Shawwal crescent too faint to be seen even with telescopes - JAS

AMMAN — The Jordanian Astronomical Society (JAS) said on Wednesday that astronomical calculations show it would be "impossible" to sight the Shawwal crescent for the year 1446 AH after sunset on Saturday, March 29, in Jordan and across the Islamic world, whether with the naked eye or telescopes. 

Despite the crescent being above the horizon after sunset, it will be too faint to observe, the JAS added, according to Al Rai Newspaper.

JAS President Ammar Sakaji explained that the crescent will be exceedingly thin and faint, making it invisible even with telescopes. Astronomical calculations indicate that the crescent will remain above the horizon for varying lengths of time in Arab capitals: 11 minutes in Cairo, 10 minutes in Jerusalem, 7 minutes in Mecca, and 18 minutes in Marrakesh.

Sakaji emphasised that the JAS does not have the authority to announce the dates for Islamic holidays or religious observances, adding that the responsibility for determining the start of Hijri months lies with the Grand Mufti of Jordan and the Iftaa Department, Research, and Islamic Studies, which serve as the official sources on such matters.

He also reiterated that the impossibility of sighting the crescent is based on internationally recognised astronomical criteria, including the Babylonian, Al Battani, Ilyas, Schaefer, Danjon, Yallop, Alawi, and Odeh criteria. 

Sakaji also noted that various astronomical and physical factors, such as atmospheric distortion and turbulence caused by dense air masses, contribute to the crescent’s faintness. Additionally, light scattering and absorption, particularly from short-wavelength light, further hinder visibility.

Sakaji added that large ground-based telescopes face challenges in observing the crescent due to technical limitations, such as tracking objects close to the horizon, and the fact that these telescopes are not designed for such observations. 

He proposed that one solution to improve crescent sighting in the future could be the development of specialised solar telescopes, similar to the Solar and Heliospheric Observatory (SOHO), which uses advanced techniques like a coronagraph to block sunlight and reveal celestial objects near the sun.

Sakaji highlighted that technological advancements, including artificial intelligence for predictive modeling and the expansion of both ground-based and space-based solar telescopes, could improve the accuracy and effectiveness of crescent observation in the future.