The moon is our nearest neighbor in space, but it is often overlooked when stargazing. Many star parties will intentionally avoid evenings when the moon is in the sky. When the moon is between first quarter and third quarter (i.e. looking more than half full) most of the rest of the sky will be washed out, making it much harder to see clusters, galaxies and especially diffuse nebulae.
Despite its effect on seeing other objects, the moon is one of the most impressive things to look at through binoculars or a telescope. Seas, mountain ranges and craters are visible in astonishing detail compared with almost anything else you can look at in the night sky.
The details are most readily visible along the limb, or the boundary between sunlight and shadow. If you were standing on the lunar limb, the sun would be either rising or setting from your perspective. This is where shadows are the longest and most visible from Earth. Because the limb moves from day to day, every day provides an opportunity to get a good look at a new part of the surface. With shadows in mind, the full moon shows fewer details on the surface than any other time.
Many maps of the moon are available to help you identify what you are looking at. The Lunar Reconnaissance Orbiter was launched in 2009 and made a very detailed 3D map of the moon. One of the web links included with this column is to a map showing LRO data with scroll and zoom capabilities. You can download section maps showing named features, such as mountains and craters, but it is easy to be overwhelmed with information unless there is something specific you are trying to identify.
The UNLV map is much less detailed and is very useful in pointing out the major features. One favorite to identify is the Sea of Tranquility, where the first moon landing occurred. It is in the middle of the northeast quadrant. A very prominent crater is Tycho. It is in the southern center and has extremely long rays coming out of it.
A new word for the month is pareidolia, which means the tendency to see images or meaningful patterns in nebulous or random objects. This is why many of us see a face or other object pictured in the light and dark patterns on the “face” of the moon. Personally, I see the rabbit
The winter constellations around Orion are setting in the west at dusk, and the summer Milky Way doesn’t rise in the east until after 11 p.m. If you miss either of those reference points to navigate to other constellations, consider using the Big Dipper. It is near its highest point in the sky right after sunset.
At sunset on the evening of May 16, Venus, Mercury, the crescent moon and Mars will make a line in the western sky. If you include the Earth, this is a grouping of everything in the inner solar system.
There will be a total lunar eclipse early in the morning on May 26. Often called a blood moon, the moon appears red because it is illuminated only by whatever light from the sun shines through the Earth’s atmosphere around the edge. This ring of sunsets would look impressive from the moon. Because this eclipse occurs relatively close to perigee, you are likely to see the term supermoon used to describe it. But Super Blood Moon somehow sounds to me like something out of a zombie apocalypse movie.
Charles Hakes teaches in the physics and engineering department at Fort Lewis College and is the director of the Fort Lewis Observatory. Reach him at email@example.com.
LUNAR LIMB: https://en.wikipedia.org/wiki/Lunar_limb
ASTRONOMY PICTURE OF THE DAY: http://apod.nasa.gov/apod.
OLD FORT LEWIS OBSERVATORY: www.fortlewis.edu/observatory.
AN ASTRONOMER’S FORECAST FOR DURANGO: https://bit.ly/2eXWa64.
FOUR CORNERS STARGAZERS: https://bit.ly/2pKeKKa.