Santa Claus won’t be the only visitor to our night sky this Christmas Eve.
On Christmas Eve (December 24), Mercury will shine brightly in the sky above Earth, reaching its peak height above the horizon during sunset on Christmas Day, disappearing from the sky in 2022 before rising again in 2023 .
In two days to Christmas the closest planet to the Sun will reach its highest point in the sky during its current winter evening, 12 degrees above the horizon (slightly more than the width of a fist at arm’s length), while shining with a magnitude has been -0.6 as per in the sky (opens in new tab),
related: Night sky, December 2022: What you can see tonight [maps]
A phantom is the period of time during which an object in the Solar System is visible from Earth. Mercury can be seen in the morning or evening sky, depending on whether the planet is east or west of the Sun.
It rises when Mercury is in the east and sets after the Sun and can be seen in the evening. On the other hand when it is in the west, it rises and sets opposite the Sun and is visible shortly before sunrise. The ongoing evening impression of Mercury on the east side of the Sun lasts from December 4th to January 3rd.
Despite its increase in brightness, Mercury will still not be the “Star of Bethlehem” in the evening sky. The smallest planet in the Solar System will still be a challenge because this phantom is not one of the most prominent.
Additionally, your best bet is to act sooner rather than later to see the planet. That’s because Mercury will fade in brightness in late December-to-January as it passes through the middle and the Sun is heading toward an arrangement called an inferior conjunction.
During inferior conjunction, the illuminated sides of the planets face away from Earth. The result is that they appear as thin crescents that are barely illuminated.
Mercury is a planet that can only be seen from Earth during twilight which means it is difficult to spot during this thin crescent phase. As a result, the planet closest to the Sun will be easier to spot in the lead-up to Christmas Day than in the days following it.
Mercury is generally a difficult planet to see because as the closest planetary neighbor to the Sun it is often obscured by the glare of light from the star. The best time to attempt to view Mercury from Earth is therefore during the period when it is farthest from the Sun, known as “greatest dilation”.
These periods occur approximately every three to four months and last for a few weeks at a time. On December 21, during this current phantom, Mercury reaches its greatest elongation for the last time and thus its farthest distance from the Sun.
Whether you’re new to skywatching or have been doing it for years, be sure not to miss our guides to the Best Binoculars and Best Telescopes for Viewing Mercury or anything else in the sky. To capture the best skywatching images, we have recommendations for the best cameras for astrophotography and the best lenses for astrophotography.
Editor’s Note: If you’ve taken a cool photo of Mercury and want to share it with Space.com readers, send your photo(s), comments, and your name and location to spacephotos@space.com.
Follow us on Twitter @Spacedotcom (opens in new tab) or on Facebook (opens in new tab),