Whoosh!!

Several alarm stories in the press recently about asteroids passing dangerously close to Earth - only to be followed closely by official pronouncements saying that there's no danger, and plenty of room for the asteroid to pass us safely.  Lots of big numbers being bandied about which makes it difficult to get a handle on just how big these space distances are.  So how about this - we think of the moon as being pretty close to us, and yet there is actually room to fit all the planets (even including Pluto) between the earth and the moon with about 2,000 km to spare!  So it's pretty big out there.