Determining the beginning of the Hijri month through the sighting of the new moon is very important for Muslims because it relates to the time of worship, especially the months of Ramadan, Shawwal and Zulhijah. This is how the new moon looks like and how to see it.
The calculation of the Hijri month used by Muslims is based on the regularity of the Moon's circulation around the Earth, and the Earth with the Moon in revolving around the Sun.
Hilal shape
The new moon is the crescent moon that is seen for the first time right after the new moon phase. The condition for the crescent moon that can be said to be the new moon is if it can be seen after sunset.
The original hilal is a crescent moon shaped like the letter U with a position facing the sun. This is in accordance with the Arabic term, hilal means crescent moon.
Another understanding of the new moon that explains its shape is the appearance of the crescent moon which is the earliest seen from Earth after conjunction / Ijtima 'and sunset. Conjunction itself is an event when the ecliptic longitudes of the Moon and the Sun are the same, with the observer assuming that it is at the center of the Earth. While the setting of the Sun is an event when the top of the disk of the Sun or Moon is right on the Horizon-observed.
The age of the moon that astronomers usually observe is less than 12 hours and its height is still below 6 degrees from the horizon. With such a height, the hilal will set approximately 24 minutes after sunset.
Astronomical Objects That Can Disrupt the Rukyat Hilal
Finding and seeing the new moon is not easy. The thin shape of the hilal, as well as a very narrow opportunity or time span, make it only visible to skilled people. In addition, there are also other astronomical objects that can disrupt the rukyat hilal.
Therefore, in planning the rukyat of the new moon, it is also necessary to estimate astronomical objects other than the new moon and the sun which are in close proximity to the moon, and whose brightness does not differ much from the new moon or is brighter than the new moon.
This astronomical object can be a planet, such as Venus or Mercury, or a bright star, such as Sirius. The existence of other astronomical objects has the potential to make observers perceive it as the new moon when in fact it is not.
Based on forecasts, on May 1, 2022, from the time the sun sets until the moon sets, there will be no other astronomical object whose angular distance is less than 10° compared to the moon.
How to See the Hilal
To make it easier to find and see the new moon, rukyat experts use tools such as telescopes and highly sensitive CCD cameras. With such an arrangement, they can see a very thin and low hilal.
In addition, with the current sophistication of technology, the calculation of the position of the new moon can be determined.
To determine the beginning of the month of Shawwal 1443 H by taking into account the time of conjunction and sunset, conjunctions occur before sunset on May 1, 2022.
As previously mentioned, observing the new moon is very important as a sign that the beginning of the new month in the Hijri calendar has begun. If the new moon has not been seen, then it has not changed months in the Hijri calendar. After observing the new moon, it means that the night has entered the beginning of the new moon. If it is the first hilal of Shawwal, then all Ramadan worship activities will end, and Muslims celebrate Eid al-Fitr.