Do you live in the Southern Hemisphere, or the northern tropical latitudes? If so, you have a golden opportunity to catch the young lunar crescent bunching up with the planet Mercury and the star Spica as night falls on September 25 and/or September 26. Look for the moon, Mercury and Spica to pop out over the sunset point on the horizon as dusk ebbs into darkness. Not in Southern Hemisphere or tropics? Try it, anyway! Binoculars will help you scan for the pair along the sunset horizon.
Presuming a level horizon, Mercury sets a whopping two hours after sunset at mid-temperate latitudes in the Southern Hemisphere, and Spica sets about one and one-half hours after the sun. The moon’s setting time varies, though, depending on longitude. Click here to find out sunset/ moonset times in your sky.
The Southern Hemisphere has the big advantage for catching the young moon, Mercury and Spica after sunset on September 25 and 26. The best time to see the young moon (plus any nearby planet or star) in the evening sky is in early spring. Since it’s now early spring for the Southern Hemisphere, but early autumn in the Northern Hemisphere, the southerly latitudes have the best chance of spotting the young moon, Mercury and Spica after sunset on September 25 and 26.
Bottom line: The young moon, Mercury and star Spica are in the sunset direction on September 25 and/or 26, as night falls. Best seen from Southern Hemisphere. Northern Hemisphere viewers … try it! Binoculars may be helpful.
Bruce McClure has served as lead writer for EarthSky's popular Tonight pages since 2004. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also writes and hosts public astronomy programs and planetarium programs in and around his home in upstate New York.