Earth is set to experience one of its closest near misses for a long time in November 2011, when asteroid 2005 YU55 passes within 0.85 lunar distances of our planet.
The asteroid has a diameter of around 400m and is being officially classified as a ‘potential threat’. It will definitely miss the planet, and will also miss the moon, although it will pass within 150,000 miles of the latter.
The size of 2005 YU55 makes it particularly dangerous. If it hit a populated area on Earth, the resulting explosion would have the force of several nuclear bombs. And if it hit the moon, it could push our satellite off orbit with potentially disastrous results for the tides on Earth. In other words, we should be very glad that 2005 YU55 is going to miss us, and we should be more prepared for the inevitable time when a similar asteroid isn’t so accommodating.