NASA described that the stars appear in blue and white lights because of the X-rays they give off, which the Chandra X-ray detected. The stars are surrounded by swirls of gas, which look like pine needles of an evergreen tree. They are green because they represent the light in the visible spectrum, according to NASA.

NASA is getting into the festive spirit, sharing some stunning images of the Christmas Tree Cluster and the Cosmic Wreath. The star clusters are a marvel of deep space, showcasing the beauty to be found beyond our planet,

NASA astronauts including Suni Williams, Nick Hague and Don Pettit shared a special Christmas message from the International Space Station.