Summary: Halley ’s Comet has made a big mess. The comet has been passing close to the Sun for at least two millennia. And on each pass it sheds a little more debris — tiny grains of rock that are released when ice at the comet’s surface vaporizes. We see evidence of that messiness every October as the Orionid meteor shower, as some of those bits of debris slam into the upper atmosphere, producing the glowing streaks of light known as meteors. The shower should be at its best the next couple of nights. And the Moon sets by around midnight, so it won’t pollute the sky with light during the peak meteor-watching hours. Although the Orionids are always one of the year’s best showers, just how good varies. Some years, the shower produces a peak rate of only about a dozen or so meteors per hour. Other years, it’s several times that rate, with an average of around a couple of dozen. And just how long the peak lasts varies, too — from a few hours to a couple of days. That’s because the trail that Halley has left behind is complicated. There are streamers and voids within the trail that are tough to predict. So while just about every year is a good year for the Orionids, some years are better than others. With that in mind, the Orionids are always worth a look. The best viewing hours are after midnight, when your part of Earth turns into the meteor stream. Find a dark but safe skywatching site, then look up — for fireworks from a messy comet. Script by Damond Benningfield, Copyright 2012 For more skywatching tips, astronomy news, and much more, read StarDate magazine.
