In the Name of Allah, the Beneficent, the Merciful Announcement Concerning: The Crescent Moon of…
The office of His Eminence, the Supreme Jurist of Emulation, Sayyid al-Sistani (may Allah prolong his life)
Assalamu ʿalaykum wa raḥmatullah and our prayers are for your prolonged life and continued health
A group of believers in North America would like to inquire about that which was mentioned in Minhaj al-Salihin and other sources that “the unity of the horizons” only occurs for two lands if the sighting in the first land is associated with the sighting of the crescent in the second land, even if it was not sighted because of dust or clouds.
Based on the figure below, both as a result of contentment and experience, the areas that are in orange or dark yellow are the areas in which the crescent moon can be seen with the naked eye under ideal conditions—such as clear skies. However, in the other areas, the age of the crescent moon would be more than forty hours after its birth (as an example) and contentment in the ability to sight the crescent is attained based on the astronomical data, such as the red area on the map that depicts the areas in which the sighting was proven through tawatur (those who sighted the crescent gave the same description of the crescent and such diverse groups could not possibly conspire to lie about the matter) and through repeated experiences that there surely is an ability to sight the crescent in this area and with ease and clarity.
Based upon the criteria mentioned in Minhaj al-Salihin and based on scientific proof as well as the practical experience in the ability to sight the crescent in the red region, may we interpret the phrase in Minhaj of “the unity of horizons” to include all of the areas that are within the red region, without paying attention to the areas next to the dark yellow region in which there is neither contentment nor a great probability of sighting the crescent moon? Therefore, as an example, may we say that as long as the crescent sighting has been proven religiously in the city of Los Angeles, then it will also be sighted in the city of Miami and Ecuador as a result of the association [or relationship] between the areas in the sighting—based on experience and contentment in the astronomical data?
Please benefit us with your response, may Allah (swt) reward you.
If it is proven surely that the crescent moon in the areas that fall close to the edge of the red region are at an altitude and size close to those of the crescent in the areas after it, in which the crescent moon was indeed sighted with clarity, then contentment is usually attained that such a relationship between the two areas exists. This is contrary to the case in which it may be expected that the crescent in those areas is smaller in size or lower in altitude to the extent that it is not possible to sight the crescent moon with the naked eye, even if the astronomers made the claim that it is indeed possible.
The seal of the office of Ayatullah Sayyid ʿAli al-Sistani
The Holy City of Najaf
Rajab 8, 1429