INTRODUCING DIDYMOS

The Didymos asteroid was discovered by the Spacewatch Project at Kitt Peak National Observatory in 1996, although it was only later that radar images indicated it was actually a binary system. It’s now known that Didymos itself is around 800 metres in size, while its smaller companion Dimorphos is just 160 metres across. This kind of binary asteroid is ideal for a Dart-type test because it’s much easier to detect small changes in its orbit than it would be with a lone asteroid. As for what those changes will be, only a practical test can tell us, since they depend to a large extent on the unknown interior structure of the asteroid.