How many comets have scientists given names to? Why are some named and not others?

1 Answer
Feb 1, 2016

Many comets are named after scientists and all known comets have been given names.


All known comets have names. There are however a number of different naming conventions.

Th early comets were named after the year "Comet of 1702", "The Great Comet of 1882". Great comets were particularly visible.

Comets are also named after their discoverers. Edmond Halley predicted the return of a comet which was named after him. The 9 comets Shoemaker-Levy 1-9 were named after its discoverers.

Other comets are given names based on the year of discovery. Before 1994 a lower case letter was added to the year - Comet 1969a, Comet 1969b.

The modern system uses names such as P/2015 W2, P/2016 A7.
The P/ means that it is a periodic comet with a period less than 200 years. This is followed by the year of discovery. This is followed by the half month of discovery where A is the first half of January and W is the last half of December. This is followed by the sequence within the half month. So P/2016 A7 is a periodic comet which was the 7th discovered in the first half of January 2016.

Some comets have multiple names, especially if it has been discovered several times before it was realised that a comet is the return of a previously discovered comet.