Geminid (left) and comet 17P/Holmes (lower right)
|Parent body||3200 Phaethon|
|Constellation||Gemini (near Castor)|
|Right ascension||07h 28m|
|Occurs during||December 7 – December 17|
|Date of peak||December 14|
|Zenithal hourly rate||75+|
See also: List of meteor showers
The Geminids are a meteor shower caused by the object 3200 Phaethon, which is thought to be a Palladian asteroid with a "rock comet" orbit. This would make the Geminids, together with the Quadrantids, the only major meteor showers not originating from a comet. The meteors from this shower are slow moving, can be seen in December and usually peak around the 13th - 14th of the month, with the date of highest intensity being the morning of the 14th. The shower is thought to be intensifying every year and recent showers have seen 120–160 meteors per hour under optimal conditions, generally around 02:00 to 03:00 local time. Geminids were first observed in 1862, much more recently than other showers such as the Perseids (36 AD) and Leonids (902 AD).
The meteors in this shower appear to come from a radiant in the constellation Gemini (hence the shower's name). However, they can appear almost anywhere in the night sky, and often appear yellowish in hue. Well north of the equator, the radiant rises about sunset, reaching a usable elevation from the local evening hours onwards. In the southern hemisphere, the radiant appears only around local midnight or so. Observers in the northern hemisphere will see higher Geminid rates as the radiant is higher in the sky. The meteors travel at medium speed in relation to other showers, at about 22 miles per second, making them fairly easy to spot. The Geminids are now considered by many to be the most consistent and active annual shower. Geminids disintegrate while at heights above 38 kilometres (24 mi).
|Year||Active||Peak of shower||ZHRmax||Lunar phase|
|2006||December 7–17||Dec 14th||115||33% waning crescent|
|2007||Dec 15th||122||28% waxing crescent|
|2008||Dec 14th||139||96% Full moon|
|2009||Dec 13th||120||10% new moon|
|2010||December 7–17||Dec 14th||127||57% first quarter|
|2011||Dec 14th||198||86% waning gibbous|
|2012||December 4–17||Dec 14th (predicted ZHR=120 Dec 13th)||117||1% new moon|
See also 
- Gary W. Kronk. "Observing the Geminids". Meteor Showers Online. Retrieved 2012-11-14.
- Moore, Patrick; Rees, Robin (2011), Patrick Moore's Data Book of Astronomy (2nd ed.), Cambridge University Press, p. 275, ISBN 0-521-89935-4.
- "IMO Meteor Shower Calendar 2012: Geminids (GEM)". International Meteor Organization. Retrieved 2012-12-13.
- Brian G. Marsden (1983-10-25). "IAUC 3881: 1983 TB AND THE GEMINID METEORS; 1983 SA; KR Aur (Circular No. 3881)". Central Bureau for Astronomical Telegrams. Retrieved 2009-05-18.
- Victoria Jaggard (2010-10-12). "Exploding Clays Drive Geminids Sky Show?". National Geographic Society. Retrieved 2010-10-18.
- Jewitt, David; Li, Jing (2010). "Activity in Geminid Parent (3200) Phaethon". arXiv:1009.2710 [astro-ph.EP].
- "Radiant (Northern vs Southern)". NASA Meteor Watch on Facebook. 2012-12-12. Retrieved 2012-12-14.
- "NASA All Sky Fireball Network: Geminid End Heights". NASA Meteor Watch on Facebook. 2012-12-11. Retrieved 2012-12-11.
- "Geminids 2006: visual data quicklook". International Meteor Organization. 2007-04-25. Retrieved 2012-12-13.
- "Geminids 2007: visual data quicklook". International Meteor Organization. 2008-08-10. Retrieved 2012-12-13.
- "Geminids 2008: visual data quicklook". International Meteor Organization. 2009-01-02. Retrieved 2012-12-13.
- "Geminids 2009: visual data quicklook". International Meteor Organization. 2010-04-19. Retrieved 2012-12-13.
- "Geminids 2010: visual data quicklook". International Meteor Organization. 2012-09-19. Retrieved 2012-12-13.
- "Geminids 2011: visual data quicklook". International Meteor Organization. 2012-01-18. Retrieved 2012-12-13.
- "Geminids 2012: visual data quicklook". International Meteor Organization. 2012-12-21. Retrieved 2012-12-21.
- NASA Meteor Watch 2012:
- Allsky cameras observed 328 bright Geminids - notice how similar they are to the orbit of the asteroid 3200 Phaethon (purple orbit)
- Composite view of meteors detected in the skies over Marshall Space Flight Center (MSFC)
- Spectacular Geminid, brighter than the Full Moon (video 2012-Dec-14 07:28 UT)
- Meteoroid Environment Office: 53 meteor orbits last night of which 18 were Geminids
- Worldwide viewing times for the 2012 Geminids meteor shower
- NASA meteor flux estimator (Leonid MAC Meteor Shower Estimator)
- 2004 Geminids
- 2006 Geminids
- ShadowandSubstance.com: Geminids animated for 2010
- "Weird Geminids," NASA, 7 December 2001
- Google group search for Geminids, sorted by date
- Amateur observations of the Geminids
- Triangulation of a Geminid Meteor by Crayford Manor House AS
- ScienceCasts: Rock Comet Meteor Shower (Science@NASA YouTube channel : Nov 29, 2012)