Fifty miles below the cloud tops, we could expect thunderstorms, lightning, and rain. But in contrast to Earth, individual jovian storms and weather systems sometimes last for months, years, or even centuries. The Great Red Spot, for example, has existed for at least the 300 years that we've been aware of it. The latest data from Galileo also shed new light on the auroras that glow in a narrow ring around the Jupiter's poles. The auroras are created when charged particles collide with atmospheric particles, causing them to light up.
New images show the nightside aurora for the first time.
However, we now know that the auroral arc on Jupiter is thin and patchy, and we can also estimate its altitude is between 300 and 600 kilometers. These auroras had previously been viewed in ultraviolet light by the Hubble Space Telescope, and in infrared light by Earth-based telescopes, but Galileo was able to capture images of the auroras in visible light and from a closer vantage point. Images and other data received from Galileo are posted on the Galileo home page on the World Wide Web. The researchers conclude that Pathfinder landed during a period when rapid changes in the regional distributions of dust and clouds were taking place on Mars. The team suggests that the dust seen in the skies over Pathfinder may have diffused toward the landing site from the now dissipated dust storm in Valles Marineris.