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Mercury, May/June 1995 Table of Contents

by Imad A. Ahmad, Imad-ad-Dean, Inc.
and S. Khalid Shaukat, Nuclear Regulatory Commission

(c) 1995 Astronomical Society of the Pacific

On Mar. 2, families throughout the Muslim world joined their neighbors on rooftops and in open fields, kids sitting on their fathers' shoulders, squinting to glimpse the Moon: the fibrous young Moon that would mark the end of Ramadan.

Catching sight of the elusive first crescent is a thrill for astronomers, but has a special significance for Muslims. It marks the beginning of each Islamic month and sets the dates of religious activities, such as fasting (in the month of Ramadan), the feast to mark the end of fasting (in the month of Shawwal), and the greatest Muslim holiday, Eid-al-adha -- the feast commemorating Abraham's sacrifice, which coincides with the climax of the pilgrimage to Mecca.

In America, few Muslims go out to look for the new crescent themselves. Most immigrant Muslims are satisfied to call their native homelands for a report. This causes confusion when Muslims in America accept unconfirmed sightings by a single observer in another country, even though the majority of those searching have seen nothing. In Muslim countries, Moon-sighting takes on a cultural dimension beyond the religious and scientific.

One of us, born and raised in a Muslim country, cherishes childhood memories of joining the crowds competing to catch the first sight of the thin crescent after sunset on the 29th day of Ramadan. If we could see it, the next day would be Eid-al-Fitr, the ``Feast of Breaking Fast.'' If we did not see it, fasting would continue one more day. My father would take us to join the neighbors on some open field and relatively high ground shortly after sunset. We focused on the western horizon, our hearts full of excitement and hope, to see the crescent that would herald the day of receiving gifts, getting money from elders, and eating delicious food after having fasted every day for the whole month. Sometimes my father would lift me up on his shoulders in order to show me the crescent. Someone would shout, ``There it is!'' breaking the news to everyone. All night long, we could not sleep, making preparations for tomorrow's happy occasion. Some people would even go shopping at the last minute.

This year, most American Muslims began fasting on Feb. 1, 1995. Thus, the day to start looking for the Moon of the Eid festival was Wednesday, Mar. 1. We knew that we could not see this new Moon in Washington, D.C. that night. It was cloudy, but even if it had been clear, the Moon, less than 6 degrees away from the Sun, would have been hidden by the "Danjon Effect" -- shadows on the rough lunar surface shorten the crescent, and when the Sun and Moon are closer than 6 degrees, the crescent is shortened into nothingness.

Nor did we expect any valid sightings from the West Coast, where the Moon would be setting while the evening sky was still brighter than the lunar surface. We were concerned about an article in Astronomy magazine in March, which ambiguously called the possibility of a West Coast sighting "slim." This might have sparked dubious reports from unskilled observers confusing condensation trails or other objects with the crescent. As it happened, two false sightings were reported, from Detroit and from Allentown, Pa. In both cases, the location of the object reported did not match the Moon's location, confirming the theoretical grounds for rejecting the reports.

We received many negative sighting reports: phone calls confirming that Moon was not sighted by the hundreds of people who tried to see it on clear skies from New York to Oregon. One tantalizing report from Seattle had to be rejected because the reported crescent was misaligned with the Sun. There was even a negative report from a Muslim observer in Hawaii who seeks the new Moon every month but could not see it this time, despite the clear horizon.

On Mar. 2, Mudassir Siddiqi called from India reporting to have seen it. His niece was the first to spot the slender crescent, and when she called out the entire family rushed to the roof. All could see it. Later that day the thin crescent was seen by a reliable source in Jeddah, Saudi Arabia. Several hours later, when the Sun set on the East Coast of North America, the Moon, now grown fatter, was easy to see -- so much so that some Muslims found it hard to believe that the Moon could not be seen the night before. But this rapid growth of the crescent was well known to Muhammad, as is related in the following hadith (tradition) in the Sahih Muslim:

We are told that Abu'l-Bakhtari took a dispute about whether a large New Moon was truly new or one or two days old to the Prophet's companion Ibn Abbas who quoted the Prophet Muhammad as having said of the invisibility of young New Moons: "Verily God deferred it till the time it is seen, so it is to be reckoned from the night you saw it."

IMAD-AD-DEAN AHMAD is president of Imad-ad-Dean, Inc., an astronomy research firm in Bethesda, Md. He was chair of the 1987 Lunar Calendar Conference in Herndon, Va. and editor of its proceedings. He is the author of A Uniform Islamic Calendar for the Western Hemisphere. His email address is

SYED KHALID SHAUKAT is a research scientist at the Nuclear Regulatory Commission in Washington, D.C. He is a consultant to the Islamic Society of North America and the Fiqh Council of North America on the Moon-sighting, and an advisor to the Greater Washington Muslim Communities and Mosques for making decisions on the beginning of Ramadan, Eid-al-Fitr, and Eid-al-Adha.

Illustration captions

The crescent Moon, 26 hours after New Moon. Peter Ledlie took this photo from the Sunset Point Rest Area near Phoenix, Ariz. in April 1994, about a half-hour after sunset. It is a 1 second exposure with a 4-inch StarFire refractor. Because the young Moon is tough to spot with the naked eye, Ledlie used the Voyager II desktop planetarium program (available from the ASP Catalog) to know when and where to look.

Geometry of the crescent Moon shown in the photo. By 26 hours after New Moon, the Moon had moved just enough around in its orbit that part of the illuminated hemisphere was visible from Earth (see arrow). The record for spotting the crescent is about 13 hours after New Moon. Any earlier, and the crescent is so thin and dim that it gets washed out in the twilight glare.


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