Astronomers track asteroids heading for Earth in major breakthrough

manchestereveningnews.co.uk:

Astronomers from an elite university have found a way to spot tiny asteroids within the main asteroid belt — a rubble field between Mars and Jupiter where millions of asteroids orbit.

Until now, the smallest asteroids that scientists were able to discern there were about a kilometre wide, but the MIT team’s new approach, scientists can now spot asteroids in the main belt as small as 10 metres across.

The asteroid that extinguished the dinosaurs is estimated to have been about 10 kilometres across and asteroids of that size are predicted to hit Earth rarely, once every 100 million to 500 million years.

In contrast, much smaller asteroids, about the size of a bus, can strike Earth more frequently every few years. These “decametre” asteroids, measuring just tens of metres across, are more likely to escape the main asteroid belt and migrate in to become near-Earth objects.