Nights Of The Barley Moon

The nearly full moon shines above Duluth’s Aerial Lift Bridge one August ago. The traditional name of the August full moon is the Sturgeon Moon, but it’s also named Barley, Grain and Green Corn Moon. Full moon names are all associated with the seasons. Bob King

Just a reminder that the moon will be full around 8:30 tomorrow morning (Aug. 14) Central Time. That means both tonight and tomorrow night the moon will rise about 99.5 percent full. For most of us it will appear full with the naked eye and only betray a slight out-of-roundness in binoculars or a telescope.

Here are some things to look for with the naked eye or binoculars tonight and tomorrow. The lunar “seas” are dark areas blasted out by asteroids between about 3 and 3.5 billion years ago that later filled with magma from deep below the crust. Craters look like white spots compared to their more three-dimensional appearance at half-phase. Bob King

The full moon is by far the worse time to see all the the rough and subtle details that low-slanted sunlight coaxes from the craters and valleys that carve the lunar landscape. The sun shines straight into the moon’s “face” like a bright spotlight on an actor’s face on stage. This type of direct lighting hides all shadows, and without shadows the moon looks flat and pasty. Compare this to half-phase, when the sun shines off to one side (below), highlighting the subtlest of textures.

Around first quarter phase, when half the moon is lit up by the sun, look at how much more crater detail you can see. That’s because the sun is shining off to the side (right). At the terminator, the boundary between day and night on the moon (at left), slanted sun rays cast shadows that reveal rich detail in craters and other lunar features. Bob King

Point a telescope or binoculars at the moon the next two nights and you’ll see a pastiche of gray and white with only a hint of shading along its left (eastern) edge. Everything is brightly illuminated in shadowless lighting. Craters look like white blotches.

 

Last month, the full moon shone from Sagittarius, near the lowest point in the great circle it makes around the sky from full moon to full moon. In August, the full moon begins its climb northward, appearing in Capricornus to the left or east of Sagittarius. Next month, it will climb higher yet into Aquarius. Stellarium

Tonight (Aug. 14) the moon rises shortly before sunset for many U.S. locations; tomorrow night, a little after. Click here to find the time of moonrise for your location. The Barley Moon shines in Capricornus, a faint, triangular-shaped constellation to the east (left) of Sagittarius and Saturn. It should be a beautiful sight.

3 Responses

  1. Edward M. Boll

    I just picked up the 2020 farmers almanac. It stated that on December 21, 2020 Jupiter and Saturn will be visible low in the southwest evening sky appearing so close as to almost look like one star.

    1. astrobob

      Hi Edward,
      That’s true! They will be just 6 arc minutes apart. Very close but I think we’ll be able to split them with the naked eye. Very close though! The separation is almost identical to Alpha Capricorni.

    2. astrobob

      Ed,
      On another note, it’s good to know the Farmer’s Almanac is out already. I’ve been a faithful purchaser since I was 13.

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