SUNSET: 
0After sunset on New Year's Day, skilled telescope or binocular observers in the western three-quarters of North America may be able to spot a nearly world-record-thin young Moon.
An older thin crescent. On October 26, 2003, after taking his camera to Pescadero State Beach in California, Youssef M. Ismail caught this 37-hour-old Moon with Venus to its right.
Courtesy Youssef M. Ismail
Shortly after sunset on January 1st, many North Americans can try to spot what's likely to be their personal record for a young crescent Moon. An extremely thin trace of the Moon will be almost straight above the sunset point and, conveniently, 8° or 9° lower right of Venus. Moreover, the Moon is at perigee.
The sighting will probably be impossible from the East Coast, where the Moon will be just 11 hours old and 7° from the Sun a half hour after sunset. But it may be possible with a telescope in the Central time zone and with binoculars near the West Coast, where the Moon will be approximately 14 hours old and 8.5° from the Sun. Calculate its age from the time of new Moon, which happens at 11:14 Universal Time (3:14 a.m. Pacific Standard Time) January 1st.
Go out early to mark the spot where the Sun sets, set up your gear, and start watching no more than 15 minutes after sundown. Keep watching for another 25 minutes to catch your time of best visibility, which will depend on your location and the sky conditions. If you see the Moon with optical aid, try with the naked eye.
To read more about the pursuit of young Moons, see skyandtelescope.com/youngmoon.
About Alan MacRobert
Alan M. MacRobert became an avid Sky & Telescope subscriber in 1966 at age 14, joined the editorial staff in 1982, and is now a senior contributing editor, semi-retired. He played a role in practically every part of the magazine and the company's other products for more than a generation, both on the amateur-observing side and the science-reporting side. In 1994 a book collection of his observing how-tos and telescopic sky tours was published as Star Hopping for Backyard Astronomers. He has produced This Week's Sky at a Glance online every week since 1989.
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