Orionids


The Orionid meteor shower, usually shortened to the Orionids, is the most meteor shower associated with Halley's Comet. The Orionids are so-called because the point they appear to come from, called the radiant, lies in the constellation Orion, but they can be seen over a large area of the sky. Orionids are an annual meteor shower which last approximately one week in late October. In some years, meteors may occur at rates of 50–70 per hour.

History

Meteor showers first designated "shooting stars" were connected to comets in the 1800s. E.C. Herrick made an observation in 1839 and 1840 about the activity present in the October night skies. A. S. Herschel produced the first documented record that gave accurate forecasts for the next meteor shower. The Orionid meteor shower is produced by the well known Halley's Comet, which was named after the astronomer Edmund Halley and last passed through the inner solar system in 1986 on its 75- to 76-year orbit. When the comet passes through the solar system, the sun sublimates some of the ice, allowing rock particles to break away from the comet. These particles continue on the comet's trajectory and appear as meteors when they pass through Earth's upper atmosphere. Halley's comet is also responsible for creating the Eta Aquariids, which occur each May.
YearActivity Date RangePeak DateZHRmax
1839October 8–15
1864October 18–20
1981October 18–21October 2320
1984October 21–24October 21–24
2006October 2November 7October 21–2423 with peaks at 67
2007October 20–24October 21 70
2008October 15–29October 20–22 39
2009October 18–25October 2245
2010October 2338
2011October 2233
2012October 2 — November 7October 20 and October 2343
2013October 22~30
2014October 2 — November 7October 2120?
2015October 2 — November 7October 20–21N/A
2016October 2 — November 7October 21~10–20

* This meteor shower may give double peaks as well as plateaus, and time periods of flat maxima lasting several days.

Meteor shower and location

The radiant of the Orionids is located between the constellations Orion and Gemini (in the south-eastern sky before dawn, as viewed from mid-northern latitudes. The most active time of the meteor shower was stated by Telegraph.co.uk to be in the early morning of October 21, 2009 Eastern Standard Time in the United States or in the United Kingdom. Universe Today reported that the meteor shower arrived at per hour on the morning of the 21 when showing was predicted to be at its height, however compared to previous showers in years past, the trail of 2009 appeared narrower without branching out. Observers observing the small meteor "Halleyids" at Alabama's Space Flight Center saw streaks radiating in all directions with the naked eye.

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