Look at the night sky. How many stars can you see? For an average observer under a dark sky, you might count a few thousand twinkling lights. A new set of satellite images, however, tracks almost two billion stars — the most high-precision map of the sky yet.
Knowing where the stars are located is just one step to understanding the sky around us, though. With this data from the European Space Agency (ESA) Gaia mission, scientists can launch all sorts of scientific investigations. For example, they can look for "runaway" stars streaking across the sky, or continue the hunt for the sun's lost siblings.