Thousands of images from professionals and amateurs are posted on the Internet. This one was made on March 9 with a Pentax camera by a group at Pearson College Observatory near Victoria, British Columbia, Canada.

Comet Hale-Bopp's spectacular passage through the solar system has captured the rapt attention of scientists and casual skygazers alike. From orbiting observatories like the Hubble Space Telescope and ground-based telescopes, such as those at Palomar and the European Southern Observatory, to amateurs equipped with telescopes, binoculars, opera glasses--or just the naked eye--everyone is watching Hale-Bopp. Interest in this visitor from deep space is peaking as the comet nears its closest point to the sun on April 1.

Hale-Bopp, which was first spotted by amateur astronomers Alan Hale and Thomas Bopp on July 23, 1995, has more than lived up to its promise of being one of the century's "great comets." Clearly visible to the naked eye, it blazes so brightly that it can be seen even before sunset and after dawn. At perihelion on April 1, Hale-Bopp's double tail will be at its most vibrant as the sun's warmth speeds the evaporation of the comet's frozen nucleus.

The show in the heavens is only part of the picture. Hale-Bopp has also created a sensation on the Internet. There are a multitude of Web sites containing information on Hale-Bopp; they are attracting so many visitors that they are causing a traffic jam on the Internet. A Hale-Bopp homepage set up at NASA's Jet Propulsion Laboratory was logging more than 1.2 million visitors a day over Easter weekend and had set up two mirror sites.

Don't miss an opportunity to see Hale-Bopp with your own eyes--it won't pass by again for another 4,000 or so years. But if it's a cloudy night, a bit of Web surfing can be almost as good. Thousands of images are posted on various Web sites--some almost in real-time, such as NASA's Comet Watch. And, even if skies are clear, a tour of a few Web sites is well worth the effort. You can check out the latest research findings, find out when and where Hale-Bopp is visible in the sky, and get advice on how to make your own pictures.

Spinning in Space

The Internet also makes it possible to view this cosmic wanderer in ways not possible with the human eye. Because Hale-Bopp was unusually bright when it was still a great distance away, well outside the orbit of Jupiter, it has given scientists their best view ever of a comet. And they have recorded its progress with a variety of instruments that capture changes in Hale-Bopp's nucleus in a broad range of wavelengths, from infrared to ultraviolet. Other researchers have created animations that allow us to observe these changes over time. These data provide valuable clues to the composition and structure of comets, which are believed to be remnants from the formation of the solar system, about 4.6 billion years ago.

New research findings about Hale-Bopp are being released almost daily. In its March 28 issue, the journal Science published a series of seven research papers about Hale-Bopp observations. Included was a report on a year-long series of observations by the Hubble Space Telescope of ultraviolet light emitted by Hale-Bopp.

The Hubble team recorded a number of unprecedented events from this unusual comet. The investigators observed the comet going through a sudden brief outburst; in little more than an hour the amount of dust being spewed from the nucleus increased at least eightfold. "The surface of Hale-Bopp's nucleus must be an incredibly dynamic place, with 'vents' being turned on and off as new patches of icy material are rotated into sunlight for the first time," says Harold Weaver, a Johns Hopkins University astrophysicist who headed the study.