... Epimetheus and Janus, two small moons of Saturn, actually switch positions as they orbit their home planet. The orbital radii of the moons are strangely separated by less than the radii of the moons themselves: about 50 kilometers. ... Last month, a Soyuz TMA-7 spacecraft docked with the International Space Station. ... This October, Mars has become a bright, yellowish star in planet Earth's sky as it approaches oppositon, the period when Mars and Earth pass close as they orbit the Sun. ...