Lunar Triangle / Departing Venus Runs Into Mercury

The moon, Jupiter and Spica gather for a pretty grouping on Tuesday night, March 14. About three outstretched fists to their upper left, you’ll also see the bright, orange-red star Arcturus in the constellation Bootes. Created with Stellarium

After a busy weekend watching moonrises and lunar halos a guy needs a break. Today we catch our breath, astronomically speaking, so we can prepare for an exciting moon-star-planet conjunction and the return of Mercury on Tuesday.

We’re now on UUT, universally unwanted time, better known as daylight saving time.  Studies have shown that DST doesn’t save energy, and no one I know likes getting up an hour earlier or remembering they have 13 clocks to change including the dreaded car clock. Some of us have fuzzier feelings about getting the hour back in November, but I think most would be happier to be rid of it altogether.

Mercury returns to the evening sky just as Venus prepares to leave it. Look for the two planets one fist apart Tuesday evening low in the west after sundown. They’ll be closest together (about 8 degrees) on the Saturday the 18th and about level with each other. Created with Stellarium

Let me give you an example of why the time change can be difficult on skywatchers. Tuesday evening (March 14) there’s a sweet alignment of the waning gibbous moon, Jupiter and Virgo’s brightest star, Spica. They’ll form an attractive and eye-catching triangle in the eastern sky when they clear the horizon after about 10:30 p.m. Were it not for daylight time, the trio would be easy to see around 9:30 p.m. and accessible to many more observers.

But no. Because we advanced our clocks an hour forward, this pretty sight comes up around 10:30, when many of us will be standing in the bathroom brushing our teeth before turning in. Still, I hope you go out to see it 🙂

As Venus approaches conjunction with the sun on March 25, it’s becoming a very thin crescent. A pair of carefully-focused 7x to 10x binoculars will show the shape. Try it – you’ll be amazed. Credit: John Chumack

Yet another event happens tomorrow that’s easier on the sleep schedule. We talked recently about Venus slowly then more suddenly dropping back toward the sun in the evening sky. Lo and behold, just as Venus departs, we get a substitute planet! Mercury rises up in the western sky and puts in one of its best appearances of the year beginning this week and continuing into the first week of April.

Currently as bright as Sirius (the brightest star), Mercury should quickly become fairly easy to see as the week wears on. To be sure you see it, find a spot with a wide open view of the western horizon and start looking for the two planets about a half hour after sunset.

** To learn more about the motions of the inner planets and how and why conjunctions occur, pick up a copy of my book Night Sky with the Naked Eye at Amazon or Barnes & Noble.