See Mercury and the moon on August 29

See Mercury and the moon

Can you spot Mercury in the evening sky just after sunset on August 29, 2022? Use the moon to guide you to Mercury. Northern Hemisphere observers will face much more of a challenge to see it than those south of the equator.

From the Northern Hemisphere, the geometry is poor. Mercury is wide to the left of sunset but close to the horizon, giving you less than an hour to spot the fleet-footed planet before it, too, dips below the horizon. On August 29, though, the thin waxing crescent moon, complete with earthshine, acts as your guide. Notice that the lighted portion of the crescent on August 29 points to Mercury.

Use binoculars to scan near the horizon as soon as the sky begins to darken and the sun is safely gone. Does Mercury appear to twinkle because of the thick atmosphere between you and your target? You can also take some time to check out the moon’s terminator, or dividing line between day and night.

The bright stars that first appear in the west as the sky begins to darken are Spica to the south and Arcturus, above. Arcturus is the brightest star in the northern half of the sky. On the next night, August 30, the moon will appear closer to Spica than to Mercury.

The view from the Southern Hemisphere

If you’re in the Southern Hemisphere, Mercury and the moon will be easier to spot. Instead of ringing the horizon with the sun, the two will stand above the sun. This perpendicular alignment with the horizon gives you about two hours to spot Mercury before it sets. You’ll see Spica above Mercury and the moon, with Arcturus to the right. Check Stellarium.org for the view from your location.

Bottom line: Use the moon to help you spot Mercury on August 29, 2022, when the duo appear close together at sunset.

For more great observing events in the coming weeks, visit EarthSky’s night sky guide