Sunday, February 18, 2007
On Feb. 10, the ringed planet Saturn was at its closest point to the Earth for the year, a point called opposition. At the moment of opposition, the Earth is positioned exactly between Saturn and the sun, placing the two planets as close together as they can be.
Oppositions of Saturn happen about every 12 1/2 months as the faster-moving Earth gains a lap on Saturn and catches up to it from behind. This year, on Feb. 10, Saturn was 762 million miles from Earth.
You can spot Saturn, without any optical aid, rising in the eastern sky just after sunset. It appears as a bright, yellowish star that doesn't twinkle like a regular star, but gleams with a steady light.
Saturn is surrounded by a set of magnificent rings that completely encircles the planet's equator. The rings are composed of millions of tiny ice particles - probably particles blasted off one or more of Saturn's small, icy moons by the impact of a comet.
And speaking of moons, Saturn has quite a large family of worlds and mini-worlds orbiting around it. To date, astronomers know of 50 moons orbiting Saturn. The largest is Titan, a planet-sized moon and the only moon in our solar system that has a thick, cloudy atmosphere.
Saturn, Titan and many other moons are being studied by a tiny, artificial moon - NASA's Cassini spacecraft, which was placed into orbit around Saturn in July 2004. Spectacular photographs of Saturn, its rings and its moons are beamed back to Earth daily, helping us understand the mysteries of this distant world. You can check out the latest Cassini images of Saturn at http://Saturn.jpl.NASA.gov.
This winter, Saturn is positioned near the head of Leo the Lion, and Leo's brightest star, Regulus. Icy-blue Regulus rises just minutes after Saturn.
If you own a telescope - even a small one - try aiming it at Saturn. Saturn offers the biggest "Wow" factor of any other object visible in a small telescope. You can easily see for yourself the magnificent icy rings and the largest moons of Saturn. Try looking at Saturn on Feb. 24, March 5 and March 13 when the giant moon Titan appears farthest from the rings and is easiest to see. Titan will look like an orange "star" just beyond the edge of the rings.
On the night of March 1, don't miss the beautiful sight of the full moon and Saturn rising side by side over the eastern mountains just after the sun sets in the west.