Astronomers using data from the NASA/ESA Hubble Space Telescope and other observatories have performed an accurate census of the number of galaxies in the universe. The researchers came to the surprising conclusion that the observable universe contains at least two trillion galaxies. The results also help solve an ancient astronomical paradox — why is the sky dark at night?
During the Perseid meteor shower, second-largest asteroid 2 Pallas passed close to the southeast of globular cluster Messier 15 in the constellation of Pegasus. The minor planet still lies in the vicinity of this beautiful deep-sky object, reaching opposition on 20 August — here’s our in-depth guide to Pallas at its best.