Transcript Jupiter - Moodle

Outer Planets
Gas giants -Jovian Planets:
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Jupiter
Saturn
Uranus
Neptune
The gas planets do not have solid surfaces,
their gaseous material simply gets denser
with depth
What we see when looking at these planets is
the tops of clouds high in their atmospheres.
Jupiter
orbit: (5.20 AU) from Sun
• Jupiter (a.k.a. Jove;
Greek Zeus) was the
King of the Gods, the
ruler of Olympus and
the patron of the
Roman state
• Zeus was the son of
Cronus (Saturn)
Jupiter
• fourth brightest object in the sky
– (after the Sun, the Moon and Venus; at some
times Mars is also brighter).
• It has been known since prehistoric times
In 1610, Galileo discovered
Jupiter's four large moons
This was the first discovery of a
center of motion not apparently
centered on the Earth
now known as the Galilean moons
Supported Copernicus's heliocentric
theory of the motions of the
planets
Galileo's outspoken support of the
Copernican theory got him in
trouble with the Inquisition
Heliocentric—sun-centered
Four Moons of Jupiter
• Io--volcanic
• Europa—liquid
water???
• Ganymede
• Callisto
Io—the volcanic “pizza” moon
• Io very volcanic
because of the
gravitational pull of
Jupiter on its
surface
• Its surface moves in
and out about 100
meters
Europa
• Greatest possibility of
life
• Possibility of liquid
water beneath the icy
surface
• This picture shows
cracks in the ice
•
Gannymede and Callisto are both highly cratered
• Jupiter is about 90% hydrogen and
10% helium (by numbers of atoms,
75/25% by mass) with traces of methane, water,
ammonia and "rock"
• Very close to the composition of the
primordial Solar Nebula from which the entire
solar system was formed
• Saturn has a similar composition, but Uranus
and Neptune have much less hydrogen and helium
Saturn
9.54 AU from Sun
Galileo was the first to
observe it with a telescope
in 1610
In Roman mythology, Saturn
is the god of agriculture
Saturn is the root of the
English word "Saturday"
Earth passes through the
plane of Saturn's rings
every few years as Saturn
moves in its orbit.
Saturn is
the least dense of the planets
• specific gravity (0.7) is less than that of
water
–It could Float!!!
• Saturn's interior is hot
• Saturn radiates more energy into
space than it receives from the Sun.
Uranus
19.218 AU from Sun
• Careful pronunciation may be necessary to
avoid embarrassment; say "YOOR a nus",
not "your anus" or "urine us".
97º tilt
• Most of the planets
spin on an axis nearly
perpendicular to the
plane of the ecliptic
but Uranus' axis is
almost parallel to the
ecliptic.
Uranus' blue color is
the result of
absorption of red light
by methane in the
upper atmosphere
How’d it get that name?
Uranus is the ancient Greek deity of the
Heavens, the earliest supreme god.
The name "Uranus" was first proposed by
Bode in conformity with the other planetary
names from classical mythology but didn't
come into common use until 1850
Composition of Uranus
• composed primarily of rock and various ices
• only about 15% hydrogen and a little helium in
contrast to Jupiter and Saturn which are mostly hydrogen
• Uranus (and Neptune) similar to the cores of
Jupiter and Saturn
– minus the massive liquid metallic hydrogen envelope
• Uranus does not have a rocky core like Jupiter and
Saturn but rather that its material is more or less
uniformly distributed
Uranus' atmosphere is about 83% hydrogen,
15% helium and 2% methane
Uranus is sometimes just barely visible with
the unaided eye on a very clear night; it is
fairly easy to spot with binoculars (if you
know exactly where to look)
Neptune
0.06 AU from Sun
• In Roman mythology
Neptune
(Greek: Poseidon) was the
god of the Sea
Methane gas atmosphere
• Neptune's winds are the
fastest in the solar system,
reaching 2000 km/hour
Eccentric orbit
Because Pluto's orbit
is so eccentric, it
sometimes crosses
the orbit of
Neptune making
Neptune the most
distant planet from
the Sun for a few
years
Eccentricity
• How squished
the elliptical
orbit is
Neptune’s Discovery
• After the discovery of Uranus, it was
noticed that its orbit was not as it should be
in accordance with Newton's laws. It was
therefore predicted that another more distant
planet must be perturbing its orbit.
• Perturbation--Variation in an orbit due to the
influence of external bodies
– Retrieved from "http://en.wiktionary.org/wiki/perturbation"
Pluto
and
Charon
Pluto
• Pluto is the farthest planet from the
Sun (usually) by far the smallest.
Pluto
• So. . . a day is longer than a
year
Pluto and Charon
• Pluto’s moon
• Discovered July
1978
• Covered with water
ice instead of
nitrogen ice
• 1/7 the size of Pluto
Important
Terms
• Eccentricity—how squished the elliptical
orbit is (how oval the oval is)
• Period—one revolution around the sun
• Heliocentric—the sun is the center of the
solar system
• Geocentric—the Earth is the center of the
solar system