Friday, January 4, 2013

The rising moon

Many of us enjoy the sight of a sunset or sunrise, but only a few ever observe the actual rise or set of the moon. There are several reasons for this. First, while most people can estimate the time of the sunset or sunrise, the time for the moonrise and moonset are not very well known and also they change dramatically every day. In addition, sunsets can be seen everyday, but seeing the moon rise or set is best when it is full or almost full, which is only 3-4 days in a month.
Rising moon
Rising moon

In order to observe the moon rise, you will need to find out two parameters: when and where. I usually use the heavens-above site (as mentioned in the article about seeing satellites), which provides this data under the moon section. These parameters change according to the observer's location. Check out the times and the azimuth (angle) of the rising and try to get to a spot where the horizon is visible and the rising moon can be seen from its first minute. Try for a full or almost full moon and check the difference of the moon appearance in the blue or dark sky. In the photo above, the moon is very dark although it is almost a full moon. This can be seen only during the first minutes of the moon rise. Also, make sure to notice the large and orange moon. Of course, everything said about the moon rise is correct for the moon-set, so if you have a clear view to the west and not to the east, watch the moon-set.
The following video shows a very red, and a distorted moon-rise. The moon is not full, about 90% of the moon face are illuminated. The video is from 1 minute after the rise, after another five minutes the moon color changed to orange and about an hour later the moon was high enough to become white.