
    small icy worlds in the
    third zone.
   Many have been
    discovered so far, and it
    is believed there are
    thousands more out
    there.
   In July 2005 a KBO larger
    than Pluto was
    discovered. Named Eris,
    after the Greek/Roman
    goddess of discord.
     New Horizons
   Mission to Pluto:
    launched January 19,
    2006
   As of April 2011, it
    has covered 20 AU,
    just passing the orbit
    of Uranus. It is
    halfway there!
   It will have a 21 day
    encounter with
    Pluto/Charon in July,
    2015.
   Hopefully it will then
    head off to encounter
    other Kuiper Belt
    Objects.
Pluto
   Diameter: 0.2 Earth
   Distance: 39 Au
   Now considered a dwarf planet.
   Atmosphere: Oxygen and nitrogen atmosphere,
    almost always frozen. Might have a brief
    atmosphere when the frozen gases sublimate as
    Pluto makes its closest approach to the Sun.
   Features: most eccentric orbit, some scientists
    think it might also have retrograde rotation like
    Venus.
   Life:too cold. no!