... Jets from Comet Churyumov Gerasimenko . ... Where do comet tails come from? ... These two mighty galaxies are pulling each other apart. Known as the "Mice" because they have such long tails, each spiral galaxy has likely already passed through the other. The long tails are created by the relative difference between gravitational pulls on the near and far parts of each galaxy. ... Our Galaxys Magnetic Field from Planck . ... The Milky Way over the Seven Strong Men Rock Formations . ...