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Tonight Is The Best Time To View The Moon

Photo from Pixabay

The full moon on a cloudless night is a thing to behold, especially when viewed from a perch up high in the mountains or from a wide expanse of land unobscured by tall buildings. It’s luminosity against the darkness is a reminder of space and the wonders of the universe beyond Earth.

While it may seem like the optimum time to view the moon through a high-powered telescope when it is as its fullest, astronomers say that’s not the case at all. When a full moon is viewed from a telescope, it’s not only glaringly bright, it also looks like a flat, one-dimensional latte instead of the globe people expect it to be.

Skywatching Columnist Joe Rao from says that the best time to view the moon is when it is a “half moon,” also called the first or last-quarter lunar phase, and on the days leading up to or just after those quarters. Those times give the most to look out for when viewing the moon, along the line separating its light and “dark” sides, the sunrise-sunset line called the “terminator.”

Around the time of these phases, observers can use small telescopes or even binoculars to take a good look at the moon, and see an incredible play of light and shadow along the terminator. Features close to this line will also be clearly visible. The terminator also appears as a sharp line, because the moon has no twilight. If the Earth were to be viewed from the moon, the line would be softer due to the twilight zone that diffuses the night-day break.

The moon will be at its first-quarter phase tonight at 8:56 EDT, making it exactly 50% illuminated.

Anyone observant enough, even with the naked eye, will be able to see the terminator perfectly dividing the moon, with the bright half on the right and the dark half on the left.

Features such as lunar mountains will be visible, as the sun is lighting them from the right. A few hours before the first-quarter, the terminator will look to be slightly concave, or in its crescent shape, and after several hours after the first-quarter phase, will be slightly convex as it waxes.

Viewing a first-quarter moon is also easier on the eyes than viewing a full moon, because of the brightness. The first-quarter moon is just 9% as bright as a full moon because it is heavily shadowed, even on the lighted half. Observers looking through a telescope or binoculars will spot large, dark areas called seas or maria, which are flat lava plains.

A full moon, on the other hand, is almost completely lighted up, especially around the center. The sun shines straight down on everything, even the tiniest crevices, so there are no shadows. On very dark nights, a full moon can even cast shadows on Earth.

At its first-quarter phase tonight, observers will want to keep an eye along the terminator for the famed Copernicus crater. Named after the historic 16th-century astronomer Nicolaus Copernicus, the crater was nicknamed the “Monarch of the Moon” by lunar cartographer Thomas Gwyn Elger due to its massive size.

At 58 miles wide and 2.3 miles deep, this relatively young impact crater is the most obvious moon feature when it appears along the terminator. Those still looking on the days after tonight will see the crater in full sunlight, surrounded by bright rays extending out for 500 miles, like a sunburst of sorts. The crater Tycho, located farther south of Copernicus, has a similar but more extensive system of rays.

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