The Leonid meteor shower

by Jeff Bowell, guest blogger

Weather and other circumstances permitting, people living in the Front Range might see a remarkable sight in the night sky this week.

leonid-meteor

Leonid Meteor Shower

The Leonid (“LAY-oh-nid”) meteor shower happens each year at about this time in November, but it’s always a toss-up as to how many meteors, or “shooting stars,” will be visible.  Weather, of course, is a factor – if it’s overcast, we’re out of luck.  However, the forecast for Tuesday night, the best time to see the Leonids, is looking good.

Some meteor showers happen at what most people would consider convenient viewing hours.  The Persied shower, for example, can be seen around August 10th – 12th, and provided you’ve wearing mosquito repellant and have a comfortable chair to sit in while viewing the northeast sky, the show – while always unpredictable – can be quite enjoyable…plus, you don’t have to stay up too late if you don’t want to.

The Leonids, on the other hand, aren’t known for convenience.  The shower occurs when the earth passes through the remnants (left-over debris) of the Comet Tempel – Tuttle.  The comet orbits the sun (as the earth does), but with a much differently shaped orbit.  The earth’s orbit around the sun is almost completely circular, while a comet’s orbit usually looks like a very s-t-r-e-t-c-h-e-d oval.

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Orbit of Comet Tempel-Tuttle

Comets, a.k.a. “Dirty snowballs”, as astronomer Fred Whipple once described them, leave a trail of cometary debris in their wake along their orbit, and the earth passes through this debris trail twice yearly.  There’s a part of the sky where the meteors appear to emerge from – astronomers call this the radiant.  For the Leonids, the radiant is within the constellation Leo, the Lion, an easily recognized constellation, once you get to know it.

That’s the good news.

The bad news is that if you want to see the Leonids at their best, you’ve got to be up during the “wee small hours” of the night.  I’ll get back to that later.

For now, it’d be a good idea for potential meteor shower viewers to get familiar with the constellation Leo.  Many people know the Big Dipper, of course, and some recognize Orion in the winter skies over Colorado.  Both are distinctive constellations.  Leo might well be new to most people, but it, too, has properties that make it easily recognized.

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Constellation Leo

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Constellation Leo

If you do a search online along the lines of “Constellation Leo”, you’ll find several examples (as I just did) of how the constellation appears in the night sky.  The most distinctive part of it is that portion representing the Lion’s head.  This “asterism” (not a constellation in itself) is to the right (west) of the constellation and resembles a “backwards question-mark” or “sickle.”  It’s easy to spot.  Other online sources (check for “Leonid meteor shower”) will give suggestions as for times you can see the shower, but no matter what happens, if you want to see it you’re either going to have to get up early  or stay up late.

As a long-time stargazer, I’ve got myself up in the middle of the night to see the Leonids.  Only once was it a spectacular display.  However, there have been some amazing displays recorded.  One Leonid shower in the early 1800s that was seen from New York State, was described by a viewer this way:

“…The stars fell like snowflakes in a blizzard.”

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Leonid Meteor Shower

That’s probably not what’s going to happen this time, but astronomers believe that this year’s Leonids may be better than past ones.  North America isn’t the best location to see the meteors at their anticipated peak performance this year, but if you’re both patient and lucky, you might see some falling stars and the occasional “fireball” every few minutes.

No worries about these meteors destroying the earth, though.  The dusty debris left in Temple-Tuttle’s trail is tiny, fluffy stuff; usually no bigger than a grain of sand.  However, if one of these grains gets pulled into the earth’s atmosphere, its brilliant destruction is what we call a “falling” star or a “shooting” star.  They travel around 45 miles per second (or 60+ kilometres per second, if you prefer), slam into the earth’s atmosphere, and burn up many miles above the earth’s surface.  Some hunks of space rock do reach the earth, usually splashing into the oceans and being lost forever, but the Leonids aren’t robust enough to do this.

If you’re interested in seeing what you can see of this year’s Leonids, here’s what to do.

1.)  Try, if possible, to find a place with dark skies.  If you’re looking at Leo from in or around Ft. Collins, you’ll be looking high up in the southern sky…and that means that the lights from Denver south of town will wash out much of the darkness.  Even so, Leo is easy to spot from Ft. Collins.

2.)  Dress warmly.  Stargazing is the coldest pastime going, even colder than ice fishing.

3.)  Bring a chair, preferably one that reclines.  You won’t need equipment like telescopes, binoculars, or anything of that sort for meteor watching, though equipment like a thermos bottle of coffee or cocoa might be welcome.

4.)  Find Leo, position your chair (as time passes, you might want sometimes to shift your chair’s position as the earth rotates), get comfortable, and pick out a region of the sky just slightly to the back (east) of the aforementioned “Sickle.”

5.)  Enjoy – I hope!

Images: Isle of Sky Astronomy, Night Sky Hunter, European Space Agency, Armagh Observatory, Lowell Observatory

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1 Response to “The Leonid meteor shower”



  1. 1 Leonid Meteor Shower « More to Explore Trackback on November 16, 2010 at 5:08 pm
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