Comet Hale-Bopp bebops across the sky

"When we look at comets today, we're essentially looking backwards in time and seeing the physical and chemical conditions that existed at the time of the formation of the solar system."
Hal Weaver, Johns Hopkins University astronomer

"Dirty snowballs is what they are, chunks of ice and interplanetary dust mixed together."
Tom Bopp, comet co-discoverer

Stargazers of all levels of experience enjoyed the show this year as Comet Hale-Bopp zipped through the solar system, leaving a trail of dazzled astronomers in its wake.

The comet, estimated to have a nucleus 25 miles in diameter and a tail several million miles long, was thought to be the biggest and brightest to come near Earth since 1811.

It was easily visible to the naked eye for much of the year. Viewers in the Northern Hemisphere got their best shot at a sighting in the late winter and spring, and those in the Southern Hemisphere through the summer and into the fall.

Astronauts aboard the U.S. space shuttle Discovery enjoyed a special view of Hale-Bopp in August. They used an ultraviolet telescope to take vivid color pictures unfiltered by the Earth's atmosphere.

Scientists on the ground used infrared and radio telescopes to observe gases burning near the core of the comet.

The chunk of steaming ice, chemicals and dust was passing through on a multi-millennial trip around the sun. It traveled closest to the sun April 1, and came no closer to Earth than 122 million miles.

The mass dubbed Hale-Bopp last visited our solar system some 4,000 years ago, and is not expected back for more than 2,000 years.

The comet was named for two men who discovered it at about the same time on July 22, 1995: Alan Hale, a professional astronomer, at his home in southern New Mexico, and Tom Bopp, an amateur, in the Arizona desert.

Hale-Bopps's appearance was also linked to a mass cult suicide in California. The leader of the group calling itself Heaven's Gate and 38 followers killed themselves in March, saying they wanted to rendezvous with a spaceship they believed was following the comet.