Don’t miss the half-lit disk of Earth’s natural satellite gracing the night sky this week as the moon hits its first quarter phase while clutched in the grasp of a celestial scorpion.
The moon reaches first quarter at 2:25 a.m. (0625 GMT) on Aug. 31, when it will be located firmly below the horizon for viewers in the U.S. The best time to catch the half-lit moon will be at sunset on Aug. 30, when the half-lit moon will shine less than 20 degrees above the southwestern horizon. A handy tip: the width of your fist held at arm’s length covers about 10 degrees of sky.
At this stage, the right side of the lunar disk will be lit by sunlight, while the left remains veiled in shadow. The moon will appear close to the right of the red supergiant star Antares on Aug. 30, with the stars of the constellation Libra — which once represented the claws of the great scorpion represented in Scorpius — visible to the right of the lunar disk.
Earth’s moon will set a little over three hours after the sun on Aug. 30, so be sure to find a location with a clear view of the southwestern horizon to get the most out of the cosmic pairing.
The next major lunar milestone will be the full moon phase on Sept. 7, which will coincide with a total lunar eclipse, wherein Earth’s shadow will pass directly over the satellite’s ancient surface, transforming it into an ominous blood moon.
Read more: Total lunar eclipse 2025: Everything you need to know about the next blood moon
Interested in exploring the moon for yourself? Then why not check out our roundups of the top telescopes and binoculars for exploring the night sky in 2025. Those new to the hobby may also want to read our roundup of the best smartphone astronomy apps available in 2025, which help you navigate the night sky with the aid of augmented reality technology.
