Lecture Eight Flashcards
Describe the characteristics for Jupiter.
Fifth planet from the Sun.
317.828 * the Earth’s mass.
10.9733 * Earth’s radius.
Average density = 0.241 * Earth.
Massive atmosphere of hydrogen and helium, and traces of methane.
Temperature at the cloud tops = 125K and increases as you go towards the core.
Not sure whether core is solid, or if whole planet is gaseous.
What is the great red spot on Jupiter?
A storm that has lasted at leave 180 years, but is shrinking.
Wind speeds of up to 400km/h, central rotation speed is increasing over time.
Other storms appear and fade, but so far it is still there.
What are Jupiter’s moons?
Has 67 moons.
Four of them are large (Io, Europa, Ganymede, Calisto) varying in composition from rocky to icy.
Others appear to be captured asteroids.
Describe the characteristics of Io, one of Jupiter’s moons.
Inner most moon,
Size and density around the same as our moon.
Radius 1821.6 km.
Trace atmosphere of SO2 which is spat out of its volcanoes, but it doesn’t have enough energy to hold the gas in for long.
Metallic Ni and Fe core.
Silicate (partially molten potentially) mantle and crust
No significant differentiation between mantle and crust, although crust has more sulphur.
Most volcanically active body in the solar system.
500km^3 per year for lava released (compared to 15km ^3 per year on Earth) (that is 30* more volcanically active than Earth).
Hottest lava observed in the solar system.
Describe the characteristics of Europa, one of Jupiter’s moons.
Has a complex icy surface.
Has the major terrain types of bands, ridges, plains and chaos terrain.
Formed by what can best be called ‘Ice Tectonics.’
Complex terrain of icebergs and refrozen surface.
This terrain can only have formed if there is a liquid like substance underneath the upper most crust.
There may be a subsurface ocean under Europa’s icy surface.
There are geysers at the pole of Europa which is evidence of a liquid ocean under the ice.
Describe the characteristics of Ganymede, one of Jupiter’s moons.
Bands of light and dark material across the planets surface.
Heavily cratered surface.
Internally generated magnetic field, so may have differentiated core.
There may be a subsurface ocean, or ice.
There is significant evidence of surface movement in the past.
No evidence of current movement.
geologically inactive planet.
Describe the characteristics of Callisto, one of Jupiter’s moons.
Frozen surface.
Potentially has a subsurface salty ocean indicated by the presence of electrical currents.
What are the characteristics of Saturn?
Sixth planet from the Sun.
Massive atmosphere of hydrogen, helium and trace amounts of methane gas.
Rings of rock and ice are held in place by the gravitational forces of captured asteroid moons.
Temperature at 1 atmosphere level (just within clouds) = 134 K.
Describe the characteristics of Titan, one of Saturn’s moons.
Nitrogen and methane atmosphere.
Complex carbon molecules make smog we can’t see thought, so we need a radar to see the surface.
Oceans, lakes and rivers and rain of liquid methane are present.
Describe the characteristics of Enceladus, one of Saturn’s moons.
Resurfacing of about 60-70% of the planet.
Not enough known yet to determine the source.
Geysers of water ice erupt from the south pole ridges.
Descrive the characteristics of Lapetus, one of Saturn’s moons.
Has a mark on it made of the material being spat from Enceladus.
Describe the characteristics of Uranus.
Seventh planet from the Sun.
Massive atmosphere of hydrogen, helium and methane.
Mean temperature of 59K (really cold :().
Rotates backwards on axis at massive tilt (almost equilateral).
Faint ring system and 27 moons.
Describe the characteristics of Miranda, one of Uranus’ moons.
Radium = 236km
Composition = 50% rocky material, 50% water ice.
Striated and ridged surface, with massive troughs and scraps.
The fact that Uranus was hit by something bit enough to change its spin direction and the position of its rotational axis means that the ejecta from the impact, or just the change in gravitational pull resulting from the rotational shift could have caused Miranda to shatter.
Origin of surface may be related to origin of horizontal axis of rotation.
Two theories of the origin of it’s weirdo surface:
1) Miranda has been completely shattered and reassembled several times in history, each time burying some parts of the original surface and exposing some of the previous interior.
2) Rifting and undercutting by upwelling and convection of partially molten ice. t make much geological sense apparently.
Comare Mimas (moon of Saturn) with Miranda (moon of Uranus).
There is a massive crater which is just below the size that would have shattered Mimas.
A similar sized impact would have broken Miranda, and then ridges and terrain could result from the peaces slamming back to ether under their gravitational attraction.
Describe the characteristics of Neptune.
Eighth planet from the Sun.
Massive atmosphere of hydrogen, helium and methane.
Mean temperature = 48K.
Faint ring system and 14 known moons.
Cloud colours change with proximity to Sun - reasons unknown.
