Greetings stargazers.
Although I address these “What’s Up in the Durango Skies” columns to stargazers, we should occasionally be moon-gazers, too.
I am writing this month’s column on the day of the full moon. This month the full moon happens near perigee, or the closest approach the moon makes to the earth in its elliptical orbit. This makes it appear slightly larger, or as popular culture has termed it “super.” Although the term was apparently coined in 1979, I don’t recall “super moon” being used commonly until the last decade.
Normally, any phase of the moon is bright enough to wash out good views of almost every deep space object. It can make the sky as bright as living in the middle of a large city. But that doesn’t keep any view of the moon through a telescope from being one of the most popular at star parties. When the moon is in a waxing crescent phase between new and first quarter, the craters and mountains are accentuated by longer shadows, especially along the terminator – the line between light and dark.
Historically, the moon has been a significant part of culture, religion, time keeping and even biology. I am currently reading “Our Moon” by Rebecca Boyle, and learning a lot of interesting things about the moon and its influence on human civilization that are outside my area of study. There is evidence that the existence of the moon may be why we have civilization in the first place.
The solar-based calendar that we use now was introduced by Julius Caesar. Before that time, Lunar-based calendars were more prevalent. Measuring time with the moon is often easier than with days or years, and we often do that subconsciously today. “I’ll be back in town in the middle of next month” is easier to remember than “I’ll be back in town in 43 days,” in which case you better start making tick marks in your planner.
Since there are slightly more than 12 moon cycles in a solar year, a lunar calendar adds “leap moons” every couple of years. A season usually has three full moons, but when a fourth must be added, the third out of the four is called a blue moon. The Christian, Jewish and Islamic calendars are based on the moon. For example, Easter always occurs on the first Sunday after the first full moon after the vernal equinox.
The moon has spurred technological innovations, many of which are a result of the race to the moon between the U.S. and the Soviet Union. Today the U.S. is in a second “moon race” with China to once again land humans on the moon, but this one dominates the public consciousness to a much smaller degree.
Useful links
Our Moon: https://rebeccaboyle.com/our-moon-how-earths-celestial-companion-transformed-the-planet-guided-evolution-and-made-us-who-we-are/
Astronomy picture of the day: http://apod.nasa.gov/apod/
An Astronomer’s forecast for Durango: http://www.cleardarksky.com/c/DrngoCOkey.html?1
Old Fort Lewis Observatory: http://www.fortlewis.edu/observatory
This month:
The planet Uranus reaches opposition Nov. 21. In an area as dark as the Four Corners, Uranus is visible to the naked eye at magnitude 5.5. It was not one of the five “wanderers” recognized by ancient astronomers because it is extremely dim and moves very slowly against the background of stars. You will need a good star chart or phone app to identify which dot to look for just to the south of the Pleiades. Even with the largest terrestrial telescopes, Uranus will be a tiny blue-green dot.
If you want even more of a challenge, Neptune at magnitude 7.8, is within 5 degrees northeast of Saturn. You will need a telescope to see that tiny dot.
Saturn, with its edge-on ring is still the brightest planet in the early evening sky until Jupiter rises at about 10 p.m.
The Leonid Meteor shower runs all month, but peaks Nov. 17. The evenings around then should be dark, as the new moon happens Nov. 20.
In the two weeks after the new moon, try to look at the moon periodically through binoculars or a telescope to see the interesting details.
Charles Hakes teaches in the physics and engineering department at Fort Lewis College and is the director of the Fort Lewis Observatory.
