Today we’re celebrating the birthday of the Hale-Bopp comet! This comet was first spotted by Alan Hale and Tomas Bopp 15 years ago today.

It became visible in the northern hemisphere in 1997 and provided a spectacular celestial show for those who were watching the night sky.

The Hale-Bopp comet was absolutely enormous!  The diameter of its nucleus was anywhere from 19-25 miles (most comets are less than 3!).

The sight of this comet gave both professional astronomers and casual stargazers a great deal of delight. For this reason, we’re celebrating the discovery of the Hale-Bopp comet on this Fun Fact Friday.