The globular cluster, called Messier 9, shines in this new photo from the Hubble Space Telescope.
The cluster Messier 9 contains hordes of stars swarming in a spherical cloud about 25,000 light-years from Earth. The object is too faint to be seen with the naked eye, and when it was discovered by French astronomer Charles Messier in 1764, the scientist could only resolve it as a faint smudge that he classified as a nebula. Hubble Space Telescope released a new picture of Messier 9 on March 16. The bluer points indicate hotter stars, while the redder stars are cooler. Messier 9 is what’s known as a globular cluster, containing some of the oldest stars in the galaxy in a clump that is thought to have formed together when the universe was much younger. These stars, which are about twice as old as the sun, are made of different materials than our star. They tend to lack the sun’s heavier elements, such as oxygen, carbon and iron, which were only present in larger quantities when the universe was older. Hubble’s new photo is the most high-resolution image ever taken of Messier 9, and reveals the ancient cluster as never before. So many details of the stars are visible, despite the fact that the whole image spans an area no bigger than the size of the head of a pin held at arm’s length. The Hubble Space Telescope (HST) is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter (7.9 ft) aperture telescope in low Earth orbit, Hubble’s four main instruments observe in the near ultraviolet, visible, and near infrared.