Astronomers Detect More Missing Matter

Forget about dark matter, the mysterious invisible stuff that scientists say holds the galaxies together. The plain old ordinary matter that makes up stars, planets, and you and me presents puzzles of its own. The early universe contained up to 10 times more of it than would fit into all of today's galaxies, and no one knows where it all went. Now new data from the Hubble Space Telescope suggest that much of it may be hiding out in the open, in enormous clouds of ionized gas stretching between galaxies.