Astronomy Picture of the Day

Explanation: Not a bright comet, 67P/Churyumov-Gerasimenko now sweeps slowly through planet Earth's predawn skies near the line-up of planets along the ecliptic. Still, this composite of telescopic images follows the comet's progress as it moves away from the Sun beyond the orbit of Mars, from late September (left) through late November (far right). Its faint but extensive coma and tails are viewed against the colorful background of stars near the eastern edge of the constellation Leo. A year ago, before its perihelion passage, the comet was less active, though. Then the Rosetta mission's lander Philae made its historic landing, touching down on the surface of the comet's nucleus.