Two days ago a very large asteroid came close to the Earth. It was more than two miles across and could have caused a colossal amount of damage if it had hit our planet. Thankfully the asteroid was only close in the astronomical sense – it was really over four million miles away, so there was no need to worry!
So what exactly are asteroids, where do they come from and what risk do they pose to life on our planet? Wonder no more – Education Quizzes has all the information you need in this list of asteroid facts:
- The first asteroid was discovered 1801. It was named Ceres after the Roman goddess of agriculture. It’s very large for an asteroid and has since been reclassified as a dwarf planet
- Asteroids are rocky objects which orbit the Sun, similar to planets. But asteroids are much, much smaller than planets. They vary in size from ten metres to hundreds of kilometres across
- Most asteroids can be found in the asteroid belt which lies between Mars and Jupiter. Their number is unknown but so far we’ve discovered 600,000 or so
- Asteroids are made from rocks, metals and organic compounds. We think that the planets were formed by asteroids colliding but those in the asteroid field never managed to take that step
- The organic compounds found in asteroids are thought by many to have been the original cause of life on Earth. An asteroid falling onto our planet probably brought the building blocks of DNA with it
- As well as bringing about life on Earth, asteroids have also destroyed it. An asteroid impact was responsible for the mass extinction event 66 million years ago which wiped out the dinosaurs
- Some asteroids (like the one which killed the dinosaurs) have left the asteroid belt and their orbits bring them closer to the Earth. We call these Apollo objects
- The last large asteroid to hit the Earth fell on Russia in 1908. It was only 150 metres wide but its impact destroyed thousands of square kilometres of the surrounding forest
So, should we be worried about an asteroid wiping out life on Earth? The answer is yes, and no. Asteroids large enough to cause a mass extinction fall, on average, every 60 or 70 million years. The last one was 66 million years ago so we are due to have one soon. But astronomers are always on the lookout for any potential threat – that’s how we knew about our latest visitor. If a large asteroid was on a collision course with our planet we would know well in advance and could take action to either destroy it or to alter its direction.
My advice – don’t worry. The best minds in the business are doing all the worrying so you don’t have to!