Saturn and Regulus

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The planet Saturn is a slowpoke. It takes almost three decades to make even one circuit through the background of stars, so it can hang around particular stars for quite a while.

Case in point: Regulus, the brightest star of Leo, the lion.

Saturn has been lurking within about 10 degrees of Regulus for the last year. It skipped past the star last summer, moved well to its east, then stopped and moved back again. Right now, Saturn and Regulus are at their closest, separated by just a couple of degrees. But Saturn will start to pull away in a couple of days, and it won't come back around to Regulus until the year 2036.

Saturn moves so sluggishly because it's a long way from the Sun -- an average of close to 900 million miles. At that distance, its orbit around the Sun is huge. And objects that are farther from the Sun move more slowly than those that are closer. Add those two things together, and Saturn keeps a leisurely pace in its motion through the stars.

In fact, Saturn moves more slowly than any of the other planets that are visible to the unaided eye. So ancient skywatchers associated Saturn with people and things that had regal pedigrees -- so they could afford to move at a regal pace across the sky.

Saturn and Regulus stand high in the south at nightfall. Saturn looks like a bright golden star. Regulus is just a couple of degrees away, and looks a little bluer than its short-term neighbor.

Script by Damond Benningfield, Copyright 2008

For more skywatching tips, astronomy news, and much more, read StarDate magazine.