Near-Earth-Objects

Near-Earth-Objects (NEOs) are small objects in the solar system. They have struck Earth in the past and will definitely hit again, but are we in danger of Near-Earth-Objects?

The Earth has been hit by asteroids, comets and meteorites in the past. Scientists believe that when a large asteroid collided with Central America 65 million years ago

, the dinosaurs became extinct. The collision threw up water and rock which hid the Sun and covered the Earth in darkness for months. Dinosaurs could not survive in the cooler climate.

Of the Near-Earth-Objects, Most meteors are tiny and burn up in Earth's atmosphere. Even the ones that do get through and land as meteorites are mostly very small. The Earth's atmosphere protects us from all objects up to about 40 metres across. Asteroids pose a much bigger threat to Earth as they tend to be much larger objects.

If an asteroid with a diameter of more than two kilometres hit the Earth, it would cause a catastrophic planetary event. Many people would die as a result of the impact and of the Earth entering a long cold winter where most crops die. The good news is that an asteroid of this size only collides with Earth about once every 100 million years. The Spaceguard survey scans the skies looking for any dangerous NEOs. As yet, none that are on a collision course with Earth, have been discovered.

When a bigger object does head our way, we should have the advance warning and technology to deal with it.