3 rd brightest object in night sky Alternating light & dark bands Giant Red Spot Galilean moons (Io, Callisto, Ganymede, Europa)

Much fainter than Jupiter; twice the distance from Earth Atmospheric bands less distinct Moons Ring system

Voyager 1 and Voyager 2 Launched in 1977Launched in 1977 Arrived at Jupiter in 1979Arrived at Jupiter in 1979 Both visited SaturnBoth visited Saturn Voyager 2 flew by Uranus and NeptuneVoyager 2 flew by Uranus and Neptune

Galileo Launched in 1989Launched in 1989 Arrived at Jupiter in 1995Arrived at Jupiter in 1995 Orbited Jupiter and its moonsOrbited Jupiter and its moons Was crashed into Jupiter in 2003Was crashed into Jupiter in 2003

Cassini- Huygens Launched in 1997Launched in 1997 Arrived at Saturn in 2004Arrived at Saturn in 2004 Launched the Huygens probe which landed on TitanLaunched the Huygens probe which landed on Titan Continues to orbit Saturn and its moonsContinues to orbit Saturn and its moons

Uranus was discovered in 1781 by William Herschel Originally named after King George III After some study, the predicted and observed position of Uranus were off. This led to the search and discovery of…

Neptune Discovered in 1846 by Johann Galle Neptune is not visible to the naked eye

Due to the composition of the planets (gas) the equator rotates at a different rate than near the poles Jupiter’s equator rotates at 9 h 50 m, higher latitudes are 6 minutes slower Produces an oblate shape

Extra-solar Planets

318x more massive than Earth Diameter is 11x Earth’s 3° axial tilt Distance from Sun: ~5 A.U. Gravity = 2.53x Earth’s Orbital Period: ~12 earth years

Composition: Molecular hydrogen (H 2 ) Helium Trace amounts of CH 4, NH 3 and H 2 O

The Great Red Spot A large hurricane-like storm that has been around for over 300 years Two earths could fit inside

Belts and Zones Belts are the dark colored bands Zones are the light colored bands Caused by convection currents

Where does the energy come from? Sun’s radiation (small) Lightning discharges (small) Internal heat source* *Jupiter gives off more than it gets from the Sun

In 1994 Comet Shoemaker- Levy (22 pieces of it) smashed into Jupiter leaving the dark spots seen in this photo

95x more massive than Earth 9.5x Earth’s radius 27  axial tilt Distance from Sun: 9.5 A.U. Orbital Period: 29 years Gravity: 1.1x Earth’s

Gases: Molecular Hydrogen (H 2 ): 92% Helium: 7.4% Some of the helium liquefied and sank to interior Trace amounts of CH 4 and NH 3

Rings are wide but thinRings are wide but thin About 106,000 km wideAbout 106,000 km wide Thickness of rings: a few hundred metersThickness of rings: a few hundred meters Composition mainly water, ice, and carbon compounds and is not uniform across ringsComposition mainly water, ice, and carbon compounds and is not uniform across rings Sizes range from centimeters to metersSizes range from centimeters to meters Rings structured into ringlets and gapsRings structured into ringlets and gaps

The Roche Limit: Any object will break apart by tidal forces if it gets too close to the planetAny object will break apart by tidal forces if it gets too close to the planet Distance of breakup is called the Roche limit and is 2.44 planetary radiiDistance of breakup is called the Roche limit and is 2.44 planetary radii For rings to persist they must be replenishedFor rings to persist they must be replenished Existence of side-by-side ringlets of different compositions indicates rings supplied by varied comets and asteroidsExistence of side-by-side ringlets of different compositions indicates rings supplied by varied comets and asteroids

Channels cut by running liquid Evidence of thunderstorms Atmospheric pressure 50% > than earth’s Ethane (C 2 H 6 ) lakes confirmed Hydrocarbon dunes

Reflection of Sunlight off Titan Lake

Discovered in 1781 by William Herschel Composed of 83% hydrogen, 15% helium, 2% methane Winds up to 360 mph Mean cloud temperature = -193°C

Distance from Sun: 19 A.U. Period = 84 years Blue color due to methane in atmosphere Mass = 14.5x Earth’s mass At least 22 moons

Diameter = 4x earth’s Ring system Axial tilt = 98°; Uranus is on its side! Magnetic Poles tilted > 60° with respect to its axis

Discovered in 1846 by Johann Galle A day on Neptune is 16 hours and 6.7 minutes Diameter = 4x earth’s winds blow up to 2,000 kph (1,200 mph) an hour

Distance from Sun: 30 A.U. Period = 164 years Blue color (methane) Mass = 17x Earth’s mass Ring arcs Neptune has cloud beltsNeptune has cloud belts

One of its six moons is TritonOne of its six moons is Triton Triton’s orbit is retrogradeTriton’s orbit is retrograde Triton has an atmosphereTriton has an atmosphere At least one geyser caught in eruption by the passing Voyager IIAt least one geyser caught in eruption by the passing Voyager II