The picturesque lineup of Jupiter, Venus and a crescent moon could be a one-night-only showing for Beaufort County stargazers.
Although the three celestial features also will appear Sunday, the local sky might be cloudy then, according to Jolie Packet of the National Weather Service in Charleston.
So tonight is the night.
"Initially, Saturday night should be pretty good," she said. "It will be much more cloudy Sunday."
University of South Carolina Beaufort chemistry professor Gordon Sproul said the best time to stargaze will be from twilight at 6:17 until about 10 p.m. "Get a clear view of the western sky. If you can see the sunset, that's the ideal setting," he said.
Sproul said the brightness of Jupiter and Venus can be seen with the naked eye, but those with telescopes should be able to see Jupiter's rings.
Mars also will make an appearance about 45 minutes after sunset, Sproul said. The three planets won't line up perfectly. Jupiter will be the highest in the sky, with Venus below it, and Mars will sit just above the horizon.
After this weekend, the moon goes on its way. But Venus and Jupiter will continue to converge until they are only three degrees apart in mid-March.
The sunset convergence occurs twice or so per decade, each time within a few years of a dawn convergence.
Terry Richardson, College of Charleston senior astronomy instructor, will be out to watch the odd planetary convergence, not as a professor but as a photographer.
"It's a great thing to photograph," he said. "The planets are so light they stand out against the sky as it darkens." When the moon moves in, that makes for a real show, he said.
The Charleston college's astronomy lab plans to open its observatory and telescope for a visitors night March 16, and the convergence will be one celestial sight to be seen.
This convergence has not stirred up the same excitement as the past harmonic convergence, an alignment of several planets that spurred "energy shifts" and mass meditations when it last occurred in 1987.
Postandcourier.com reporter Bo Petersen and Beaufort Gazette reporter Anne Christnovich contributed to this report.