3 days' notice
Later today, asteroid 2010 TD54 will pass within 45 000 km of the Earth. For those keeping track at home, this is about 1/9 of the distance from the earth to the moon. Notice the name of the asteroid - 2010 TD 54? That "2010" means it was spotted this year. On October 9th, in fact.
While it's good that this particular chunk of space rock (which is less than 10 metres across) will whiz by harmlessly, or at worst burn up in our atmosphere, I'd be MUCH happier knowing that we could get a bit more than 3 days' warning if something much bigger came along.
While it's good that this particular chunk of space rock (which is less than 10 metres across) will whiz by harmlessly, or at worst burn up in our atmosphere, I'd be MUCH happier knowing that we could get a bit more than 3 days' warning if something much bigger came along.