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.
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.
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.
Orionids Data Table 2016
|Meteor shower name||Orionids|
|Meteor shower abbreviation||ORI|
|Activity||October 2nd -> November 7th|
|Peak Date||October 21st|
|RA (J2000)||6hr 20m|
|ZHR||20 to 25 (can vary between 20 and 70)|
|Notes||Most prolific meteor shower associated with Halley's Comet|
Comet 1P/Halley Data Table (at epoch February 17th, 1994)
|Classification||Halley-type comet (NEO)|
|Discoverer||Prehistoric, Edmond Halley first recognised the periodicity|
|Semi-major axis (AU)||17.8341|
|Orbital period (years)||75.3175|
|Longitude of ascending node (degrees)||58.4201|
|Last perihelion||February 9th, 1986|
|Next perihelion||July 28th, 2061|
|Notes||Halley's comet, the most famous of all comets|