Transcript 22.Jupiter-moons[1]

Moons of Jupiter – total of 63 confirmed!
a.
b.
Inner moons closer to Jupiter than Io
Amalthea
Jupiter’s Galilean Satellites – Worlds of their
own!
Io
Europa
To Jupiter
Ganymede
Callisto
Sizes of some of the Galilean satellites of Jupiter
Jupiter’s moon Io,
volcanologically the
most active body in
our Solar System.
1.) Color - sulfur!
2.) Albedo - 63 %
3.) No impact craters - fresh
surface
4.) Recent lava flows
5.) Numerous calderas
6.) Numerous active
volcanoes, spewing out sulfur
and silicate lava
Io
Voyager’s discovery of active volcanic plumes on Io
Views of Pele
Plume:
1,300 km wide
600 km high
Plumes seen on limb and as shadows on surface
Limb view
Plume shadow
Long lava flows at Ra Patera > 100 km long
Lava flows on Io
Examples of lava lakes at Kilauea, 1988
Where does the heat come from on Io?
Tidal heating from Jupiter, Europa and Ganymede
Interior of Io; density = 3.55 gm/cc
Iron-rich core
Thin silicate crust
Molten interior
Jupiter’s Galilean Satellites – Worlds of their
own!
Io
Europa
To Jupiter
Ganymede
Callisto
Europa: 3,138 km diameter; density 3.04 gm/cc
Ideas for a frozen interior for Europa
Ideas for a liquid interior for Europa
How do we get heat into the interior of Europa?
• Tidal heating.
Europa is tugged
towards Jupiter, but is
also pulled away
from Jupiter by Io,
Ganymede and
Callisto.
• Without tidal heating,
Europa would look
like Callisto.
Colored bands – fractures in ice crust
Multiple periods of
fracturing
Topography of fractures on Europa
Some craters are found on Europa – but very young!
“Icebergs” on Europa suggest thin (5 – 20 km) crust
If there is volcanism on Europa, ice may be thin, so…..
Model of hot interior
of Europa
Black smokers
on Earth
Tube worms on Earth’s
ocean floor hint that
similar life could evolve
on Europa without
sunlight
Ganymede: 5,262 km diameter; density 1.94 gm/cc (Mercury
diameter = 4,880 km)
Light and dark terrain on Ganymede – long geologic history
Grooves on Ganymede – signs of surface
movement similar to plate tectonics on Earth?
Grooved Terrain on Ganymede
Signs of comet impacts? Chains of craters with ejecta
Magnetometer data give clue to interior of Ganymede
Iron core
Ice crust
Liquid water
Silicate lower
mantle
Callisto: Diameter 4,800 km, density 1.86 gm/cc
Thousands of craters at all scales on Callisto
Valhalla basin - ~600 km in diameter
Details of a “ring” of Valhalla Basin
Magnetometer data give clue to interior of Callisto
Solid rock-ice
Ice-rich outer layer
Relative ages of the surfaces of the Galilean Satellites:
From left to right, from young to old.