Other Moons, Rings, and Pluto

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Other Moons, Rings, and Pluto

• Group 19
• Lisa Cowan
• Diane Khuu
• Sarah Dane Lara
• Noel Salunga

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OVERVIEW -      Titan-       Triton-      
The Medium-Sized Jovian Moons-       Saturns
Rings-       The Roche Limit-       The Rings
of Jupiter, Uranus, Neptune-       Planetary
Ring Formation- Pluto and Charon
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THE LARGE MOONS OF SATURN AND NEPTUNE  
TITAN -        Largest of Saturns
moons -        Comparison to Ganymede and
Callisto  
 
Titans Atmosphere -        Gives red
coloration -        Similar to smog on
Earth Envelopes the moon
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Why does Titan have an atmosphere when Ganymede
and Callisto do not? -        -Titan has a
surface temperature of 94K -        -Gasses may
have become trapped in the surface ice the moon
formed -Internal radioactivity
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TRITON -        Neptunes largest moon smallest
of the six large moons in the solar
system. -        Icy surface -        Surface
temperature of 37K -        Extremely thin
atmosphere   Tritons surface -        Solid
frozen surface -        Tritons polar ice
caps -        Lack of catering -       
Cantaloupe like terrain -        Frozen lakes
of water ice -        Nitrogen geysers
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Tritons orbit is retrograde -Captured from the
Kuiper Belt? Tritons future - Triton spirals
toward Neptune
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Medium-Sized Jovian Moons   There are 12
medium-sized satellites of the Solar System 6
belong to Saturn 5 belong to Uranus 1 belongs
to Neptune
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Facts -Based on their densities scientists
believe that all are composed of largely composed
of rock and water ice.   -They move nearly in
circular path and tidally locked by their parent
planet's gravity into sychronous rotation   -Most
of these moons show no evidence of significant
geological activity   -All Moons show heavy
cratering, indicating the cluttered and violent
planetary environment that existed just after the
outer planets formed, as the remaining planets
were created by larger bodies or ejected from the
vicinity of the jovian planets to form an Oort
Cloud
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The Roche Limit -the critical distance where the
moon is close enough to a planet to be torn apart
by tidal force -the pieces of the destroyed moon
then orbit the planet in rings -the Roche Limit
only applies to moons that are massive enough to
have strong gravity. Tiny objects (spacecraft)
are not torn apart.  
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The Fine Structure of Saturns Rings -the
particles in rings actually move in smaller
ringlets within the orbit -gaps are created by
large particles called moonlets which sweep up
material and leave a path as they move -Cassini
Division is the biggest gap in Saturns rings,
created by Saturns innermost moon, which pulls
particles, making them collide and move into
different orbits -F ring appears braided, because
shepherd satellites pull straying particles back
in -D ring is closest to Saturn, it is dark,
faint and made of few particles -E ring is far
outside the main ring structure surrounding
Saturn and is thought to be the result of
volcanic action on the moon, Enceladus.
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The Rings of Jupiter, Uranus and
Neptune   -Jupiter has one faint ring around its
equator, inside the orbit of its closest
moon.   -Uranus has 11 rings which are dark,
narrow and widely spaced. -were only detected
by stellar occultation -the rings need shepherd
satellites to keep them in place   -Neptune has
four dark rings, one is wide and the other three
are narrow -outer ring is clumped in places,
caused by shepherd satellites -only clumped
portions thick enough to see from Earth
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Planetary Ring Formation TheoriesThe rings of
the jovian planets are less than 50 million years
old1)     constantly renewed by chips of moon
that are broken off by meteoritic impact2)    
are the result of a recent catastrophe a.     
a moon is pulled apart by tidal forces or b.
a moon is brought into collision with another
large satellite
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Example Possible Formation of Saturns
Rings      Saturns rings, amassed, could
create a satellite with diameter of 250 km   -If
within Saturns Roche Limit, the satellite would
tear apart and form the current rings Saturn has
today   -If near the Roche Limit, the satellite
might have collided with another satellite
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Neptunes Rings   -Moon Triton will be torn apart
by Neptunes gravitational field within 100
million years -It will dominate Saturns fading
one   Discovery of Pluto   -Pluto was discovered
in 1930 when it was suspected that an unknown
planet was affecting Uranuss orbit.     -Plutos
discovery was lucky now scientists know that
its mass is way too small to have had an affect
on Uranuss orbit.
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Plutos moon Charon -Studies of its orbit
helped determine its and Plutos masses and
radii. -It has many moonlike qualities. -Greates
t satellite to planet ratio in the solar system.