30 April 2013
On Sunday, 28 April 2013, Earth passes between the Sun and Saturn, a phenomenon known as opposition, and occurs every 377 days, approximately. This phenomenon is observed only for the superior planets. It resembles the event of the full Moon, as Saturn is opposite to the Sun in the sky, and is fully illuminated, as viewed from Earth. To an observer viewing the solar system from space, the Earth will be crossing between the Sun and Saturn, and the three objects will appear aligned on a straight line. During the opposition, the Earth-Saturn distance will be the shortest in this year, being about 1,320,000 km. Saturn is the most distant planet that can be seen easily with the unaided eye.
Saturn can be viewed after sunset. It will rise from the east, and will traverse the sky, closer to the south, setting by sunrise. It will shine as a moderately bright yellowish star. Observers using medium-sized to large telescopes can enjoy viewing Saturn’s rings, which distinguish it from all other planets. Saturn will remain bright through April and May.
Saturn can be identified easily, using the above sky map, which shows the eastern horizon after sunset. It lies on a line extending from the handle of the Big Dipper and passing through the star Spica. The star Arcturus lies to Saturn’s west.