Whilst we are all aware of the risk of an asteroid strike on our planet, maybe we are not so aware of the number of strikes that already take place. The B612 Foundation has published a video and The Economist this week published a map showing asteroid strikes on The Earth over the last decade. Happily all of them resulted in aerial explosions but with surprising force. The data comes from the B612 foundation which is raising funds to launch a "Sentinel" IR satellite to detect small asteroids earlier and hopefully to guard against one of these explosions taking place over a city where the damage could be enormous.