The NASA/ESA Hubble Space Telescope has taken a very detailed image of the bulge globular cluster NGC 6638. This Hubble image shows the bulge metal-rich globular cluster NGC 6638. Image credit: NASA / ESA / Hubble / R. Cohen. Globular clusters are dense systems of very ancient stars, gravitationally bound into a single structure about 100-200 light-years across. They are among the oldest known objects in the Universe and are relics of the first epochs...
