Comets & Asteroids Shooting stars Meteorites Comets Asteroids Shooting stars Shooting Stars: At night, when looking at the clear sky, one may see streaks of light shooting from one side of the vision to the other at an accelerated rate. These are called shooting stars. Shootings stars are in fact dust particles which collide with our atmosphere at rapid speeds and the resulting friction causes the dust to burn up. Shooting stars may be seen on any clear night but is best observed during  a meteor showers. These dust particles helps Earth gain around 550 tonnes of weight every day. Meteorites Meteorites are chunks of space debris that hit the Earth. So far, no humans have been known to have been killed by meteorites though astronomers believe that a meteorite caused the mass extinction of dinosaur 65 million years ago when it  hit Central America, the meteorite is believed to have measured some 10 km in width. Comets Comets are essentially chunks of ice characterised by their tail of gas and dust which erupts from them as they are nearing the sun. Their tails always points away from the sun, no matter what distance awau from the sun it flies. One of the most famous comets is the Halley’s comet (first recorded by the Chinese is 240BC) which in 1986, a probe called Giotto flew into and took photos of its 16km long nucleus. Halley’s comet flies past earth every 76 years. Asteroids Asteroids are giant boulders floating around in space, most of which are confined within its elliptical orbit between Mars and Jupiter, collectively known as the ‘asteroid belt'. About 200 asteroids with diameters more than 100km and thousands with smaller diameters exist. Many scientists believe that asteroids are the shattered remnants of planets which increased in numbers as the asteroids smashed into each other and shattered themselves even more. In the even that an asteroid such as ‘Ida' (52km long) smashed into the Earth, there would be mass extinctions which would leave only bacteria alive, waves of fire would engulf the terrain destroying everything in its path including cities and forests, there would be tidal waves, earthquakes and massive floods of lava. The dust kicked up by all of the commotion would blot out the sunlight for decades. Fortunately Ida is in the asteroid belt 290 million km away from us, although there are many more large asteroids at closer to us.