Astronomers see ashes of the first starsDaniel Clery A team of astronomers has found a gas cloud that existed when the universe was 13% of its current age that appears to be made of the pristine gas produced in the big bang but with just a wisp of heavier elements: 1/3000 of the level in our solar system. This tiny impurity suggests that it contains the ashes of some of the very first generation of stars. These primordial stars, which first formed about 150 million years after the big bang, were unlike any today. With masses a hundred times or more that of our sun, they burned hot and fast, forging hydrogen into heavier elements in their fusion furnaces then spewing them out into space when they exploded at the end of their lives. Astronomers are just beginning to be able to study this process, which ultimately produced the materials for planets and life.
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