Earth Encounters Comet Bits – the Leonids Meteor Shower – on 17/18 November
Comets have been found to contain a wide collection of organic materials as well as water. Given the intense bombardment of the inner solar system shortly after Earth and Mars formed it is thought that many volatile components – and perhaps organic compounds – may have arrived via impacts by cometary bodies.
As such, the characterization of comets – or in this case, pieces of comets – is crucial in developing an understanding of the role of comets in seeding planets with the raw materials from which life might arise.
The annual Leonids meteor shower is a perfect opportunity to understand the composition of comets. The Leonids result when the Earth passes through a trail of debris left by comet 55P/Tempel-Tuttle as it orbits the sun.
According to NASA ARC: “Every year the Earth travels through the debris of many comets. That debris has moved far enough away from the comet orbit to collide with the Earth. The resulting meteor showers are referred to as “the annual meteor streams”. In most years, the Leonids are a rather insignificant annual meteor stream. Rates peak at 13 per hour on November 17, 2000. The main activity is between November 13 and 20, but Leonids occur annually at a rate larger than 1 per hour in the period between October 31 and November 30 (in good dark skies early in the morning).”
Related Links and Background Information
“On Nov. 17 and 18, 2000, space forecasters expect a series of Leonid meteor outbursts with flurries possibly exceeding 100 shooting stars per hour. Observers in Europe, Africa, and the eastern half of the United States and Canada are generally favored for best viewing, but the Leonids are notoriously unpredictable. Everyone, everywhere should remain alert for meteors during the hours before local dawn next Friday and Saturday.”
“The Moon is heading for a close encounter with a Leonid debris stream on Nov.
17, 2000.”
This is the main website for NASA Ames Research Center’s ongoing campaign to use ground based and airborne instrumentation to examine the Lenoids.
“Calculate your expected meteor shower activity from your location on Earth under a range of observing conditions in November of 2000.”
“Six teams of scientists led by NASA’s Marshall Space Flight Center in Huntsville, Ala., will monitor the annual Leonids meteor shower this month when the phenomenon
is brightest over the North American continent.
Part of the monitoring activities will include the launch of a weather balloon carrying video and audio equipment which will allow scientists and the public to actually hear
what a meteor sounds like as it crashes into Earth’s atmosphere.”
“The Leonid Multi-Instrument Aircraft Campaign is NASA’s first astrobiology mission. Its mission is to study the link between the abundant organic matter found in comets and interstellar matter in space, and the terrestrial environment that generated life on our planet.
“Last year’s Leonid meteor storm yielded rich research results for NASA astrobiologists,” said Dr. Peter Jenniskens, a NASA astronomer based at Ames Research Center
and principal investigator for the airborne research mission. “Findings to date indicate that the chemical precursors to life — found in comet dust — may well have survived
a plunge into early Earth’s atmosphere.”
Jenniskens and his international cadre of researchers think that much of the organic matter in comet dust somehow survived the rapid heating of Earth’s atmospheric entry.
“Organic molecules in the meteoroid didn’t seem to burn up in the atmosphere,” he explained. They may have cooled rapidly before breaking apart, he concluded.”
