The European Space Agency's star surveyor Gaia has finally sent some photos home from its trip. It captured a gorgeous image of a cluster of stars in the Large Magellanic Cloud, a satellite galaxy of the Milky Way, on its journey to create the most accurate map of our galaxy.
Gaia will observe one billion stars an average of 40 million times per day
Gaia launched on December 19, 2013 and will orbit around a virtual point in space (called L2) that lies 1.5 million kilometers away from Earth. During its orbit, Gaia will spin slowly and use two telescopes to focus the light from their separate fields simultaneously into one digital camera outfitted with nearly a billion pixels. This will allow Gaia to accurately measure the position and motions of just one billion of the Milky Way's nearly 100 billion stars over the course of five years. At the end of the mission, Gaia will have observed those stars 70 times, averaging 40 million observations per day, and will have hopefully created a map that will give researchers insight into our galaxy's origins and future.
Unfortunately, this first image might also be Gaia's last. Currently the star surveyor is going through a multiple-month testing phase to make sure the telescopes are perfectly aligned and focused and that all other instruments used are properly calibrated. This image was taken as part of that testing, but once it's over, Gaia's main operation mode will not involve sending images back to Earth. Even if this is Gaia's only message home, it's a beautiful one that shows how remarkable the chasms of our universe truly are.