Will the 2011 Leonid Meteor Shower give the exciting celestial show it usually does every November or will a bright Moon outshine the shower? Expert sky-watchers say that the Moon–almost in its last quarter phase during this year’s shower time–will be shining near the Leonids’ radiant point in Constellation Leo and therefore mute the Leonids with its neighboring brightness. However, die-hard sky watchers may still want to watch–and listen.
When to Watch the Leonids Shower. The Leonids will stream from their radiant point around November 17 to 18. Early-bird meteors may be seen as soon as November 10 while stragglers will finish last by November 20. For the Lower forty-eight States, the best viewing times for the shower might be on the midnight of November 17’s Thursday and into the small hours of Friday. However, the Leonids can have erratic peak times.
Although the meteors will be visible in any direction, look to the eastern sky–toward Constellation Leo from which the meteors seem to fall. (See an image of Leo here). Also watch the Moon for possible flashes from the impact of larger Leonids–in this case, a telescope, even an amateur one, might be necessary.
Where to Watch the Leonids. The best place for watching any meteor shower is anywhere away from the glare of city lights–try a public park or make an excursion to the countryside. In a warm clime, wear the usual summer clothes and bug spray. In a cold climate, bundle up and bring blankets. In either case, get out the deck chairs and get comfortable. Neither a telescope nor binoculars are needed. Just let your eyes adjust to the dark sky and start watching. When perusing a sky chart, use a flashlight with a red filter, which will allow your sight to stay attuned to the night sky.
How to Listen to the Leonids. The Leonid meteors leave a trail of ionized gas that can be heard. To listen to the Leonids Shower in November 2011, visit the Spaceweather site and then click on ‘Listen’. In fact, visit this site anytime to hear live Meteor Radio Echoes as the Air Force Space Surveillance Radar constantly scans the skies above Texas. To assemble your own listening setup, read the ‘Do It Yourself’ section of ‘How to Hear the Leonid Meteor Shower’ (a 2006 article).
The Leonids Peak Years. A peak year for the Leonids cycles every thirty-three years. The most recent peak year for the Leonids was 2001; the next will be 2034. During a peak year, the Leonids create a frenzied storm, raining meteors up to 300 per hour (ph). Yet even during non-peak years, the Leonids generate a light phenomenon worthy of watching as they fall at an average rate of forty meteors ph–except for when cosmic conditions make visibility poor.
What Determines the Leonids Visibility? Apart from how bright or dim the Moon, the location of the radiant point determines the meteors’ visibility. If the radiant point is below the Earth’s horizon, then few if any meteors will show through Earth’s atmosphere. The radiant point is highest in the hour before dawn–a good time to watch.
What Causes the Leonids Shower? Their parent body–the Comet Tempel-Tuttle–creates the Leonids Shower by shedding streams of dust and meteoroids, seen as shooting stars. First discovered by Ernst Tempel in 1865 and then by Horace Parnell Tuttle in 1866, Comet Tempel-Tuttle is a periodic comet that runs through the inner solar system every thirty-three years as it orbits Earth’s sun and then returns to the outer solar system–hence the Leonids 33-year cycle. Tempel-Tuttle may be 4.6 billion years old.
What Is a Shooting Star? A shooting star is the detectable path of a meteoroid as it enters Earth’s atmosphere. The meteoroid then becomes a meteor. If it is very dense–and perhaps large–it can survive a collision with Earth. The survivor is called a meteorite.
The Leonid meteors are tiny, ranging in size from a sand speck to a large garden pea. They shoot into Earth’s upper atmosphere at a blinding speed of 160,000 mph that causes the air ahead of them to compress and heat up to about 3000 degrees Fahrenheit. Appearing as shooting stars, they typically burn up or vaporize–brightly–while about sixty miles above the Earth.
In outer space, the rare larger Leonids can damage spacecraft–about 650 satellites are orbiting the Earth. To learn what types of damage they can do, visit Aerospace, Center for Orbital and Reentry Debris Studies.
Do Leonids Land on the Moon? Since the Moon passes through the same vicinity of space as Earth, it also passes through the Leonids Shower. Because the Moon has no appreciable atmosphere that would cause the Leonid meteoroids to combust and burn up before hitting its surface–as happens in Earth’s atmosphere–the Leonids explode against the Moon’s surface, causing flashes of light, which if made by a larger Leonid meteoroid might be seen at least through an amateur telescope if not by the human eye.
More About the Leonid Comet Streams. On every periodic journey through the solar system, Comet Tempel-Tuttle sheds a new stream of icy meteoroids or particles. The new stream mingles with existing streams. The Earth moves through these diverse streams in varying parts, which is why the Leonids’ celestial outburst always varies in intensity. The meteor shower of 1833 was so bright that it woke people from their beds. Some nineteenth-century watchers thought the world was ending. For an amazing photograph of Leonids over Norway, look at Spaceweather’s Meteors Gallery.
All meteors, including the little Leonids, are great sources for studying the beginning of the world–the beginning of life. They contain the chemical precursors to biological activity. As electronic musician Moby sings, “We are all made of stars.”
Sources: Leonid Meteor Shower; Meteor Shower; Radiant; Leonid Facts.