... A new comet has brightened unexpectedly and is currently visible to unaided observers of southern skies. ... The Coma Cluster of Galaxies . ... Each of these galaxies houses billions of stars - just as our own Milky Way Galaxy does. ... Deep inside Centaurus A, the closest active galaxy to Earth, lies ... another galaxy! ... The result, shown above, is the most complete sky map of the most common visible light emitted from the most abundant element in our Galaxy: hydrogen. ... Earth Rise . ...