Last Chance for the Leonids till 2099

If only the weather will cooperate, there's a sky show tonight and Tuesday morning that you won't want to miss. Meteor showers occur when the Earth passes through debris from the orbit of a comet, in this case, it is comet 55P/Tempel-Tuttle. When a comet swings in around the Sun, parts of it get blown off as the comet heats up. If the comet has made many trips around the Sun, the orbit ends up with a lot of debris, some in clouds. When Earth passes through these debris clouds, we see a meteor storm and that's exactly what is in store for us tonight and tomorrow. When a piece of debris (often just the size of a grain of sand,) enters the Earth's atmosphere it burns up and we see this as a meteor, or shooting star.

The Leonid meteor shower is an annual event this time every year, but it usually produces only about ten meteors per hour, but about every 33 years, the shower peaks and produces hundreds and sometimes thousand of meteors per hour. This is the last year for one of these peaks and there won't be another one until about 2099 because Jupiter will be changing the comet's orbit. Fred Peters, retired NASA JPL astronomer described it as "the comet's orbit will be affected by the gravity of Jupiter which will pass close by. The comet will be pushed out of it's normal orbit and into one which does not come so close to the Earth, and so there will be no more Leonid storms until about 2099. That makes this event a once in a lifetime thing to see!"

The Leonids are different from most meteor showers. Joe Rao, on camera meteorologist from West Chester, New York explains. "Leonids appear ultrafast compared to the meteors of other showers, for this stream's particles enter our atmosphere at 71 kilometers per second (near the theoretical speed limit for particles belonging to our solar system). Because of their tremendous speeds, Leonids can be extremely bright and are often tinged with hues of blue or green. Roughly half leave luminous vapor trains -- some hanging in the air five minutes or more.

The first storm is expected to take place around 10:43 to 11:09 pm Monday night. Our area will not get the best show of this one, as Leo is just rising and the near full moon will be high in the sky, obscuring dimmer meteors. However, the angle the meteors will be coming in makes it perfect for what's called Earth grazing meteors, fast bright trails which shoot across the sky for a long way. Numbers are estimated to be around one to two thousand per hour, but again, the moon's light will obscure dimmer meteors.

The second storm is the one we should really look forward to because we are in a prime spot to see it. The time for the second storm is between 5:30am and 5:46am on Tuesday morning. But Rao is encouraging people to stay up and watch later. "Even so, all viewers are well advised to keep a Leonid watch right up through sunrise, since at past Leonid outbursts brilliant fireballs have been perceived in bright twilight, even broad daylight."

Numbers for the second peak are estimated to be somewhere between 2600 and 10,000 per hour! Leo will be nearly overhead (meteor showers appear to originate from the constellation they are named after.) The moon will be low in the west and so not lightning the sky so much. All of North America is favored for this second peak. It's a free sky show you won't want to miss!

For times, star maps, viewing tips and additional information about meteors, go to http://starryskies.com/The_sky/events/meteors/.

Constellations

The Solar System