Comet Halley dust rains down upon Earth in the early mornings of October

 

Periodic trips through the inner solar system has left a little dust behind. NASA photo.

Modern star gazers can take in a show that has been entertaining star gazers for thousands of years. The Orionid meteor shower peaks on the night of October 21, the Moon will also be in full phase on this night, and this light will drown out the light of all but the most energetic of meteorites. The Orionid meteor shower still occurs between October 2 to November 7, so patient star gazers will to stay up until the early morning hours in the middle of October, will still have a good chance of seeing a few meteorites.
 
 

Orionid meteorites are small dust grains thrown off by Comet 1P/Halley, during its many trips through the inner solar system. These dust grains are traveling at a speed generally in the area of 70 km/second, at this speed the surrounding air will glow with heat as a dust grain travels through Earth's atmosphere, and viewers will a brief flash as the meteorite vaporizes in the atmosphere. Astronomers estimate that about 25 million particles of comet dust enter the Earth's atmosphere worldwide on a daily basis, burning up as meteorites and adding hundreds of tons of comet dust. During a meteorite shower Earth is being bombarded by numerous grains of comet dust as the Earth travels through the orbit of a comet. Meteorite showers occur annually due to the fact that the Earth travels through the orbit of a comet at the same time each year. Typically viewers can see a few meteorites each hour on a clear night, but viewers can always be treated to an extra special show.

During a good performance viewers could see upwards of twenty meteorites per hour radiating from one direction in the sky generally, just as heavy rain or snow appears to radiate from one direction in front of a moving vehicle. The Earth is moving relative to the comet dust, as a result more comet dust will hit the Earth's atmosphere in the part facing in the direction of the Earth's movement, and viewers will get a better show in the pre-dawn sky, when part of their sky is facing in the direction of Earth's rotation.

The Orionids are comet dust left behind by Comet 1P/Halley. Nasa photo.
Star gazers can also view minor meteorite showers during October, the Draconid meteorite shower peaks October 8, just one day after a New Moon. Viewers may in fact have a better chance of viewing a meteorite on this night, due to the New Moon. Draconid meteorites only travel at 12 miles per second, rather slow for meteorites in fact, so you should be able to tell Draconid meteorites from typical sporadic meteorites. The Draconid meteorite shower is a relatively dull show, normally, but occasionally star gazers can get lucky and see a show reaching 10 to 30 meteorites per hour. Astronomers aren't predicting the Draconid meteorites will be putting on a show this year, but they've been wrong before.