Submission + - Ancient Supernova Explosion Glimpsed Anew (wired.com)
palegray.net writes: "Astronomers are observing a supernova exactly as it appeared in 1572, a peculiar ability made possible by the slowing of light by dust particles on its way to Earth. Radio waves from the event were first detected in 1952, with "light echoes" being used to observe it as it appeared hundreds of years ago. From the article: "These rays of light coming from the supernova are only just reaching Earth now because they took the long way home, bouncing off dust particles in the interstellar medium on their way.""