WHILE the authenticity of witnesses remain a crucial factor in the overall Ruet-i-Hilal exercise, it is deplorable that men of science, who are capable of providing practical — and perhaps valid — solutions to the issue, are hardly, if ever, consulted by the administration and its appointed clergy.
According to Shahid Qureshi, Project Director of the newly revived Institute of Space and Planetary Astro Physics at the University of Karachi, the whole issue of moon-sighting needs a holistic review, his personal preference being a “scientifically developed lunar calendar”, making use of the tremendous advancements that have been made in astronomical sciences.
Lunar calendar, as explained by Mr Qureshi, is based on the idea of Synodic month, or the time interval between two consecutive full moons or two consecutive births of new moons. Observational studies have shown that this period is 29.530589 days due to which in mathematical lunar calendar, every alternate month consists of 30 days, while the remaining are of 29 days each. So a lunar year contains 354 days.
Like Gregorian calendar, the lunar calendar also has the leap years. In a cycle of 30 years, 11 years are leap ones comprising of 355 days, adding one day to the last month of 29 days in the year. Retrospectively, the technical Islamic Hijra calendar began on July 16, 622AD (01 Moharram, Hijra 01) though it was adopted in the period of Caliph Umar in 639AD. If the empirical evidence is relied upon from this epoch, accurate mathematical calculations can lead to the formulation of a lunar calendar with suitable in-built mechanism for improvement.
Even otherwise, scientific wisdom can be of tremendous help. Several factors need to be accounted for. First, the phase of the moon is the proportion of the moon’s illuminated part to the full disc of the moon. Experts point out that the crescent moon with a phase value of one per cent and more can be physically sighted with optimum atmospheric conditions.
The second factor is the elongation, that is separation between the sun and the moon in the sky. Experts have found that a minimum 11.5 degree elongation can give rise to a phase of one per cent and more.
The third factor is the age of the moon. It is defined as the time elapsed since the birth of the new moon and its sighting. A minimum of 18 hours and 24 minutes must be the age of the moon before it becomes visible.
One very important factor affecting actual moon-sighting is the altitude of the crescent moon above the horizon at the time of sunset. Even if all other factors are well suited, the moon may not be visible if its altitude is very low at sunset, and this altitude varies greatly from place to place around the globe with changes in the latitude of the place. Usually if the altitude of the crescent moon is less than 08 degrees, its visibility can be impossible at least without any support of properly calibrated and installed telescope. This factor is greatly affected by the latitude of the place and is the major cause of the ambiguity.
Observational conditions and experience are also vital aspects. The proper locationing of the crescent can be done by the scientists possessing proper skills and, of course, proper equipment. The Institute of Space and Planetary Astrophysics is planning to acquire the latest computer-controlled equipment for the purpose, says Mr Qureshi.
Some of the other research institutions, such as SUPARCO, may be consulted which would further facilitate the task of mapping the exact position of the crescent. “The acquisition of knowledge is a compulsory pursuit in Islam,” says Mr Qureshi, and wonders why we are hesitant, if not reluctant, to move in that direction.
