July 23, 2022
On this date in 1995, American professional astronomer Alan Hale and amateur astronomer Thomas Bopp independently discovered a new comet that was not yet visible to the naked eye. This comet was named Hale-Bopp after both discoverers and was best visible during 1997. Comet Hale-Bopp became one of the most widely observed comets of the 20th century due to its longevity – 18 months of visibility – and its extreme brightness.
An image of comet Hale-Bopp taken on April 4, 1997. It is possible to see both the white dust tail on the right and the blue ion tail to the left. Image credit: E. Kolmhofer/H. Raab/Johannes Kepler Observatory