Every month I eagerly await the rise of the full moon. Sometimes it’s cloudy, but often the sky is just clear enough to catch a glimpse of one of the most amazing and accessible sights in the universe.
The key to a successful moonrise, of course, is finding a location with a clear eastern horizon, such as a lake, field or mountain top. The farther you can see to the bottom of the sky, the more rewarding the experience will be, including the explosive moment when the moon first appears.
Article by Bob King
I know this sounds obvious, but the moon rises because the Earth rotates, not because it moves itself. As the planet rotates, we turn toward the full moon on the eastern horizon around sunset. When it is due south around midnight local time, we see it directly in front of us, with the sun behind us and out of our sight below the northern horizon. As the moon moves into the western sky and eventually reaches the horizon, we turn away from it and face the rising sun.
Article by Bob King
On Monday evening, August 19, the moon is full, rising in the southeastern sky over the Duluth-Superior area at 8:33 p.m. For other cities, use this moonrise calculator. The full moon in August is called the Sturgeon Moon because it was one of the best times of year for fishing for Native Americans living in the Great Lakes region. To the Anishinaabe, it is known as the Manoominike-giizis, or Rice Moon. The wild rice harvest in northern Minnesota usually begins in the second half of August.
If you know when the moon will rise, arrive at your observing location at least 15 minutes beforehand to get your bearings. I recommend downloading the free stargazing app Stellarium Mobile to your phone. Once installed, it will display a live view of the night sky to help you find the spot on the horizon where the moon will rise.
Here are 10 different ways to observe and enjoy the view. If clouds intervene, try the following night when the moon is still almost full.
Article by Bob King
1. Color — Smoke from wildfires darkens and reddens the moon, but in clear air it rises orange and bright. Moonrise is the moment when the top of the moon first appears on the horizon. If you’re lucky enough to have no obstruction to your view, that first glimmer of moonlight looks surprisingly like a bright star.
When the moon rises, we look through the densest layer of air at the bottom of the atmosphere. Air molecules scatter the moon’s violet, blue and green light so that only the warmer colors reach our eyes – the reason why a low moon appears orange.
2. form — That same dense air acts like a prism, “lifting” (breaking) the lower half of the Moon up into the upper half, squashing the otherwise round Moon into a watermelon shape. As the Moon rises higher, the prismatic effect diminishes and the Moon takes on its familiar round outline. Watch for distortions in the Moon’s outline as it rises. Layers of air with different temperatures and densities stacked on top of each other can give it the strangest shapes!
Contribution by Bob King (left) and Austin Jarboe
3. Green cheese effect — In clear, smoke-free air, look at the moon with binoculars shortly after it rises. The upper edge may appear green and the lower edge red. Again, the atmosphere is the cause. Like a prism, it scatters the moonlight into a rainbow spectrum with red at one end and green-blue at the other.
Article by Bob King
4. Glitter path — If you look out over a lake, a glittering trail of reflected moonlight stretches from the shore straight to the moon. As the moon rises, it becomes brighter. Moonlight reflecting off the countless waves creates the shimmering path. On calm nights, the trail is narrow and mirror-smooth, but when the wind picks up, it becomes wider and more structured.
5. Feel the rotation of the earth — Watching the rising moon is the perfect time to see the Earth’s rotation in action. Imagine what really happens. The moon essentially sits still below the horizon until the rotating Earth brings it into view. While the moon does moves eastward in its orbit, its movement in 5 minutes is practically imperceptible to the eye. The Earth is the main moving machine here.
Contributed / AlexWorth91, CC0
6. Moon Illusion – For many of us, the moon appears larger near the horizon than it does above us. We know it’s an illusion because the size of the moon is essentially constant. Although there is no definitive explanation for it yet, its bloated appearance has to do with cues our brain receives from the environment in which we see the moon. At moonrise, surrounded by familiar objects like trees and buildings, we perceive the moon as larger than when it is high up in the empty sky. Click the link to learn more.
Article by Bob King
7. Crazy cartoons — Shortly after moonrise, we can see that the moon has darker areas (the seas) and lighter regions (lunar highlands). Many people like to imagine a face or an animal in the light and dark areas. I always see two big eyes, a small nose, and a huge mouth missing many teeth. Others see a woman or even a rabbit. If you’re observing with children, ask them to connect light and dark to form their own patterns.
Article by Bob King
8. Moon exploration — With binoculars, you can easily identify the lunar seas (“maria” in Latin) and prominent craters. The easiest to spot is probably the 93-kilometer-wide crater Copernicus. Use my little map to help you find your way.
Contributed / Stellarium
9. Saturn Finder — About an hour after moonrise on August 19, you’ll see a single bright star about an outstretched fist to the left of the moon. That’s Saturn. The following evening, August 20, the waning moon will shine directly below the planet. The glare may make Saturn difficult to see, so have your binoculars ready.
10. Hiking without a headlamp — Once the moon is in the sky, find a place with as little artificial lighting as possible and take a walk in its light. Try not to use a flashlight. I promise you that your eyes will quickly get used to the soft glow of the moon. The contrast between dark shadows and illuminated areas is more extreme in moonlight than in sunlight, which adds an air of mystery to even the most mundane landscapes. Have fun.
“Astro” Bob King is a freelance writer and retired photographer for the Duluth News Tribune. Reach him at [email protected].
