Powerful asteroids hitting the Earth's atmosphere caused 26 nuclear-scale explosions between 2000 and 2013, including one that was much stronger than the atom bomb that destroyed Hiroshima, a report has found.
The findings came from the Nuclear Test Ban Treaty Organisation, a global infrasound network that detects nuclear weapon detonations and recorded the impacts over 13 years.
Most explosions occurred too high in the atmosphere to cause any serious damage on Earth but "the only thing preventing a catastrophe from a ‘city-killer’-sized asteroid has been blind luck," said former astronaut Ed Lu as he revealed the data at the Museum of Flight in Seattle today, NBC reported.
Mr Lu added that while large asteroids have been detected, "less than 10,000 of the more than a million dangerous asteroids with the potential to destroy an entire major metropolitan area have been found."
The asteroid, given the not so catchy name of 2012 DA14, has been closely tracked since its discovery by a Spanish observatory a year ago. It is predicted to reach its nearest point to Earth at around 7.30pm tonight UK time.
Sky watchers have been told that given clear skies they should be able to track the rock climbing in the north-eastern sky from anywhere in the UK.
It will be possible to see it if you know where to look, but just waving your binoculars in the right general direction isn't going to work.
The asteroid will be a faint dot of light moving at a steady rate between the stars. It'll be thousands of times fainter than Jupiter and 250 times fainter than the stars of the Plough.
The trick will be to find the area in advance and wait for it to come through. You can use the star maps to find exactly the right part of the sky. If you hold your binoculars steady you will see this tiny point of light crawling across your field of view in about seven or eight minutes.
It's not easy, but you will have the thrill of knowing you are seeing a little object in space the size of an office block.
– Robin Scagell, vice-president of the Society for Popular Astronomy
There's speculation that the meteor could be linked to an asteroid that will pass through satellite space later today.
It is believed to be 50 metres wide and capable of wiping out a city the size of London and is expected to miss Earth by a distance of over 17,000 miles but is the closest ever predicted for an object of that size.
Astronomer Nigel Henbest told ITV News the asteroid is not linked to the Russian meteor: