What Are Asteroids?

First let us explain the only diffence between an asteroid and a meteroid: their sizes. Anything smaller than 1 mile across is considered a meteroid. Anything larger is considered an asteroid.

Asteroids are mini planets that orbit the Sun, mainly concentrated between Mars & Jupiter - known as the Asteroid Belt.

Scientists believe there are at least 40,000 asteroids in this area. The main ingredient in this flying debris of dust & rocks is 'irridium'. The largest asteroid in the belt is known as Series (600 miles wide) and then Vesta and Polis (350 miles wide)

Sky Gazing

Shooting stars (meteors) are best spotted when the Earth travels close to a swarm of meteroids in its path around the Sun. The most famous meteor shower is called Perseids. In North America, these are typically viewed best in August.

As a meteoroid travels close to Earth our atmosphere burns them up and they disappear. However, sometimes a large meteoriod does make it to Earth then it is called a meteorite. The largest one known to man, fell in prehistoric times in Namibia, Africa. It weighs more than 60 tonnes. It is still there.

Threats & Benefits

Some scientists believe that it was an asteroid that destroyed the dinosuar's reign on Earth, 65 million years ago. An average size meteoroid (300 yards across) could cause the equivalent damage of a large scale nuclear war, sending a murderous cloud around the Earth and cover us in complete darkness for a month.

This is no reason to fear a devasting hit by an asteroid. An asteroid of that size would only hit Earth every 10,000-15,000 years (statistically speaking). We are now working on predicting and tracking any perilously close asteroids. In the event that one came too close to the Earth we could attempt to deflect, destroy or pulverize the asteroid.

Asteroids and meteors are not necessarily a bad thing. Scientists are also working on how we could mine these floating hunks of rocks for valuable minerals such as nichel and iron. These 'rocks' could also be used as a stepping stone to living in space.

Above: Artist rendition of a "shooting star" passing thru the Earth's atmosphere. Courtesy NASA.

• Meteor Crater, Arizona, USA
• Wolf Creek, Australia
• Manicouagan, New Quebec, Canada
• Clearwater Lakes, Quebec, Canada