What is a meteor shower?
A meteor shower happens when a comet orbits the Sun and it sheds a dusty and icy debris stream along its orbit path. If Earth happens to be travelling through this stream, this is when you’ll see a meteor shower.
The meteors can appear anywhere in the sky, but if you trace their path back up they appear to “rain” in from the same region of the sky.
Usually, these showers are named for the constellation that coincides with this region of the sky – this spot is called the “radiant”.
So for example the Leonid meteor shower has its radiant in the constellation Leo and the Perseid meteor shower is named because the meteors appear to fall from from a point in the Perseus constellation.
Meteor showers in 2021
|Name||Date of Peak||Activity Period|
|Quadrantids||Night of January 2/3||Dec 26-Jan 16|
|Lyrids||Night of April 21/22||Apr 15-Apr 29|
|Eta Aquarids||Night of May 4/5||Apr 15-May 27|
|Perseids||Night of August 11/12||Jul 14-Sep 1|
|Orionids||Night of October 21/22||Oct 02-Nov 07|
|Leonids||Nights of November 16/17||Nov 06-Nov 30|
|Geminids||Night of December 13||Nov 30-Dec 17|
|Ursids||Night of December 22||Dec 17-Dec 24|
What are shooting stars?
Both “shooting stars” and “falling stars” are terms used to describe meteors. The bright streaks of light across the night sky are caused by small pieces of interplanetary rock and debris – called meteoroids – which burn up under the intense friction of Earth’s atmosphere some 30 to 80 miles above the ground.
These meteoroids travel at tens of thousands of miles per hour and while most are completely burned up by the atmosphere, the 500 or so per year that do reach the ground are called meteorites.
When a meteor appears in the sky, it appears to “shoot” at great speed across the sky, with a brightness and intensity that you might think it’s a star rather than a falling piece of rock.
Famous meteor showers
There are plenty of famous meteor showers that are easy to observe. The Perseid meteor shower, for example, happen in mid-August when Earth moves through the debris stream of the comet Swift-Tuttle. This shower can be seen for most of the night.
The Leonid meteor shower is often a busy one with many thousands of meteors showing down from the Leo constellation. It happens in mid-November and the debris that rains down comes from Comet 55P/Tempel-Tuttle. The Leonid shower is best viewed from the North – where the constellation Leo rises.
In December, the Geminids meteor shower happens when Earth crosses stream from the asteroid 3200 Phaethon in what appears to be the direction of the Gemini constellation. Observers have commented that the meteors in this shower travel more slowly than other showers. This year (2014), they will be in view some time after midnight on the night of December 13.
In late April, the Lyrids shower will rise at around 3am and bring with it pieces from the comet C/1861 G1/Thatcher, radiating from the Lyra constellation. The peak of this shower is usually April 21/22 and every 60 years the shower becomes more intense.
Meteor shower facts
- The majority of meteor showers are caused when Earth moves through the debris stream of an orbiting comet.
- There are two known meteor showers that are the result of debris from asteroids rather than comets. The Quadrantids shower is believed to be a result of the debris from the minor planet 2003 EH1 and the Geminid meteor shower is from the debris of an asteroid called 3200 Phaethon.
- The Orionid Meteor shower which happens in late October each year is a result of dust and debris from the famous Comet 1P/Halley.
- A study by Nature in 1985 looked into how rare it was for a human to be struck by a meteorite. The study estimated that a meteorite would strike a person once every 180 years – an average of .0055 per year. Since there is only one confirmed case of this, Ann Hodges in 1954, this would suggest that another person won’t be struck until 2134.
- The earliest recorded Perseids meteor shower is found in Chinese annals from 36 AD.
- The best time to view a meteor shower is in the early hours of the morning with a dark night and a moonless sky. Some showers, like the Leonids, are best viewed in the North.
- Some meteor showers, such as the Alpha Monocerotids do not happen every year. But when they do they can be very impressive!