Jupiter is the largest planet, and although much further away, is second only to Venus in terms of its apparent size and brightness in the sky. This consistency means it is easy to see for long periods of time, and lead to the Greeks naming after the king of their gods, even though they did not actually know that it is the largest planet.
It has no solid surface and its atmosphere is full of violent storms, one of which, the Great Red Spot, has been around for over 300 years. A good pair of binoculars will reveal the two principle cloud belts, and a bigger telescope allows the ever changing weather patterns to be studied.
In addition, Jupiter has 4 large "Galilean" moons, discovered by Galileo and of comparable size to our own Moon - Io, Europa, Ganymede and Callisto. These orbit in periods ranging from 2 to 17 days in a plane very close to the plane of the Solar System so they seem to shuttle back and forth across the Jupiter system. With luck, or prior knowledge of the timing, they, or their shadow, can be seen passing across the face of Jupiter, or be eclipsed when they pass behind Jupiter or into its shadow. Although they appear even in a telescope as little more than a point of light, each is a world with its own character, and Europa is a good candidate for harbouring life in an ocean thought to lie beneath its icy surface.
There is always plenty to see on and around Jupiter, even in binoculars or a small telescope.
|Distance from Sun (Million km):||741 (min)||816 (max)|
|Min. Distance from Earth (Million km):||625|
|Orbital Period:||11.9 years|
|Mean Interval between Oppositions:||399 days|
|Diameter (km):||142,200 (equatorial)||134,700 (polar)|
|Rotation Period:||9h 50m|
|Apparent Diameter (arc seconds):||50 (max), 30 (min)|
|Max. Apparent Brightness (magnitude):||-2.6|
Images: 2003 to 2004 appearance
Images: 2002 to 2003 appearance
|Jet Propulsion Laboratory Jupiter pages|