[G]alaxies around us are hiding about a third more atomic hydrogen gas than previously calculated. . . the gas is distributed very differently from how it was in the past, with much less in the galaxies' outer suburbs than billions of years ago. "This means that it's much harder for galaxies to pull the gas in and form new stars," Dr Braun said. "It's why stars are forming 20 times more slowly now than in the past." . . . "Even though there's more atomic hydrogen than we thought, it's not a big enough percentage to solve the Dark Matter problem. If what we are missing had the weight of a large kangaroo, what we have found would have the weight of a small echidna," Dr Braun said.From here.