August 13, 2010 > 'The Sky is falling'
'The Sky is falling'
By William Marshak
Chicken Little might have been watching the Perseid meteor shower when he uttered this alarming pronouncement. Those who leave city lights behind can watch a spectacular sky show tonight. Every August, pieces of sky do fall as our planet travels through the debris (ice and dust) trail of the Swift-Tuttle comet. Those removed from strong light sources in urban and suburban settings can easily see a myriad of "shooting stars" as the dust, traveling at a great rate of speed, burns from the heat of friction with the Earth's atmosphere.
The best seats for this year's show have been available in the late-night hours beginning Wednesday through tonight's predawn hours. Up to 60 shooting stars will make their appearance every hour. This year, light reflected from the moon will have little impact on viewing since it was a "new moon" on August 9. Called "meteoroids" while in space, these typically small particles, usually the size of a grain of sand, rarely survive to hit the earth's surface. However, it a larger rock does, its title changes to "meteorite." The debris field of Comet Swift-Tuttle comes in contact with the earth's atmosphere in August of every year. Some years are better for viewing the result than others. This year promises to be spectacular.
Sometimes just a point of light that quickly fades, meteors can put on a grand show under the proper conditions. A fireball is the result of air compression and resulting heat as a particle pushes against the atmosphere. The resulting temperature of 3,000 degrees F can shatter larger, marble-sized - or larger - rocks, causing an explosion, a bright flash and sonic boom. The pre-dawn hours are usually best for viewing these fireworks.
Comet Swift-Tuttle is rarely seen unaided from Earth. In 1992, binoculars were necessary to catch a glimpse of it. Previously, it was seen by American astronomers Lewis Swift and Horace Tuttle in 1862. Although named for the two astronomers, reported sightings which coincide with the comet's orbit have been noted over 2,000 years ago. The name Perseid comes from the constellation Perseus. Although untrue, paths of the shooting stars make it seem that they originate from this constellation.
The appearance of the meteor cloud and resulting "shower" is also knows as "The Tears of St. Lawrence" in honor of a martyred Christian deacon, Laurentius. In 258 AD, he was tortured by the Romans and the commemoration of his sacrifice in early August is often accompanied by a sky filled with Perseid meteors.
In order to enjoy the show, experts caution that a relaxed and unaided view of the sky helps to spot movement. A lawn chair or a comfortable sleeping bag and blankets can make the night hours pleasant. Avoid glancing at lights while waiting since this can hinder night vision. Remember to bring plenty of wishes for there will be sky full of candles tonight!
For the adventurous who want a total Perseid experience, East Bay Regional Parks is offering a campout in the Sunol Regional Wilderness to view the Perseid Meteor Shower far from the urban and suburban glare. A 1.5 mile hike beginning at 5:30 p.m. will end at a camp to enjoy good food, camaraderie and an exciting night of meteor viewing. Contact (510) 544-2558 or visit www.ebparks.org for more information about #24754. Food is provided and gear will be transported by park personnel.
For those betting on a long lifespan, Swift-Tuttle is due to return as a visible object in 2126. However, for most of us, it is best to enjoy the show now. Even Venus, Mars and Saturn are cooperating as an opening act with bright appearances in the early evening.