This article will explain the differences between a meteoroid, meteor and meteorite. It will also provide details on some of the 10 biggest meteor showers of the year.
Meteoroids are pieces of rock or iron debris which travel around the Sun in our solar system. Most are broken off particles from asteroids and range in size from small grains to the size of a golf ball. However, meteoroids also come from a variety of other sources, including comets, the Moon and even the planet Mars.
As the Earth orbits around the Sun, it regularly passes through clouds of these meteoroids left behind by comets (rocks and ice) or asteroids (rocky object sometimes called minor planets or planetoids). These particles then evaporate high in the Earth’s atmosphere creating glowing streaks of light known as meteors or shooting stars.
On average, we can see a meteor once every 15 minutes in the night sky but when we pass through a particularly concentrated area in space, such as a comet’s tail, we witness an unforgettable cosmic show known as a meteor shower. During a meteor shower more than 20 meteors can be seen each hour in Earth’s atmosphere. But when this number increases to more than 1,000 meteors per hour the phenomena is known as a meteor storm.
Annual Meteor Showers
Since Earth’s orbit remains virtually the same each year, these night sky spectacles are predictable and are usually named after the constellation from where they appear to radiate. Among the most prolific meteor showers of of the year are the following:
Quadrantids: Caused by minor planet 2003 EH1 and named from an obsolete constellation called Quadrans Muralis, that is now part of Boötes. This meteor shower peaks on January 3 when up to 60 meteors per hour can be seen.
Lyrids: Caused by comet C/1861 G1 Thatcher and peaking around April 22 with up to 20 meteors per hour.
Eta Aquarids: Caused by Halley’s Comet and peaking on May 5 with up to 60 meteors per hour.
Perseids: Caused by comet Swift-Tuttle and peaking around August 12 with over 60 meteors per hour.
Orionids: Caused by Halley’s comet and peaking around October 21 with around 70 meteors per hour.
Leonids: Caused by Tempel-Tuttle comet and peaking around November 17/18 with up to 30 meteors every hour.
Geminids: Caused by a minor planet called 3200 Phaethon and peaking around December 13/14, with around 70 multi-coloured meteors per hour.
A meteor that then reaches the Earth’s surface without being vaporized is known as a meteorite. These are classified as either stony, iron or stony-iron. Freshly fallen meteorites are often dark brown or black in color and covered with a thin coating of glass called the fusion crust. This crust is formed when meteors are superheated falling through Earth’s atmosphere. However, after laying in the ground for a while and being attacked by the Earth’s elements, this fusion crust often crumbles away.