Saturday, August 7, 2010

Perseids Meteor Shower

Fire from the skies (in monsoon!!!!)
Perseids Meteor Shower
Night of August 12th, 2010

Seeing a shooting star in the sky makes one feel that a star has died, but is it really so. Death of a star results in one of the biggest celestial shows in the universe and definitely a shooting star is not that. The words “shooting star” it self is a misnomer. We all know that when a small particle of space dust enters earth atmosphere, it burns up while travelling towards Earth and result is a streak of light in the skies. It has nothing to with star death. Sometimes the particle is so big that part of it burns in the atmosphere and the rest falls on earth as it happened last few years in certain parts of India.

The show
Perseids can be seen from July 15th –August 25th. Most of these nights one can see few meteors from the shower. Night of August 12 is the peak of the Perseids meteor shower. timing of the mean or ‘traditional’ broad maximum will vary between August 12, 18h30m UT to August 13, 07h00m UT, while the shorter, enhanced will be between August 12, 09h30m to August 13, 13h30m UT. When Perseus rises in the northeast. This is the time to look for Perseid Earthgrazers--meteors that approach from the horizon and skim the atmosphere overhead like a stone skipping the surface of a pond. Earthgrazers are long, slow and colourful; they are among the most beautiful of meteors. An hour of watching may show only a few of these--"at most"--but seeing even one makes the long night worthwhile. The thin, crescent moon will be out of the way early, setting the stage for a potentially spectacular show. For best viewing, look to the northeast after midnight. Other things which will spoil the show will be monsoon clouds.

How to observe the meteor shower?
Don’t expect hundreds of meteors in the skies at one time. Perseids meteor shower usually have ZHR of around 100-120 meteors. Now what is this term ZHR? Official figures for meteor numbers are given as the ZHR or Zenithal Hourly Rate. This is the number of meteors you could expect to see given perfect conditions if the radiant (the point from where all the meteors seem to be coming) was directly overhead - i.e. at the zenith. Obviously, if the radiant is on the horizon, you can't see half the sky around the radiant, so you will only see half the number of meteors. Again, if half the sky is cloudy, you will only see half the number of meteors. Hence, for a ZHR of 110 (about what you can expect for the Perseids shower), you might only see two-thirds or half because the radiant isn't directly above your head. So expect to see around a meteor per 2 minutes !!

The first and last rule of meteor observing is look up. If you do not look up, you will not see any meteors, because by the time someone else has seen it, it will be gone before you look in that direction. Rules for meteor observing are generally the same as for all astronomy observations. The exception to that rule is that you should be looking up at all times. You can employ an easy chair for this purpose, but the best way is to get a sleeping bag and find a dry, comfortable spot to lie down on.

For observation make sure that you have the widest area of sky visible possible. Try to get away from light pollution. If you can see the Milky Way, it will be dark enough to see meteors. Typically, meteors will be about the same brightness as Venus or Jupiter down to the brightness of medium-brightness stars).

Depending on your location and disposition, insect repellent like odomos gel might be advisable as well. On the whole, just use common sense and try to enjoy yourself. Meteors can provide some of the more spectacular sights in the sky, so stop reading about it and get out there!

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