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The annual Orionids meteor shower peaks on October 21st but unfortunately a 65% illuminated waning gibbous Moon positioned close to the radiant will significantly interfere. Normally regarded as quite a strong shower, the Orionids is active between October 2nd and November 7th. In the past rates of up to 70 per hour have been observed but the shower has recently not been so strong; a figure between 20 and 25 is currently the norm.

Nucleus of Halley's Comet (credit - Halley Multicolor Camera Team, Giotto Project, ESA)

Parent Comet

The Orionids parent object is the most famous comet of all, Halley (1P/Halley). Of the two annual meteor showers associated with Halley, the Orionids is the more prolific. The other shower, the weaker Eta Aquariids (Eta Aquarids), occurs during May.

Although Halley is now in the outer Solar System and will not return to Earth until 2061, it's worth remembering that every Orionids meteor is a small part of the famous comet streaking through and subsequently burning up in the atmosphere.

Radiant

The radiant of the Orionids is located in the northeast part of Orion, close to the Gemini border. Since Orion straddles the celestial equator, it's one of the few annual showers that's well placed for observation from most locations on Earth.

Sadly this year is bad year for the shower. The problem of course is the Moon, which on October 21st passes only a couple of degrees north of the radiant, hence washing out all but the brightest meteors. However, the shower is reliable and often produces bright fast meteors that streak through the sky as they hit the atmosphere at speeds of 235,000 km/hour (145,000 miles/hour).

As with all annual meteors showers it's best not to look directly at the radiant. A good tip is to try and position yourself in such a way that the Moon is out of view, for example behind a building or group of trees, hence offering the best chance of catching a few meteors as they shoot by.

View towards east around midnight from mid-northern latitudes on night of October 21st (credit:- stellarium / freestarcharts)

Orionids Radiant and Star Chart (credit:- freestarcharts)

Orionids Radiant and Star Chart - pdf format (credit:- freestarcharts)

Orionids Data Table 2016

Meteor shower nameOrionids
Meteor shower abbreviationORI
Radiant constellationOrion
ActivityOctober 2nd -> November 7th
Peak DateOctober 21st
RA (J2000)6hr 20m
DEC (J2000)+16d
Speed (km/s)66
ZHR 20 to 25 (can vary between 20 and 70)
RatingBright
Parent body1P/Halley
NotesMost prolific meteor shower associated with Halley's Comet

Comet 1P/Halley Data Table (at epoch February 17th, 1994)

Name1P/Halley
TypeComet
ClassificationHalley-type comet (NEO)
DiscovererPrehistoric, Edmond Halley first recognised the periodicity
Discovery datePrehistoric
Aphelion (AU)35.0823
Perihelion (AU)0.58598
Semi-major axis (AU) 17.8341
Eccentricity0.96714
Orbital period (years)75.3175
Inclination (degrees) 162.263
Longitude of ascending node (degrees)58.4201
Last perihelion February 9th, 1986
Next perihelion July 28th, 2061
NotesHalley's comet, the most famous of all comets