The last half moon of 2023 will shine tonight (Dec. 19).
The now seven-day-old moon will be over half-lit in its first quarter phase, shining fairly brightly in the Pisces constellation. It will be 55% illuminated and is beginning to wax toward December's Full Cold Moon, which falls this year on Dec. 26. The moon will be visible in the east when it rises at roughly 12:30 local time until it sets just after midnight on Wednesday (Dec. 20).
Joining the moon in the night sky tonight will be a bright Jupiter, shining pale yellow just to the east of the moon. And to the west of the moon by roughly the same distance will be Saturn, much dimmer than Jupiter but nonetheless offering skywatchers the chance to see the solar system's two largest planets on either side of our companion in the night sky.
Related: Night sky, December 2023: What you can see tonight
Looking for a telescope for the next night sky event? We recommend the Celestron Astro Fi 102 as the top pick in our best beginner's telescope guide.
During the half-lit moon tonight, our planet's natural satellite will hang in the Pisces constellation. Named for the Latin word for "fishes," Pisces is one of the largest constellations of the night sky but is fairly dim, making many of its stars difficult to see with the unaided eye or near urban areas.
As seen in the sky, Pisces is usually depicted as two fish swimming at right angles to one another, attached by a cord or string. According to Greek mythology, the fish themselves represent the goddess Aphrodite and her son, Eros, who both turned into fish and jumped into the Euphrates River to escape the monster Typhon.
Pisces is located adjacent to two other water-related constellations: Aquarius, the water-carrier and Cetus, known as either the whale or the sea monster.
After tonight's meetup with the fishes of Pisces, the moon will begin setting later each day leading up to the full moon, becoming visible for more of the night. On Dec. 26, the Full Cold Moon will rise almost in parallel with the setting of the sun, remaining visible throughout the entire night until the sun rises the next morning. That's because during a full moon, the sun and the moon are positioned on opposite sides of Earth, leading to the fully illuminated face of the moon we see.
As an avid moonwatcher myself, I find there's nothing better than gazing up at the moon through a telescope or binoculars and seeing the craters and mountain ranges up close, particularly during a half-lit quarter phase like tonight when the contrast created by the "lunar terminator" (the boundary line between night and day on the moon) really brings out stunning details of the lunar surface.
If you want to get a good look at what the lunar surface has to offer as seen from your own backyard, garden or wherever you can see the sky, don't miss our guides on the best binoculars and best telescopes to help you choose the right optics for you.
If you're looking to snap a photo of the moon at first quarter or any other phase, check out our guide on how to photograph the moon. And if you don't have everything you need to photograph the night sky, consider our best cameras for astrophotography and best lenses for astrophotography.
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