Hubble time! 🌌 M72 is a collection of stars, formally known as a globular cluster, located in the constellation Aquarius roughly 50 000 light years from Earth. The intense gravitational attraction between the closely packed stars gives globular clusters their regular, spherical shape. Roughly 150 clusters such as this have been discovered in the Milky Way galaxy. The striking variety in the colour of the stars in this image of M72, particularly compared to the original image, results from adding ultraviolet observations to the previous visible-light data. The colours indicate groups of different types of stars. Blue stars are those in the cluster that were originally more massive, and have now reached hotter temperatures after burning through much of their hydrogen fuel; the bright red objects are lower-mass stars that have now become red giants. Studying these different groups help astronomers to understand how globular clusters, and the galaxies they were born in, initially formed...