Because of the arrangement of its stars, it is called the Wishing Well Star Cluster—the sparkling cluster on the left side of my photo. The roughly 150 bright stars look like silver coins tossed into the bottom of a wishing well. It is one of the most impressive star clusters in the southern sky, nearly twice the size of the full moon. It is a mixture of orange-red giant stars and hot, blue stars. It is known for having served in 1990 as the very first test object and calibration target for the Hubble Space Telescope, which had recently been put into operation. With its sparkling, colorful individual stars, it stands out so clearly against the red and blue outer edges of the Carina Nebula—a vast, luminous region of gas and star formation in the constellation Carina.