Tag: Moon

At sunset this evening the Moon will be less than a day past new, about 20 hours old and only 0.7% illuminated. It is possible, if somewhat challenging, to spot this very thin crescent in the evening sky deep in the bright glow of sunset.

This evening the Sun will set at 18:39 and the Moon will set at 19:21, about ten degrees behind the Sun. Thus a low and clear western horizon is a necessity for locating the Moon tonight. Optical aid will also be very useful, once the correct area is located the Moon can often easily be found by sweeping the area with binoculars. A small, rich field telescope with a field of several degrees across can also be used.

The effort is aided a bit by the presence of the bright planet Mercury in the sunset this evening. The planet will be seven degrees higher in the sky and just a bit north of the Moon. If you find Mercury at 19:00HST, the Moon will be 5 degrees below the planet and four degrees to the south in azimuth.

In several cultures with lunar calendars the spotting of a young crescent Moon like this marks the beginning of the month. Often Moon sightings are used to determine religious holidays and other important events of the year. It is also an good challenge to practice your observational skills. have fun!