National Geographic : 1999 Sep
particles traveling along the planet's magnetic field lines strike the upper atmosphere and make hydrogen gas glow some 155 miles above Jupiter's cloud tops. Computer imaging creates a false-color glimpse between two cloud layers (below) just north of Jupiter's equator. Dark blue indi cates an area largely clear of clouds, where dry air descends deeper into the atmosphere. Ammonia ice crystals form the upper haze; its distance above the lower clouds is exag gerated in the image. Galileo also captured a convective thunderstorm (right) northwest of the Great Red Spot.