Astronomical Insights on the Crescent Moon of Shawwal
Expert explains the phenomenon behind the crescent's size observed following the sunset on March 30, 2025.
The Director of the International Astronomy Center, Engineer Mohammed Awda Shoukat, attributed the observed size of the crescent moon after sunset on March 30, 2025, to the lunar cycle and its alignment with the sun.
He explained that when the lunar month commences based on a proper sighting of the crescent and lasts for 30 days, the crescent appears significantly larger after sunset on the 30th day.
This increase is attributed to the moon’s average distance from the sun expanding by approximately 13 degrees each day, a movement that substantially enhances the crescent's visibility within a single day.
Awda clarified that the accuracy of the lunar month’s commencement is not solely dependent on the crescent's appearance, but rather on the successful observation of the crescent on the evening of the 29th day of the lunar month.
If the crescent's visibility is below acceptable values on that day, the following day is considered the completion of the month, leading to a relatively elevated and larger crescent.
For example, regarding the current month of Shawwal, the moon set on Saturday, March 29, only ten minutes after sunset across much of the Arab world.
This led to the majority of Islamic countries declaring that the crescent was not sighted, marking Sunday as the completion of the month.
The moon's setting time is delayed by an average of 50 minutes each day, indicating that on Sunday it would set more than an hour after sunset, making it appear larger than usual.
This observation does not indicate an error in the monthly commencement, rather the opposite, as the crescent does not appear small after the sunset of the 30th day or the first day of the new lunar month.
On March 30, the moon set 74 minutes after sunset in Riyadh, 82 minutes in Amman, 81 minutes in Cairo, and 93 minutes in Rabat.
As for the sunset on Monday, the first day of Shawwal for most Islamic countries, the crescent is anticipated to be quite large, remaining visible for over two hours post-sunset, which aligns with previous observations.
It is important to note that after sunset on the first day of the lunar month, it marks the onset of the second night of the lunar month, clarifying that the crescent observed is that corresponding to the second night rather than the first.
Thus, the size of the crescent should be proportionately large as it represents the second lunar night.
He explained that when the lunar month commences based on a proper sighting of the crescent and lasts for 30 days, the crescent appears significantly larger after sunset on the 30th day.
This increase is attributed to the moon’s average distance from the sun expanding by approximately 13 degrees each day, a movement that substantially enhances the crescent's visibility within a single day.
Awda clarified that the accuracy of the lunar month’s commencement is not solely dependent on the crescent's appearance, but rather on the successful observation of the crescent on the evening of the 29th day of the lunar month.
If the crescent's visibility is below acceptable values on that day, the following day is considered the completion of the month, leading to a relatively elevated and larger crescent.
For example, regarding the current month of Shawwal, the moon set on Saturday, March 29, only ten minutes after sunset across much of the Arab world.
This led to the majority of Islamic countries declaring that the crescent was not sighted, marking Sunday as the completion of the month.
The moon's setting time is delayed by an average of 50 minutes each day, indicating that on Sunday it would set more than an hour after sunset, making it appear larger than usual.
This observation does not indicate an error in the monthly commencement, rather the opposite, as the crescent does not appear small after the sunset of the 30th day or the first day of the new lunar month.
On March 30, the moon set 74 minutes after sunset in Riyadh, 82 minutes in Amman, 81 minutes in Cairo, and 93 minutes in Rabat.
As for the sunset on Monday, the first day of Shawwal for most Islamic countries, the crescent is anticipated to be quite large, remaining visible for over two hours post-sunset, which aligns with previous observations.
It is important to note that after sunset on the first day of the lunar month, it marks the onset of the second night of the lunar month, clarifying that the crescent observed is that corresponding to the second night rather than the first.
Thus, the size of the crescent should be proportionately large as it represents the second lunar night.
