In the beginning, the universe was dark. The Big Bang had electrified the cosmos into existence, and the new landscape buzzed with particles, chaotic and hot, before cooling off into a calm expanse of hydrogen and helium. Then something began to happen in the fog. Gravity drove pockets of gas to collapse in on themselves and ignite, creating the first stars. The radiant orbs began to cluster, forming the first galaxies: messy, misshapen things, not as polished as our Milky Way today, with its elegant spirals. But the young galaxies cast their sparkle into the darkness, illuminating the universe. They must have been beautiful.
Astronomers have studied this early epoch with telescopes on the ground and in space. They have detected some ancient galaxies, capturing them as they appeared billions of years ago, when the photons peeled off the surfaces of their stars and wafted across the universe. Still, there are whole chapters missing. We don’t really know, beyond those broad outlines, how or when the very first stars and galaxies came to be. Scientists have done what they can, stretching existing telescopes to their limits and filling in the gaps with theoretical models. But they know that there’s more primordial light out there, streaked with answers to some of humanity’s most existential questions. They just need a new kind of instrument to help them look even deeper.
That instrument is almost ready. The James Webb Space Telescope is currently sitting on top of a rocket in South America, surrounded by technicians obsessively checking every bit of it. Launch for the $10 billion observatory is currently scheduled for December 24, Christmas Eve. Webb, the product of a collaboration between three space agencies, is 100 times more powerful than its predecessor, the Hubble Space Telescope. While Hubble’s “deep field,” the famous shot featuring thousands of galaxies, could fit on a standard sheet of paper, Webb’s equivalent would be so expansive, one astronomer told me, that it would need to be printed on wallpaper. This time, the shot would reveal 1 million galaxies, including some of the earliest. [Continue reading…]