Week of November 12-18, 2017
Anyone who has ever gazed into a dark night sky for longer than just a few minutes has almost certainly seen a burst of light appearing out of nowhere, and disappearing just as quickly.
We call such startling phenomena romantic names like "falling star" or "shooting star," but a more accurate term is "meteor."
These are often tiny particles from space (meteoroids) that slam into our upper atmosphere at tens of thousands of miles per hour and glow brilliantly as they meet their fiery demise (meteors). Believe it or not, most are no larger than a grain of sand.
If a walnut-sized meteoroid were to encounter our atmosphere, it would outshine everything in the sky and even cast a shadow. These "fireballs" can fragment, explode or even leave lingering trails behind them. If such a body were large enough to survive its plunge through our atmosphere and crash to Earth, it would then have a new name: meteorite.
At times throughout the year, our planet encounters swarms of meteoroids left behind by ancient comets, and we on Earth experience a meteor shower. While we name these for the constellation from which its meteors appear to radiate, we can see meteors all around the sky.
Late this coming week, we will experience one of the year's major showers. And because it appears to originate among the stars of the constellation Leo (now appearing low in the east around 2 a.m. in all time zones), we know this display as the Leonid meteor shower.
The Leonids are best known for their 33-year peaks, when sky watchers report seeing hundreds, or even thousands, per hour. We expect nothing like this in 2017, of course, but the Leonids are still fascinating to watch. The 10 or 15 meteors that rip through our atmosphere every hour are very fast. Some can burst brightly in blue or green, and often leave a beautiful trail of smoky material behind.
Astronomers figure this year's Leonid shower will officially peak around 1 p.m. EST (10 a.m. PST) on Nov. 17. While it will be daylight at that time for North Americans, we will actually see the Leonids during the pre-dawn hours of Nov. 17 and, possibly, Nov. 18.
Closer to dawn that morning, you may spot the extremely thin crescent moon very low in the east-southeastern sky, with the bright planets Venus and Jupiter not far above the horizon.
Whether or not the Leonids will produce a nice display this year is anyone's guess; the only way to find out is to go out and watch. The trick is to get far away from city lights, dress warm, lie on a sleeping bag or lawn chair, and scan the entire sky with your eyes.
To view the meteor shower, you need no special equipment; in fact, your eyes alone are your best tools. But when one of the great Leonid fireballs bursts across the heavens and leaves behind a lingering trail, you can use binoculars to watch it twist and turn for several minutes in upper-atmospheric air currents.
To learn more about this shower and the predictions scientists have made, visit earthsky.org/?p=29831.
Visit Dennis Mammana at www.dennismammana.com. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.
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