Don’t miss what’s happening in the southwestern sky after sundown the next few nights. The sky’s two brightest planets are pairing up for one of the prettiest conjunctions of the year. Yesterday evening I spotted the pair at 4:55 p.m. local time just 35 minutes after sundown. Venus was obvious about 10° high with Jupiter peeking out above it. By 5:15 p.m. the pair was sparklingly obvious hanging over the city of Duluth in the ruddy glow of twilight. Unmissable.
Tonight the planetary duo will be even closer — about 1.5° or three full moons — and reach closest approach of just under 1.5° on Sunday, Nov. 24. Their relative positions shift each night for two reasons. First, the apparent separation of Venus from the sun is increasing which makes the planet move up and away from the western horizon. Meanwhile, Jupiter is sliding westward in the opposite direction because of Earth’s motion around the sun. All celestial objects partake in this seasonal drift. Each night, all planets and stars in the eastern sky rise 4 minutes earlier while those in the west set 4 minutes earlier.
Like two cars in opposite lanes on a two-lane highway, Venus and Jupiter have been approaching each other for months. They’ll finally pass on Sunday. If you have clouds, be patient. You’ll still be able to see huddled close during the coming week. In fact, a beautiful sliver moon will join the pair on Thanksgiving evening (Nov. 28). If the sky is clear and you have a good view to the southwest make a point to go out for a look after dinner. Take your cell phone and try to get a picture of the three luminaries in a scene of your choice.
If you’ve an early riser look east Monday (Nov. 25) and you’ll see the three M’s — Mars, Mercury and a very thin crescent moon — and Virgo’s brightest star Spica. They’ll form a nearly line 25° long (2 1/2 fists) starting low in at the southeastern horizon with the moon and ending at Spica. Mars is the faintest of the trio at magnitude 1.7 (still easy to spot) with Mercury bright at magnitude –0.3.
At this time of year when we give thanks we can include the sky and the cosmic cycles that enrich our lives.