Sky-watchers are getting ready for a meteor shower from a celestial lion: The Leonids peak this weekend.
While this year's performance is expected to be dampened somewhat by the partially illuminated moon, there will still be a pretty sky show. Shooting stars will light the sky every few minutes at peak time, from late night Sunday, November 16, into the following pre-dawn hours.
Like their namesake, the Leonids are known to be quite temperamental. They have been known on rare occasions—every 33 years or so—to flare up into bona fide meteor storms, with hourly rates as high as a few hundred meteors.
During the last big storm in 2002, over 3,000 meteors fell per hour. But the granddaddy—and the root of the Leonids mythical status—was the 1833 storm where counts on one night went as high as 72,000 shooting stars per hour. Talk about a cosmic fireworks show!
While we don't expect the celestial lion to roar so loudly this year, it is still worth braving the chilly November weather and bundling up to see how the Leonids do perform. Meteor forecasting is still in its infancy, so there is always the chance of an unexpected uptick in numbers.
Like other meteor showers, such as the Perseids and Orionids, the Leonids happen when Earth plows through a trail of debris left in the wake of a comet orbiting the sun, in this case comet Tempel-Tuttle. When a comet gets close to the sun, melting ice releases pieces of dust, most no larger than a grain of sand, and deposits them in clumps.
Earth crosses paths with the orbiting debris of some comets annually, and each year some of the debris burns up in our atmosphere and creates meteors.
Occasionally a larger object, more like a pebble or even a boulder, will produce a brilliant fireball. The Leonids are known for these more spectacular meteors, and sky-watchers should be on the lookout for them.
Where will they appear in the sky?
The Leonids are so named because they seem to radiate from the constellation Leo, the lion, which rises above the northeast horizon in late evenings this time of year.
Shooting stars will appear to race across much of the night sky, but if you look carefully you can trace each one's path back to the constellation itself.
When is the best time to look up?
Best views will be during pre-dawn hours for all locations on Monday morning, November 17, when the Leo constellation appears to rise in the south to its highest point in the sky.
The waning crescent moon will be interfering with the show somewhat, since it rises around 2 a.m. local time in the eastern sky, just in time for the Leonids peak to kick in. So the best bet may be to catch some shooting stars earlier in the night, starting late Sunday night, before the moon creeps above the horizon.
What gear do I need?
Meteor showers are best enjoyed using just your naked eyes. Since the meteors can appear to zip across large tracts of the overhead sky, it's best to lie down on a reclining lawn chair back-to-back with an observing buddy so that as a team you can cover almost the entire sky.
Since it's November in the Northern Hemisphere, where it will appear the strongest, bundle up well with blankets. And don't forget the hot chocolate to help you enjoy the celestial fireworks show.