Of all the solar system bodies, Jupiter is the largest. Its diameter, 88,730 miles is about one-tenth that of the Sun. Since its density is similar to the solar value, Jupiter's mass is about 1000 times less. In fact the planet has about a tenth the mass of the least massive stars known, placing it part way to being a star. The differences between Jupiter and a star arise simply because Jupiter was too small for nuclear processes to occur in its interior. The energy released when Jupiter condensed from the solar nebula was insufficient to raise the central temperature to that critical value at which the nuclear reactions which power stars could begin. Jupiter therefore offers a hint of how protostars might appear before they start hydrogen burning. As the photo shows, the planet is streaked by alternate dark and light belts. They lie along lines of latitude. The belts are generated by Jupiter's rapid rotation. Jupiter spins on its axis in 9 hours 50 minutes, with a speed of over 40,000 MPH. At higher latitudes the planet rotates more slowly, requiring 9 hours 55 minutes for one rotation, and thus shearing itself along the belts.

C11 / QuickCam VC
Photographic Power: 55x