What are the chances of Near Earth Objects (NEOs) hitting our Planet Earth?
We have heard of various other objects in space - asteroids, comets, meteors, meteorites etc. All of them have the potential to strike earth which can cause serious damage and maybe even wipe out humanity but the possibility of that happening is really low, as said by scientists. Thousands of asteroids of diameter up to 1 metre hits earth’s atmosphere every year, most of which gets burned up while entering the atmosphere and the rest sometimes make headlines. The damage-causing comets, AKA Centaurs - NEOs (Near Earth Objects) from Mars and beyond- have a chance of hitting earth once about every 40,000 to 100,000 years.
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| Comet |
Our planet has a long history of being hits by NEOs over the past billion years, the most notable of which is the Chicxulub crater-causing asteroid killing all dinosaurs and warming up the earth by 5 degree for the next 100,000 years. This had a diameter of about 10 kilometres and has caused the largest impact on earth in the past 500 million years. Another famous crater on earth is the Ries Crater in Bavaria- a lush green basin with a diameter of about 25 kilometres- within which nestles Nordlingen.
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| The City of Nordlingen - Bavaria |
This crater is the result of an asteroid or a comet with diameter 1500 metre hitting Earth some 15 million years ago. Damage as serious as this happens once every million years or so. Dr. David Morrison of NASA Ames Research Centre estimates that there exist only 2,100 asteroids larger than 1 kilometre and about 320,000 larger than 100 metres. The asteroids causing the Tunguska event and the Arizona Meteor Crater were roughly around the size of 100 metres. However, if one of these larger NEOs hit earth in a densely populated area, the damages would be catastrophic but it
still would not endanger humanity.
To sum up, asteroids and comets are common when it comes to them entering our atmosphere. But what matters is the size. And any NEO colliding with Earth that can cause enough damage to it has a probability of about 0.1%. Earth is safe, for this century at least and with it, so are we.
Post Written By - Bahana Saikia
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