A very small asteroid named 2018 LA exploded in the sky above Botswana earlier this month. As the object wasn’t big enough, it didn’t create any real damage. However, since the space rock was spotted only a few hours before its explosion, it raised serious questions about the state of our asteroid defense system. If a much bigger object was to enter the Earth’s atmosphere, it could create damages on a global scale.
Our chances of spotting the danger from space
According to Lindley Johnson, NASA’s Planetary Defense Officer, relatively small asteroids are very difficult to spot. At the moment, the main instruments that NASA uses in order to patrol the night sky are ground telescopes. The scientist said that the chances of picking up an object approaching Earth from the night side are quite high, regardless of its size. However, our chances of spotting any space rock approaching Earth from the day side are very limited. Such object would be virtually invisible, due to the light of the Sun and the chances are that either we wouldn’t see it at all or we would spot it too late, with no time left for us to react.
NASA is actively trying to improve the detection and deflection of asteroids and the recently launched “National Near-Earth Object Preparedness Strategy and Action Plan” gives us hope that the Earth will be better protected, especially against smaller objects, which at the moment are incredibly hard to spot.
Catastrophic events in the past
Some 65 million years ago, an asteroid more than seven miles wide hit the Earth, which caused great environmental changes and the extinction of dinosaurs. However, the space-rock doesn’t necessarily have to be that big to create damage. We were able to see just that in 2013, when a 20 meters wide asteroid exploded above Chelyabinsk, which resulted in 400 injured people. The biggest asteroid that hit the Earth in the recorded history was up to 190 meters wide. The famous Tunguska event from 1908 created an explosion up to one thousand times more powerful than the atomic bomb that destroyed Hiroshima.