The Sun's energy heats the atmosphere and the oceans, which then drive the weather on Earth. On Neptune, though, the Sun is 900 times dimmer. What then causes the monster storms and the 900-mph equatorial winds captured here in this Hubble image? Astronomers are trying to find out. Using Hubble and NASA's Infrared Telescope Facility in Hawaii, a team of scientists created a time-lapse rotation movie of Neptune that allowed them to watch the ebb and flow of the distant planet's weather. They measured Neptune's circulation, mapped its cloud tops and discovered distinct bands of weather that run parallel to the planet's equator. These bands encircle the planet and, in some respects, may be similar to the equatorial region of the Earth where tropical heat provides the energy to make clouds.