Comet: A comet is a small body that orbits the sun. A comet is made of a coma, nucleus, and a tail. The coma surrounds the nucleus and is made of carbon dioxide, water vapor and other gas. The nucleus is made of solid ice, rock, and dust. The tail is comprised of dust and ionized gases and may extend for millions of miles.
Comet Hale-Bopp was one of the most-observed and brightest comets to appear from Earth in the 20th century. It was visible to the naked eye for a record eighteen months!
The comet was discovered by comet hunter Alan Hale from his driveway in New Mexico and by Thomas Bopp in Arizona, who was out looking for galaxies with his friends. At the time, it was farthest comet from Earth ever discovered as it was orbiting between Jupiter and Saturn when it was found. Scientific analysis determined that the nucleus of Hale-Bopp was apx. 25 miles in diameter, two to three times as large as Halley’s Comet. It appeared over 1,000 times as bright as Halley’s Comet did from the same location. In addition, this comet was revealed to have a sodium tail (as well as a gas and dust tail). This was the first time that scientists had seen sodium emitted from the tail of the comet. This sodium tail extended over 30 million miles in length. It was also the first time that scientists discovered argon (a noble gas) in a comet.
The Hale-Bopp Comet was also the first comet to be tracked via the internet, as millions of people visited the official NASA comet site to view pictures and updates. Scientists believe Comet Hale-Bopp will be visible to large telescopes until the year 2020, at which point it will be indistinguishable from distant galaxies. This long-period comet will not again be visible on Earth until apx. 4377. This means that before 1997, the last time the comet was visible on Earth was apx. 2215 B.C. Scientists think it may have nearly collided with planet Jupiter around that time.
In March of 1997, the Heaven’s Gate Cult chose the appearance of the Hale-Bopp comet as a signal to commit mass suicide in an attempt to leave their bodies and join a spaceship that some thought was following the comet. In all 39 people died.