Jupiter


Mass (Earth=1)318
Equatorial diameter (km)143,000
Period (years)11.9
Mean distance from Sun, 106 km778
Density (water=1)1.31
Surface gravity m/s222.9
Moons

With over twice as much mass as all the other planets and moons combined, Jupiter still has 50 times too little mass to be a star. It is 318 times as massive as the Earth. It is mostly composed of hydrogen and helium, but is thought to have a heavy element core on the order of 10 times the mass of the Earth.

The Great Red Spot, larger than two Earths, rages like a hurricane in Jupiter's turbulent atmosphere. Heat from Jupiter's 29,700°C (53,500°F) core keeps the atmosphere churning.

Voyager photographs showed extensive lightning activity in the atmosphere of Jupiter, and uv photographs indicate auroral activity.

Planetary data
 Index

Jupiter Concepts

Solar System Illustration

Solar System Concepts

Reference
de Pater and Lissauer
Ch 1
 
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Jupiter's Moons

Montage of Jupiter and the Galilean satellites Io, Europa, Ganymede and Callisto. The images are not to scale, but are in their relative positions. At upper left, the reddish Io is nearest Jupiter. Then Europa in center, then Ganymede and Callisto at the lower right. Image credit NASA, Jet Propulsion Laboratory. These images are from Voyager I.
Name
Distance from Jupiter
Orbit Period
Size
106 m
Jupiter radii
(days)
(Longest
diameter, km)
Metis
128
1.79
0.29
40
Adastea
129
1.80
0.30
20
Amalthea
181
2.54
0.50
260
Thebe
222
3.10
0.67
100
Io
422
5.90
1.77
3640
Europa
671
9.38
3.55
3130
Ganymede
1,070
15.0
7.15
5270
Callisto
1,880
26.3
16.7
4800
Leda
11,100
155
239
10
Himalia
11,500
161
251
170
Lysithea
11,700
164
259
24
Elara
11,700
164
260
80
Ananke
21,200
297
631*
20
Carme
22,600
316
692*
30
Pasiphae
23,500
329
735*
36
Sinope
23,700
332
758*
28
* Indicates retrograde orbit.
The four largest moons are comparable to the Earth's Moon in size. They are referred to as the Galilean moons. Their orbits are direct (in the same direction as the planet's rotation), their orbits are roughly circular, and they lie close to Jupiter's equatorial plane. Io and Europa have thick rocky mantles surrounding iron/iron sulfide cores. Ganymede and Callisto are less dense, with water and water ice accounting for as much as half of their masses. Ganymede does have a small metallic core, as evidenced by the fact that it has a magnetic field, but Callisto is apparently a largely undifferentiated mixture of rock and ice.

Additional Data for the Galilean Moons

Name
Mass
(Earth moon masses)
Density
kg/m3
Io
1.22
3500
Europa
0.65
3000
Ganymede
2.02
1900
Callisto
1.46
1900

The outer moons are in two groups of four each at about the same orbit radius. The moons of the inner group move in eccentric, inclined orbits at about 11 million kilometers, and those of the outer group move in eccentric orbits at about 22 million kilometers which are retrograde to the planets rotation. It is likely that each group came from the breakup of a single body which was captured by Jupiter's gravity.

Eclipse on Jupiter
 Index

Solar System Illustration

Solar System Concepts

References
Chaisson & McMillan,
Ch 11.
 
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