Since late last month, Venus has been playing tag with the evening planets at dusk, providing lots of pretty viewing and photographic opportunities. I hate to break the news, but that’s about to end. Venus is now nudging toward Saturn and will pass it in conjunction on Dec. 10-11. Jupiter’s hunkered down in bright twilight and will soon depart the evening sky followed by Saturn several weeks later. Come Christmas Day Venus will stand alone in the western sky, the sole bright planet easily visible at dusk.
Such is the way of the solar system where nothing stands still. Watch the animation, which spans from Dec. 5-12, and you’ll see two things happening. Venus moves up and away from the sun, and Jupiter and Saturn move toward it. As we discussed in an earlier blog, what’s really happening is that Venus’s apparent distance from the sun is increasing from our perspective here on Earth. At the same time, Earth’s orbital motion around the sun makes the stars and planets slowly drift westward over time every about 1° a day equal to 4 minutes of time.
After Jupiter and Saturn pass in front of the sun in conjunction, they’ll move to its other side and return to the morning sky. There, they’ll join Mars for some wonderful conjunctions in the new year ahead. Stay tuned!