Catch the Duo of the Moon and Mercury in the January Sky

~2 min

Last week, the observers had a chance to enjoy the rare triple conjunction of Mercury, Jupiter, and Saturn lighting up the evening sky. This week, try to catch the beautiful duo of the pale, thin crescent Moon and the closest planet to the Sun, Mercury.

The conjunction of the Moon and Mercury

The young waxing crescent Moon and Mercury will shine close in the sky the next several days. On January 14, 2021, at 03:14 a.m. EST (08:14 GMT), the 1-day old Moon will pass 2°19' to the south of the speedy little planet. Our natural satellite will be at a magnitude of -8.3, and Mercury will shine at a magnitude of -0.9. You’ll find them dancing among the stars of the constellation Capricornus.

You’ll need clear skies and an unobstructed horizon to witness this spectacular astronomical duo. However, it will be rather challenging to see: the slender lunar crescent and the elusive planet will pop into view in the dusk after sundown and then follow the Sun beneath the horizon before nightfall. You can try to see both sky objects with an unaided eye. And don’t worry if you miss the duo on January 14 — try again on the following days, when the brighter lunar crescent will stay out longer above the horizon.

Let the illuminated side of the crescent Moon be your guide — it will help you to find Mercury, as it points to this speedy planet. Or simply use the astronomical app Star Walk 2 to locate the Moon and Mercury: tap the magnifier icon, type in “Moon” or “Mercury”, select the corresponding search result, and Star Walk 2 will show you their exact position.

Watch for elusive Mercury

These days Mercury is the second-brightest “star” of the night sky; only the brilliant star Sirius outshines the little planet. However, the sunset afterglow might interfere with the observation of Mercury as it shines close to the horizon after sundown. If you can’t see this little planet with the naked eye, binoculars will help you get a better view.

According to the Canadian astronomer Chris Vaughan, Mercury will become more easily visible every night this week, especially between about 5:30 p.m. and 6:00 p.m. local time. The speedy planet will move farther away from the setting Sun day by day and reach its greatest eastern elongation on January 24, 2021. In the next few weeks, you can enjoy the favorable apparition of Mercury at evening dusk.

Wishing you clear skies and happy observations!