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Jupiter
JupiterSol 5
Jupiter
Distance
from the Sun
  mil km778.33
  mil miles483.6
  AU 5.2028
Orbital Period
(length of year)
  Earth days4332.71
  Earth years 11.862
Local Days per Year  
rotations per orbit  
10,555
Length of day  
in Earth Time  
9h 51m
Axial Tilt   3.13
Orbital Inclination  
from Earth's orbit  
1.308
Orbital Eccentricity  
from circular  
0.0483
Sidereal Rotation  
in Earth days  
0.41354
Mean Orbital Velocity km/s   13.06
Visual Geometric Albedo .52
Vo or Object's Visible
Magnitude at Opposition
-2.70
Mean Radius km     71,492
Mean  
Diameter  

at Equator  
  km142,980
  miles88,732
  x Earth11.2
Mass   kg1.9 e+27
  x Earth317.8
Density (grams per cm3)  
Gravity x Earth  
Escape Velocity in km per sec  
Jupiter, king of the gods. The fifth planet out from the sun is best known for its many stripes, and giant red spot - a cyclonic storm, many times the diameter of the Earth. The average cloud temperature is -121C Atmospheric pressure: 700 millibars. Atmospheric composition: 90% Hydrogen and 10% Helium.

Jupiter has four main moons, the Galileans: Io, Europa, Ganymede and Callisto - discovered by Galileo in 1610. These may all be casually viewed by any modern over the counter telescope - appearing as common companion lights, augmenting Jupiter's superior brightness. Any respectable astronomical publication will post the expected positionings of the Fantastic Four. We are not, however, sadly, one of those; so we will not bother you with such things.

Io Europa

Io

Europa
Ganymede
Ganymede
Distance
(in miles)
Revolution
(in days)
Diameter
(in miles)
Gravity
(x Earth)
Io262,0001.772256.138
Europa417,0003.551951?
Ganymede665,0007.153268.145
Callisto1.170,00016.692983.124

Callisto

Callisto

There are gobs of other moons - about 70 at latest count. Grant you, not all of them are actual moons, per se - more like captured asteroids, which for whatever reason lack the good sense to plummet aimlessly into the Jovian atmosphere. Maybe they just like the view, as opposed to the infinite bleakness of space - and it probobly beats falling into The Sun. For safety's sake, the remaining mini-monsters are Jovially are referred to as satellites.

One reason why Jupiter seems to have collected so many strays is its proximity and tendancy to pass through giant asteroid fields - the gravity of a Gas Giant can be very persuasive. For the most part, The Trojans keep pace with Jupiter, leading and following its path around the sun - because if they don't, blammo.

The Trojans


The Solar System
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The Asteroid Belt Jupiter Saturn Uranus Neptune Pluto