August’s Full Moon shines brightly in the sky tonight, showing off the rayed crater Tycho.
- The August full moon, also known as the Sturgeon Moon, reached its full phase at 3:55 A.M. EDT.
- Observing the full moon presents challenges due to its brightness, which can hinder dark adaptation and minimize shadow detail on the lunar surface.
- Despite these challenges, prominent features like the ray systems emanating from craters such as Tycho, Copernicus, Proclus, and Petit are readily observable.
- Tycho crater, notable for its extensive ray system, offers significant details for observation, including a central peak approximately 5,000 feet high.
Full Moon occurs at 3:55 A.M. EDT this morning. August’s Full Moon is also called the Sturgeon Moon, so named by Native Americans for the prevalence of these fish in late summer.
You might think it’s quite easy to observe the Full Moon, but there are a few complicating factors. First, the Full Moon is quite bright, so looking at it through binoculars or at telescope can be uncomfortable (though not dangerous). Further, observing the Full Moon will offset any dark adaptation your eyes have gone through, making it more challenging to see any other objects you want to observe until your vision adjusts once more. And finally, during the Full phase, the Sun appears directly overhead from the lunar perspective — essentially, it is noon on the Moon, and shadows are at their shortest. This can wash out much of the detail on the landscape.
But none of this means the Moon cannot or should not be observed when it’s Full! During this phase, some features are on stunning display, such as the long ray systems streaking away from craters like Tycho, Copernicus, Proclus, and Petit. These rays are ejecta — subsurface material that was excavated and thrown far away during the impact that created these craters.
Tycho, located in the lunar south, has some of of the longest and most impressive rays to observe. The crater stretches some 53 miles (85 kilometers) across, but its rays cover much of the Moon’s nearside, even extending north of the lunar equator. Trace these light-colored rays with your eyes and note how they appear to cover many other features along the way. This means they are younger than the craters, maria, and mountains that lie underneath them. Astronomers estimate Tycho is a mere 110 million years old or so.
Tycho itself has plenty to explore within its bounds, including a central peak rising some 5,000 feet (1,520 meters) above the crater floor. Take your time scanning the region with a small telescope; even under the noontime Sun, there is plenty to observe here.
Sunrise: 6:06 A.M.
Sunset: 8:04 P.M.
Moonrise: 8:34 P.M.
Moonset: 6:13 A.M.
Moon Phase: Full
*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.
