Saturn
Happy Halloween – who says the boys and girls
at NASA have no sense of humor
Relative Size of Planets
Planetary Fact Sheet – Planet
Comparisons
• http://nssdc.gsfc.nasa.gov/planetary/factshee
t/index.html
Size comparison, rocky planets and
moons.
True Saturn – from Cassini Spacecraft
Saturn: just the basic facts
• Saturn, like Jupiter, is made mostly of
hydrogen and helium.
• Winds in the upper atmosphere reach 500
meters per second in the equatorial region.
• In contrast, the strongest hurricane-force winds
on Earth top out at about 110 meters (360 feet)
per second.
Saturn: just the basic facts
• These super-fast winds, combined with heat
rising from within the planet's interior, cause the
yellow and gold bands visible in the atmosphere.
• Saturn’s day length is 10.7 hours.
• Saturn’s year is 29.7 Earth years.
• It has an escape velocity of over 80,000 miles per
hour (Earth’s is 25,000 miles/hour).
Saturn: just the basic facts
• 568,319,000,000,000,000,000,000,000 kg
– In Sci. Notation: 5.6832 x 1026 kg
– Earth’s mass: 5.972 X 1024 kg.
• Its volume is 755 times greater than that of Earth.
• Distance from the sun: 1.43 billion km, or 9.58
AU.
• Surface Gravity – if you weigh 100 lbs on Earth,
you would weigh 107 lbs on Saturn.
Saturn’s Rings
• In the early 1980s, Voyager 1 & 2 revealed
that Saturn's rings are made mostly of water
ice – from fine grains to chunks as large as a
house.
• Also, they imaged "braided" rings, ringlets,
and "spokes.“
– dark features in the rings that form and initially
circle the planet at different rates from that of the
surrounding ring material.
The Rings
• Saturn and several of its moons hold the
whole jumble together in a powerful
gravitational grip.
• Moons like Pan, Atlas and Pandora are called
shepherd moons - they herd particles into
Saturn's rings.
• The moons also create gaps and twisting wave
patterns.
Cassini Composite of Saturn’s Rings
The Rings
• Saturn's ring system extends hundreds of
thousands of kilometers from the planet, yet
the vertical height is typically about only 10
meters (30 feet) in the main rings.
This is a JPL
illustration of
Saturn’s Rings
The Rings
• During Saturn's 2009 autumnal equinox, when
sunlight illuminated the rings edge-on, Cassini
spacecraft images showed vertical formations
in some of the rings.
– particles seem to pile up in bumps or ridges more
than 3 kilometers (2 miles) tall.
Why Study Saturn’s Rings?
• Why are Saturn’s rings more than just
beautiful?
• According to a number of things I read, the
rings are kind of like a model of the early solar
system.
• "The small moons embedded in the rings close
into Saturn interact with the rings, [which] is
similar to the interactions that likely occurred
in the early solar system itself.“
Why Study Saturn’s Rings?
• "The moons sweep up and sculpt the rings and
release ring material. They create waves and
establish resonances in the rings. And so
studying the rings is like studying the early
solar system and the formation of the planets.”
• Dr. Amanda Hendrix, a planetary scientist with NASA.
Titan
• Saturn has 53 known moons and Titan is by far
the largest.
• With an equatorial radius of 2,575 km (1,600
miles), Titan is the second largest moon in our
solar system.
– It is larger than Mercury and only Jupiter’s moon
Ganymede is larger (slightly larger).
Titan’s Atmosphere
• The temperature at Titan's surface is about 289 degrees Fahrenheit (-178 degrees
Celsius).
• Titan is of great interest because it has clouds
and a thick atmosphere, which extends farther
out into space than Earth’s.
– Most of its atmosphere is Nitrogen (like Earth’s)
with methane the second most common
substance.
Titan’s Hydrocarbons
• Titan and Earth are the only two objects in our
solar system with large amounts of organic
compounds.
• Titan's organic materials, including deposits of
methane and other hydrocarbons, are as large
as some of the Great Lakes
– Earth’s hydrocarbons have been cycled through
living organisms, Titan’s haven’t (pristine).
Titan’s Smog Problem
• Due to Titan’s gaseous hydrocarbons, it has
smog.
– Sunlight, like here on Earth, breaks hydrocarbon
compounds into pieces that react with each other
and nitrogen to form organic compounds.
– Those include ethane, acetylene, hydrogen
cyanide, cyanoacetylene and other familiar
terrestrial chemicals (that we consider serious air
polluntants).
An Impression of Titan’s Surface from
Hyugen’s Data
http://www.sciencedaily.com/releases/2012/09/120928085222.htm
Possible Life on Titan?
• Recent research has provided fascinating hints
that liquid water may exist deep under Titan's
surface.
• Titan's seafloor may be similar to areas of
Earth's seafloor where hydrothermal vents
exist.
• These passageways into Earth's interior spout
hot, mineral-rich water that fosters an array
of once-unknown forms of life.
Seasons Change on Titan
BBC Cassini-Hyugens Probe
Documentary
• https://www.youtube.com/watch?v=jgRqUGLt
vmM
An unrequited mission
• After Cassini-Hyguens, there was urgency to
launch a follow up mission (to “sail Titan’s
methane seas”).
• https://www.youtube.com/watch?v=pL4LTFB
O10Q