BBCNEWS Breakfast November 23, 2021 06:55:00
Back to us. things are only 100 metres or about that size, where they start to get a bit danger, they are really faint. the way we spot them is we look at things that move or change in the sky night after night. these things hop along in front of them. night after night and thatis front of them. night after night and that is how we figure out their orbits and if they will ever be a danger to earth. we have found most of the big ones. anything around about 140 metres, round about the size they are testing this oneand, if they did impact on earth they could cause local disruption. if they landed...
Source: archive.org