Studying galaxies in the night sky is an exercise in time travel, since the light we are seeing represents how things looked in the past, sometimes even billions of years ago. So studying the very farthest galaxies from us can clue us in on what the early universe was like – and if two newly discovered galaxies are any indication, the cosmic dawn could have been a lot more lively than anyone realized.
The new galaxies were discovered by accident. Usually, when astronomers go looking for really old objects in space, they look for those that are very red-shifted, since objects moving away from the observer effectively pull the light they emit into longer wavelengths, thus appearing redder. What astronomers don’t typically do, though, is study what appears to be empty space.