The European Space Agency’s Planck space telescope has beamed back its first, much-anticipated image: a map of the entire sky, composed of microwave light. That bright line in the center of the image is our own Milky Way galaxy, and the lights surrounding it represent not stars but the vast clouds of energies between them. The most exciting part for scientists might be those mottled areas at the top and bottom of the image.
That’s the oldest light in outer space—the cosmic microwave background radiation left behind by the Big Bang. Scientists hope studying it gives them new insight into the formation of the universe, Space.com reports. “ This is the moment that Planck was conceived for,” says one ESA official. “We are opening the door to an Eldorado where scientists can seek the nuggets that will lead to deeper understanding of how our universe came to be.”