Meteors (Article 69)
A meteor is commonly referred to as a shooting star or falling star. Anyone lucky enough to see one cannot but be amazed by the beauty of a celestial body soaring across the sky. Few realise what they have witnessed. In times gone by many myths and legends have been fashioned to try to explain this glorious nocturnal spectacle.
A meteor is actually the visible path of a meteoroid, which is a small bit of debris travelling through the solar system that enters the Earth’s atmosphere. It heats up rapidly due to what is known as ram pressure and begins to vaporise. During this process it leaves a gas trail behind it that becomes ionized and glows. It is this trail of glowing gas that we recognise and gives the meteor its more colloquial name of “shooting star”. If the meteor is large enough, survives the entry into our atmosphere and strikes the earth it is referred to as a meteorite! It is a lucky person who owns a “space rock”! A meteor striking the Earth or other objects may produce an impact crater; luckily Earth has been spared any major impacts in recent times but a quick look at a full moon demonstrates the potential damage!
A single meteor is an impressive sight but a meteor shower is breath-taking This is where a large number of meteors can be seen in a very short space of time. This results from a comet swinging by the Sun leaving behind great amounts of tiny particles in its wake. Earth will move through this stream of particles and we see a meteor shower as these particles pummel our atmosphere. The Earth can spend a few days passing through this stream allowing for multiple chances to view the shower.
Meteor showers are almost always named after the constellation from which they appear to originate. The most visible shower is the Perseids appearing to radiate from the constellation Pereus peaking around August 12th every year. Obviously these stunning events are best viewed away from light pollution.
Galway Astronomy Club host a one day Astronomy Festival on 27 Jan in the Westwood House Hotel in Galway city. Tickets at the door from 9 a.m. or call 0868434003. Eminent speakers from the U.K. and NUI Galway will cover such topics as Space Weather, Adaptive Optics, Brown Dwarf Stars and The Origins of Life on Earth plus a chance to visit NUI’s Galway Observatory housing Ireland’s best optical and radio telescope facilities. Clear Skies!
20-01-2007 Meteors (Article 69)
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