November 27, 2010
Celestial Events of Note: December 2010
Here is a summary of what I feel will be the most interesting and compelling “celestial events” for December, 2010
Lunar Occultation of Mars, Monday, December 6th
The “Red Planet” Mars will disappear behind a one day old crescent Moon on the evening of December 6th. This event will be best viewed by observers in Missouri and Kansas. Where I live in southern Indiana the occultation will begin only a few minutes before the Moon sets that evening at approximately 22:36 UT (5:36 pm EST). Moonset at my location will occur only about 25 minutes later at 6pm. Binoculars or a telescope will be necessary to observe as Mars disappears behind the dark limb of the Moon. For observers in the central plains Mars’ disappearance will happen in daylight. The reappearance of the planet will occur about an hour after disappearance depending on the observer’s location. Caution! If you will be observing this event during the daylight remember to avoid pointing binoculars or a telescope at the Sun. You will sustain permanent eye damage in less than a second. The map above left shows the view to the southwest at 22:35 UT (5:35 pm EST) for an observer in southern Indiana. Click image for more information.
This chart shows where the occulation of Mars will be visible. Click on image for timings at specific locations
Geminid Meteors Peak December 14th
Many meteor watchers consider the Geminids to be the most consistent and active annual meteor shower. According to the latest Meteor Activity Outlook from the American Meteor Society : “No matter where you live, the first half of December provides some of the best meteor activity of the year. In the northern hemisphere the sporadic rates are still strong plus you can also count on strong activity from the Geminids, which peak on December 14.”
Learn more about the 2010 Geminids International Meteor Organization
Our friend Gary Winter at Celestia4all.com has produced another of his excellent animations, this one has details on the 2010 Geminid meteors
Total Lunar “Solstice” Eclipse, Monday/Tuesday December 20/21
Observers in the Americas and Pacific will have the “best seats in the house” to observe what will probably be the finest total eclipse of the Moon in years on the night of December 20/21. For observers in the eastern U.S. this will be an overnight event. For those on the west coast of North America and in the Pacific region this eclipse will be a more convenient evening event. Not only will the eclipse be spectacular for observers in the Americas and Pacific it will come only 16 hours before the winter solstice in the northern hemisphere/summer solstice in the south. Totality will last for one hour and 13 minutes. Click the image above to visit NASA’s eclipse site
The graphic to the left demonstrates event timings for the total lunar eclipse in the US Eastern Time Zone. It is courtesy of my friend Larry Koehn and his excellent website Shadow and Substance.com
Click the graphic to enlarge…and thanks Larry!
You are encouraged to report what you see during the eclipse. During every lunar eclipse the umbral shadow, the darkest part of the eclipse is about two percent larger than the geometry of the eclipse. This effect is called “enlargement of the umbra” and it varies from one eclipse to the next for reasons that are not clearly understood. This enlargement of the umbra is caused by Earth’s atmosphere. You can contribute valuable observational data by timing crater entrances and exits. For information on predicted timings of interest contact me. Learn more about this exercise here.
It is also valuable and interesting to estimate the scale of luminosity (”L”) using the Danjon scale.
I plan on observing and imaging this eclipse at a dark sky site in Indiana. If you would care to join me click the link above.









