Today the comet attributed to the Draconids is found in the history of astronomy.
Comet 21P/Giacobini–Zinner lit up in the sky on October 31, 1998, as captured by the Kitt Peak 0.9 meter telescope. Credit: NASharp/NOAO/AURA/NSF
- Comet 21P/Giacobini–Zinner was first observed by Michel Giacobini at Nice Observatory on December 20, 1900.
- Its orbital period was revised to 6.6 years after its rediscovery by Ernst Zinner on October 23, 1913.
- The comet has been identified as the source of the debris stream responsible for the annual Draconid meteor shower in October.
- The International Comet Explorer (ICE) mission performed the first spacecraft-comet encounter with 21P/Giacobini-Zinner in 1985.
On December 20, 1900, astronomer Michele Giacobini observed a magnitude 10 comet while working at the Nice Observatory in France. Calculations done after their discovery showed that the comet had an orbital period of slightly less than seven years. When the German astronomer Ernst Zinner accidentally rediscovered the comet while observing variable stars on October 23, 1913, the calculations were revised: Comet 21P/Giacobini–Zinner has an orbital period of 6.6 years. It is also responsible for the debris that gives us the Draconid meteor shower every October. In 1985, the International Cometary Explorer (ICE) mission flew by comet 21P/Giacobini–Zinner in the first spacecraft/comet encounter.
