Key Takeaways:
First Quarter Moon occurs at 7:54 P.M. EDT, offering North American observers a chance to spot the so-called Maginus sunrise ray. Now in Sagittarius, the Moon remains above the horizon until close to midnight, offering several hours to watch the ray’s progress unfold.
The 100-mile-wide (160 km) Maginus Crater, located in the lunar south, is just seeing sunrise this evening. As the Sun slowly breaks over the crater’s eastern rim, it first spills through the divot created when a later impact blasted away part of the crater wall (resulting in the small crater Maginus E to Maginus’ east). This creates a V-shaped ray of light that spreads across the crater floor over time, illuminating a thin slice while the rest remains in shadow until the Sun breaches the top of the rim.
Because this process is slow and the Moon is above the horizon all evening, you can take your time observing it. Check in on the crater early, then spend some time with other targets. Just make sure to return to the Moon periodically throughout the night to check on the ray as it makes its way from east to west across Maginus’ floor.
Sunrise: 6:55 A.M.
Sunset: 6:45 P.M.
Moonrise: 2:35 P.M.
Moonset: 11:19 P.M.
Moon Phase: Waxing crescent (47%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.
For a look ahead at more upcoming sky events, check out our full Sky This Week column.
