Astronomers say it is unlikely such a comet will ever come this close to Earth again during Hubble's planned operational lifetime. Since Hubble is not actively controlled from the ground and the comet's position is not precisely known, viewing the speeding visitor will be especially tricky. The telescope will be preprogrammed to point at a selected spot in the sky where the comet will be at a specific time. Planned Hubble science observations of Comet Hyakutake include high-resolution imagery and ultraviolet spectroscopy. Near the time of the comet's closest approach, Hubble should be able to see details as small as four miles across.
Astronomers also hope to see jets of dust emerging from the comet's nucleus.
Although NEAR offers a different vantage point from Hubble, its camera was not designed to image objects at such large distances. These ices are composed primarily of water. Spectral observations of the molecules vaporized from the nucleus should provide samples of molecular abundances that were present at the time of the formation of the Solar System. This home page allows anyone with access to a computer and a modem to post and observe Hyakutake images, track the progress of the comet, converse with NASA experts, learn about astronomy and participate in experiments. Students will control the telescope and receive their images via telephone lines at their schools, using desktop computers and commercial software.