Up for another early morning meteor shower? Then get ready for the Eta Aquarids (AY-tuh ah-QWAR-ids) which peak tomorrow in the quiet hours before dawn. This is a fairly big event for southern hemisphere observers who might see up to one meteor a minute during tomorrow morning's maximum. The radiant or point in the sky from which the meteors will appear to originate is much higher for southern latitudes. Morning twilight also begins later allowing for more viewing time.
The higher the radiant, the more meteors. A low radiant means most of a shower's meteors are out of view, streaking away below the horizon. At latitude 50 degrees north the viewing window lasts 1 1/2 hours with the radiant low in the southeastern sky; at 40 degrees north, it's a little more than 2 hours. If you live in the southern U.S. you'll have nearly 3 hours of viewing time with the radiant 35 degrees high.
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Across the middle north latitudes expect to see about 10 very fast meteors an hour. Eta Aquarids, which are the dusty remains of numerous visits of Halley's Comet to the inner solar system, tear across the sky at over 147,000 mph (237,000 km/hr). Slower meteors are often yellow or orange; these will flare white as they're incinerated by the atmosphere.
Earth crosses Halley's orbit twice a year. Each time, bits of the comet collide with our atmosphere and burn up. In mid-October we'll encounter Halley's orbit again and re-visit the comet's dust trail as the Orionid meteor shower .
Tomorrow morning the crescent moon will also be out - it eases up over the tree line about the time dawn begins - and a special guest, Comet Lemmon , located about one "fist" to the moon's left. While visible in binoculars as a dim, fuzzy patch of light, a telescope should show the comet's bright head and diffuse tail. The radiant is located near the star Eta Aquarii well to the right of the familiar Great Square of Pegasus.
Meteor shower members can appear in any part of the sky, but if you trace their paths in reverse, they'll all point back to the radiant. Other random meteors you might see are called sporadics and not related to the Eta Aquarids.
For most mid-northern sky watchers, the best time to watch will be about 2 1/2-3 hours before sunrise. (Find your sunrise time HERE ). Even if Aquarius is very low or hasn't risen yet, you can still catch a few meteors before twilight brightens the sky. You might even get lucky and spot an Earth-grazer, a slow-moving meteor skimming the upper atmosphere nearly parallel to the ground. They're best seen around the time the radiant rises. Keep an eye out for them.
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The Eta Aquarid shower has a broad peak, so if it's cloudy tomorrow, try again on Monday or Tuesday. You're likely to catch at least a few. All you need for equipment are your eyes, a comfy lawnchair and a reasonably dark sky. Face east or south for the best view. Good luck!
