The Orionid meteor shower will peak this weekend. Look for the greatest numbers of meteors to streak the sky in the dark hours before dawn on Saturday, October 20, and Sunday, October 21, with forecasters giving the nod to Sunday. Fortunately, the waxing crescent moon will set way before the prime time hours for watching the Orionids.
Look for Orion, Sirius and Venus in the southern sky before dawn
The best time for viewing for these fast-streaking Orionid meteors is between midnight (1 a.m. daylight saving time) and dawn the next few mornings. That time holds true no matter what time zone you’re in.
Our chart at top shows the radiant point in this annual shower – in the northern part of the famous constellation Orion. Orion is a large rectangle, with a distinctive row of three medium-bright stars in the middle. The brightest star in the sky, Sirius, is to the southwest of Orion on the sky’s dome. And the even brighter planet Jupiter beams to the northeast of Orion in October 2012. This constellation is well up in the southeast after midnight now, and it’s high in the south before dawn. We will have much more to say about Orion in the months to come, because it’s one of winter’s most prominent constellations.
Venus rises in the east about three hours before sunrise at mid-northern latitudes
In 2012, the dazzling planet Venus also lights up in the predawn darkness, along with the Orionid meteors. Simply look in the east to see the third-brightest celestial object, after the sun and moon. At present, Venus shines in front of the constellation Leo the Lion.
The meteors appear throughout a large area of sky. You don’t need to know how to recognize Orion or any other constellation to see them. But if you trace the paths of the meteors backwards, you’ll see they all seem to come from single point, called the radiant point. This is the point in the sky where we cross the comet’s orbit, kind of like the point in the distance where train tracks converge.
The radiant is above and outside Orion’s rectangle, but – again – you do not need to identify exactly where the radiant is to enjoy the meteors, or Orion!
Earth crosses the orbit of Halley’s Comet annually in October. The meteors are debris from this comet that enter Earth’s atmosphere and vaporize as they fall. Saturday and Sunday mornings will probably present the best viewing window, during the dark hours before dawn. Remember, the absence of the moon may enable you to see up to 20 Orionid meteors per hour.