Two Rare Celestial Events Left in December—Here’s How to Catch Them

The year may be drawing to a close, but the night sky is not done dazzling us just yet. December’s final days are bringing two rare astronomical phenomena that skywatchers will not want to miss.

On December 25, the planet Mercury reaches its greatest elongation west, appearing at its farthest distance from the Sun in the morning sky. This marks the seventh and final time Mercury achieves this position in 2024, offering a fleeting opportunity to spot the elusive planet.

Mercury’s proximity to the Sun often makes it challenging to see, but during its greatest elongation, it becomes visible in the eastern sky just before sunrise. For the best chance of catching it, look toward the horizon around dawn. Using an interactive night sky map or stargazing app can help pinpoint its exact location.

Just five days later, on December 30, stargazers can witness a rare Black New Moon. This celestial event occurs when a second new moon takes place within the same calendar month. While the moon will be invisible in the night sky, its absence provides the perfect conditions for stargazing and astrophotography. Dark skies, free from moonlight, will make it easier to spot faint stars, constellations, and even distant galaxies. The Black Moon is often shrouded in folklore and mystery, adding an extra layer of intrigue to this rare occurrence.

Mercury and Venus are the only planets visible from Earth that experience greatest elongations, and 2024 marks a unique year: Venus has no elongations this year, making Mercury’s appearances even more significant. As for the Black Moon, its infrequent nature—only happening every couple of years—makes it a noteworthy event for astronomy enthusiasts and casual observers alike.
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Whether you are an avid astronomer or just enjoy looking up at the stars, these two events are a perfect way to close out 2024. Mercury’s greatest elongation is a chance to glimpse one of the trickiest planets to spot, while the Black New Moon offers a prime opportunity to take in the beauty of a dark, star-filled sky. Plan ahead by using tools like interactive night sky maps to ensure you do not miss these final celestial highlights of the year.