This time-lapse movie of Neptune was assembled from combining NASA Hubble Space Telescope images taken over a 15-hour period. The movie shows a dynamic atmosphere and captures the fleeting orbits of Neptune's satellites. The natural color and enhanced color views of Neptune were assembled from images in 14 different colored filters. This allows atmospheric features to be seen above Neptune's methane haze, which gives the planet its blue-green color.
The animation has four sections, each one corresponding to approximately one rotation of Neptune.
The first section shows Neptune and its largest satellite Triton, which is about as large as our moon. Probably a captured Kuiper Belt object, Triton orbits Neptune in a "backwards" or retrograde path relative to the other major satellites, and opposite to Neptune's rotation. The view is close to what a human eye would see looking through the Hubble Space Telescope.
The second scene zooms in on Neptune, and the colors have been enhanced to better show the subtle detail of clouds in Neptune's atmosphere.
The third scene has the spectral region of light changed from the visible to special methane bands in the near infrared. Most of Neptune's atmosphere becomes very dark, except for high-altitude clouds.
The fourth scene traces the satellite orbits. Four of the small, inner satellites are visible orbiting Neptune. Dutifully obeying Kepler's laws of planetary motion, the outer moons take longer to revolve around Neptune than the inner ones. From outside to inside, these satellites are Proteus, Larissa, Galatea, and Despina. These moons are so faint that only the longest Hubble exposures can capture them.
The outermost layers of Neptune's thick atmosphere do not rotate like a solid body. The polar atmospheric regions finish a full rotation in a speedy 15 hours, while the equatorial regions lag behind, taking more than 18 hours for a complete circuit of the planet.
Publication: September 1, 2005