Glimpsing the Universe's First Stars: Astronomical Archaeologists' Discovery.

Astronomers using the European Southern Observatory have observed clouds of gas in the early Universe that were predominantly hydrogen and helium but also contained other lighter elements, but very little iron. They concluded that they were seeing the chemical signature of the leftover debris of the very first stars to come into existence after the Big Bang. The researchers used quasars as cosmic spotlights to illuminate gas clouds and studied the light that passed through the clouds to determine which elements were present.