Mini-moon 2012

A few hours from now will see the smallest full moon of 2012. Not only that, but for some, the full moon will be accompanied by a penumbral eclipse.

Since “supermoon” earlier this year, each subsequent full moon has occurred with the moon farther from Earth. With the November full moon, the moon is very close to “apogee”, the farthest point from earth in the lunar cycle. On TPE for iOS, you can see the difference in time between full moon and apogee is only a few hours (see screenshot above).

The smaller size of the full moon certainly does not prevent you taking successful photographs – yes, it is smaller, but only a little. (Read 5 Useful Numbers for Sun and Moon Photographers if you’d like to know more about the impact on relative size of the moon in your photos.)

The penumbral eclipse is not likely to be a visually dramatic phenomenon (I don’t think I’ve knowingly observed one myself previously), but will likely produce some visible shading of the moon, once it is well underway

You can find out much more about the phenomenon over on NASA’s site.

If you wondered if there is a connection between the penumbral eclipse and the moon being at apogee, you’d be correct. As I understand it, a penumbral eclipse can only occur when the moon is farther from earth – in simple terms, the penumbra of the earth is a smaller target than the umbra proper. From what I’ve read, it appears that penumbral eclipses are actually less common than partial or full eclipses of the moon.

Here in Colorado, the eclipse will be timed with the setting moon, early tomorrow morning. With some luck (and a functioning alarm clock), it may be possible to catch it over the Rockies during early civil twilight.