Malin-1 is the first low surface brightness galaxy to be discovered and the largest spiral galaxy known; it lies about one billion light-years away in Coma Berenices. Despite its diameter of nearly 600,000 light-years and mass of over two trillion solar masses, its gas-rich disk is so faint that it was found only by accident in 1987 by American astronomers Christopher Impey and Gregory Bothun on photographic plates processed by the English-born astronomer and photographer (now based in Australia) David Malin (1941–).