A supernova may have cleaned up our solar system

The blast from a supernova should be enough to clear almost all the dust from the solar system, and this may have last happened 3 million years ago. But like the dust on furniture, these fine particles will gradually be replenished.

Dust we see drifting through space consists of small grains, resulting from events such as asteroid collisions. The grains are typically less than a millimetre in size, going down to just nanometres across. About 70 per cent of the solar system’s dust is…