‘What emergency managers want to know is when, where and how an asteroid would impact, and the type and extent of damage that could occur,’ said Leviticus Lewis of the Response Operations Division for the Federal Emergency Management Agency (FEMA).
Last year Lindley said there was only a ‘limited’ chance of spotting asteroids coming from a certain direction in space.
It’s very easy to track large objects, but tinier ones can often appear on the horizon a short time before impact.
Nasa relies on using ground telescopes to look at the night sky.
This means that if asteroids approached from the ‘day side’ of Earth, it would be invisible because the sun’s light would stop us from seeing it.
‘If the object is coming into the inner solar system and approaching Earth from the night side… our chances are pretty good of picking up objects of almost any size as they come close to Earth,’ he said.
‘The smaller it is the closer it would have to come to earth for us to detect it.
‘But we have a vulnerability from the day side if asteroids have already had their closest approach to the sun, which is called their perihelium, then coming back out of the Solar System and approaching earth from the day side our capability to detect them ahead of time right now is very limited.’
The asteroid which killed the dinosaurs was believed to be more than seven miles wide, but space rocks don’t need to be this huge to cause some serious damage.
When a 20-metre-wide asteroid exploded in the skies over the Russian city of Chelyabinsk in 2013, the resulting ‘airburst’ caused by the detonating meteorite left about 400 people injured, with most wounds caused by shards of flying glass from windows smashed by the shockwave.
In 1908, 80 million trees were knocked down over an area of 800 square miles hidden deep in the Siberian forest when a meteor which was up to 190 metres wide crashed into Earth. If the object which caused this devastation had hit a populated area, it could have killed millions and razed a city to the ground.
The mysterious ‘Tunguska event’ was the largest asteroid impact in recorded history and caused an explosion 1,000 times more powerful than the bomb which destroyed Hiroshima.
There are not believed to be any asteroids currently on a collision course with Earth.
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