Most massive of the planets, gas-rich – larger than all the other planets combined

Shines twice as brightly as reflected sunlight would allow

• where does the extra energy come from?

Cloud formations, storms, and strong winds define the observed surface

• Great Red Spot (a 300 year-old storm)

• site of the Shoemaker-Levy cometary impact (1994)
  • 20 comet fragments impacted Jupiter, over a span of days
  • first evidence for water in the Jupiter atmosphere
  • do we see impact craters? other remnants?
  • was the atmosphere strongly affected?

Many major and minor moons

• major moons formed from a nebula around Jupiter (as the planets formed around the Sun)

• major moons are differentiated, heated by tidal forces (causing friction within the moons)

• Io: metallic core, rock, no water, no craters, and active volcanoes!

• Europa: rock and (thin) ice, liquid water below the surface

• Ganymede: rock and ice, geological activity (faults, craters)

• Callisto: rock and ice, liquid water below the surface

• minor moons, 10 kilometers in size, some with retrograde motion – accreted asteroids?

Rings, thin and reddish – made of moon dust?

If there were life on Jupiter, what would it be like? Could there be life on any of the moons?

	Io and Europa	Great Red Spot	Io	Europa
	Water Cloud Thunderstorm	White Cloud	Ganymede	Callisto
Images of Jupiter and its primary moons. [NASA]