...And estimating its size.The brightness of Hale-Bopp in the latest observations with the Hubble Space Telescope Hubble Space Telescope (HST), the first large optical orbiting observatory. Built from 1978 to 1990 at a cost of $1.5 billion, the HST (named for astronomer E. P. Hubble) was expected to provide the clearest view yet obtained of the universe. suggests that the comet's icy nucleus has a diameter as large as 40 kilometers-four times bigger than the nucleus of Comet comet [Gr.,=longhaired], a small celestial body consisting mostly of dust and gases that moves in an elongated elliptical or nearly parabolic orbit around the sun. Comets visible from the earth can be seen for periods ranging from a few days to several months. Halley. Although size alone doesn't guarantee a dazzling display, the large diameter bodes well for an impressive light show in 1997, notes Harold A. Weaver of Applied Research Corp. in Landover, Md. He cautions, however, that his Hubble calculation represents only a rough estimate, since the comet is far smaller than the tiniest feature-about 400 km in length-that the telescope can resolve at Hale-Bopp's distance from Earth. When Hubble imaged the comet on Oct. 23, it fortuitously for·tu·i·tous adj. 1. Happening by accident or chance. See Synonyms at accidental. 2. Usage Problem a. Happening by a fortunate accident or chance. b. Lucky or fortunate. caught Hale-Bopp in a relatively quiescent quiescent at rest; latent; the G0 stage of the cell cycle. state, 10 days after its last outburst. During that time, the comet's dusty halo was less pronounced, and more of the light seemed to reflect from Hale-Bopp's core. With the caveat that reflected light might have come from a small, unseen outburst elsewhere in the comet, Weaver speculates that the core could indeed be a whopper Whopper - WarGames . |
|
||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion