Asteroids, Meteors and Comets are cosmic visitors from the far reaches of space. Commonly grouped together as they are basically the same thing - rock and ice from deep space.
Despite being grouped together they are very different and are easily distinguishable from each other.
There is also an asteroid belt closer to Earth, a group called Near-Earth Asteroids. They are much closer to the Earth and occasionally may cross our orbit.
There are different types of asteroid. Pictured below is asteroid Itokawa which is believed to be a 'rubble pile' formed from fragments that have cohered over time. Other asteroids such as Gaspra are monolithic (one massive chunk of rock). One asteroid called Ida even has a smaller satellite orbiting it (Dactyl)
Meteors are probably better known as "shooting stars". They are small pieces of space debris and dust, or fragments from comets. They range in size from a grain of sand to about the size of a cricket ball. When they hit the Earth's atmosphere they heat up and glow leaving a streak across the sky. Some of the larger meteors explode or burst into flames and become a fireball as they travel through the atmosphere.
A meteor shower occurs when the Earth passes through the trail of a comet which left a lot of dust behind. These showers can be predicted and come every year or so as the Earth passes once more through the trail. Meteor showers are named after the constellation that the meteors appear to be coming from (radiate), for example Orionids from Orion, Leonids from Leo and so on.
A meteoroid is the name given to the space dust and small objects as they exist in space. Once they enter the Earths atmosphere they become meteors. If the meteor is sufficiently large, or made of a strong material, it may impact the surface and is called a meteorite.
Scientists estimate that 1,000 tons to more than 10,000 tons of meteoritic material falls on the Earth each day. However, most of this material is very tiny - in the form of micrometeoroids or dust-like grains a few micrometers in size.
As the comet moves closer to the Sun Solar energy causes the nucleus to heat up, the ice vaporises, taking dust and small pieces of debris with it. As the comet is moving through space, this dusty vapour forms the characteristic tail. The name "comet" comes from the Greek meaning "long-haired" because of their tails. When the Earth passes through the debris left behind the comet we see a meteor shower.
My website and its content are free to use without the clutter of adverts, tracking cookies, marketing messages or anything else like that. If you enjoyed reading this article, or it helped you in some way, all I ask in return is you leave a comment below or share this page with your friends. Thank you.