Asteroid designation
An asteroid designation is the code or number given to an asteroid, such as 2008 TC3 or 101955 Bennu.
Each asteroid has an official label. When one is first found, it receives a provisional designation based on the date of discovery: a year, followed by letters and sometimes numbers. For example, 2008 TC3 was the 78th object found in the first half of October 2008. The first letter shows the half-month, and the second letter and number count the discoveries within it.
Once its orbit is well known, an asteroid receives a permanent number, given in order. Bennu is number 101955, and Vesta is number 4, because it was the fourth asteroid found, in 1807. Its discoverer may then propose a name, which must be approved by a committee of the International Astronomical Union.
Comets have their own system, such as 1P/Halley or C/2020 F3 (NEOWISE), with P for periodic and C for long-period. Meteorite names are separate and usually come from the place where the stone was found.
Related terms
Level: Enthusiast Teens and adults