astronomy_04_chapter_12_fall_2017.pptx - Astro 04: The...

Astro 04: The Solar System
Chapter 12: "Rings, Moons & Pluto"
Europa


Callisto is the outermost of
Galilean moons at a distance
of 1.2 million miles.

It is in synchronous
revolution around Jupiter
every 17 days.

The moon has a heavily
cratered surface that has seen
little change over the last 4.4
billion years.
CALLISTO


Callisto froze solid before the
process of differentiation
occurred. It is a geologically
dead world.
CALLISTO

Closeup
of Callisto


Ganymede is the largest moon
in the Solar System.

Parts of its surface are very old
like Callisto but others are
relatively young, perhaps a
billion years old.

Ganymede may have a rocky,
metallic core.

Tidal forces may occasionally
heat the interior and cause water
to erupt and resurface portions
of the moon.
GANYMEDE

Closeup of Ganymede


Europa is predominantly a rocky
world with an ice-covered surface
that is crisscrossed with cracks
and low ridges.

Few craters are evident.

The ice appears to be the frozen
surface of a great water ocean
that has broken up and refrozen
many times.
EUROPA


Tidal forces may generate enough
heat to keep water in the liquid
state not too far beneath the
surface layer of ice.
EUROPA

Closeup of Europa


is a close twin our Moon
with about the same size and
density.

Io has active volcanoes on its
surface. Volcanoes emit hot
rocky lava, sulfur and sulfur
dioxide.

The sulfur and sulfur dioxide
recondense in the cold and
snow down upon Io’s
surface.
IO


Io is constantly resurfacing
itself.
IO

Closeup of Io

Moons of Saturn

19 Moons and Massive Ring System

Titan is most significant satellite and the only moon with a
significant atmosphere

Ring material size of ping-pong, tennis and basketballs.


Saturn’s Titan is about the
size of Jupiter’s Ganymede
and is about half ice and
half rock.

It is the only moon to have
a substantial atmosphere.

The atmospheric surface
pressure is 1.6 times that of
Earth.
Io


Titan’s atmosphere is
composed mostly of
methane. Nitrogen and
hydrocarbon compounds
are also present.

Methane clouds composed
of shroud the surface. The
surface is probably covered
with methane ice and
perhaps methane oceans.
Io

Tethys
Tethys's icy surface is heavily
cratered and contains cracks
caused by faults in the ice. There
is one enormous trench on Tethys
about 65 kilometers wide and
extending from above the center
to the extreme left. It covers three-
fourths of Tethys' circumference.