Meteor showers come around quite often, but most of the time we don't see them. That's because we both aren't very aware of them and because light pollution can ruin their beauty. Depending on your location with respect to both latitude and longitude, there are many different showers that occur every year with some variance. If it seems strange or concerning that Earth's atmosphere frequently and consistently becomes littered with meteors, don't fear: meteor showers almost never result in debris hitting the planet's surface.
A meteor shower occurs when Earth passes through the tail of a comet. Comets orbit the Sun just like we do, but generally have oval-like orbits. As a comet passes nearer to the Sun, some of its icy surface melts off, resulting in the release of a bunch of dust and rock particles. As Earth makes its own orbit, it often runs straight into these particles, producing a meteor shower.
Most meteors in a shower are actually meteoroids, which means they average about the size of a pebble. They assume the name "meteor" when they enter the Earth's atmosphere. So when you're seeing a "shooting star" or a series of them in a meteor shower, you're actually witnessing the glowing hot air a meteoroid produces as it streaks into the atmosphere.
Now that you can rest assured that meteors won't crash into you if you decide to go check them out, here are seven major meteor showers to mark on your calendar:
This shower appears somewhere in the first week of January and is best viewed in the Northern Hemisphere. The maximum activity last for only about six hours and the weather can be rough in January, so although this shower can be rather strong, it often falls a bit short.
Appearing in mid-to-late April, the Lyrids are strongest in the Northern Hemisphere, but can also be viewed at a lower rate in the southern Hemisphere.
3. Eta Aquarids
The Eta Aquarids are very strong when seen from the southern tropics, lasting for a full month from mid-April to mid-May and peaking somewhere around May 6 or 7 depending on the year. Activity is usually quite high for a week centered on that peak, even viewable to a lesser extent in the Northern Hemisphere just before dawn.
This is often considered the most popular meteor shower because it usually peaks near mid-August during warm weather. The meteors contained in it are called Perseids because the place in the sky from which they seem to originate is located near the prominent constellation of Perseus when at maximum activity.
The Orionids are usually a little less intense than the Perseids, but have been known to reach those heights of activity (50–75 streaks per hour). They're easily seen in both hemispheres and the best time to watch is just before dawn during the peak sometime in late October.
Peaking in mid-November, the Leonids have produced some amazing showers, most recently in 2001. This is due to exceptionally dense clouds of debris that the comet 55P/Tempel-Tuttle gives off every so often. Unfortunately, the next such occurrence isn't until 2099, but you can still view some shooting stars at a rate of about 15 per hour during the peak.
The Geminids are usually the strongest meteor shower of the year and peak somewhere around the second week of December. Best seen in the Northern Hemisphere, they are the only major shower that has solid activity before midnight.
(H/T: American Meteor Society)
Cover image: Flickr