Personal Observation and Motivation: Reflecting on the Crescent of 26 February 632 CE and the Farewell Pilgrimage of Prophet Muhammad ﷺ

As a Muslim, I have been observing the crescent moon since childhood. What began as a simple act of tradition gradually developed into something much deeper. Over time, it passed through many stages—most of which were periods of standing behind elders whilst they were searching the moon, excitement, and religious attachment—but eventually curiosity increased, going further began to have a scientific approach, and a serious commitment followed. In recent years, my focus has shifted towards the study of lunar visibility, which requires patience, repeated observation, and attention to fine detail.

During this journey, I recall discussing the crescent associated with the Farewell Pilgrimage (Hajjat-ul-Wadaa) with a colleague in 2021. By this stage, I had already begun approaching moon sighting from a more analytical perspective. When I first examined the likely moon’s parameters at the sunset of 26 February 632 CE, I was genuinely surprised. The moon was only 0.60% illuminated, with an altitude of approximately 7.11°. And of course, I implied that a crescent must have been observed to the naked eye only, as binoculars and telescopes were not available at the time.

Over the years, my chase of crescent observation has been driven by different motivations. More recently, the study of lunar visibility—through data, observation, and comparison—has become a key focus. This has encouraged me to actively seek out difficult and challenging crescents. It is not something I intend to pursue indefinitely, but rather a focused effort to explore specific questions and curiosities within my research.

At the time, I had only just begun to successfully observe very difficult crescents. Yet the crescent moon of 26 February 632 CE remained in my mind at every time, also because it was directly linked to the Farewell Pilgrimage (Hajjat-ul-Wadaa). It stayed with me quietly, in the background, as something I wanted to attempt to observe myself. I began examining future dates and realised that such opportunities are rare.

The first real opportunity came on 8 May 2024. I remember the anticipation clearly. After considering multiple locations abroad, I decided to remain in the UK. I spent the entire day travelling from Bolton in search of a clear western horizon, accompanied by a witness. By sunset, I had reached Reculver, Margate, UK (Illumination: 0.59%, Lag: 67 minutes, Altitude: 7.39°, Elongation: 8.76°, Age: 16:08:09). However, the sky remained fully clouded. The horizon never cleared, and the crescent was not visible. I had to report a negative sighting. https://www.facebook.com/share/p/1CXBMVXtJG/

After seriously waiting for three years, not even being able to properly attempt the observation was deeply upsetting. The effort, the expectation, and then not being able to execute anything—it is difficult to describe that feeling. Yet, moments like this test patience, and I knew I had to continue. I set my focus on the next opportunity.

That opportunity would not come quickly. I knew that 19 March 2026 would offer similar conditions, but it required waiting through 22 lunar months, with no guarantee of success. Weather uncertainty always remains—you can prepare everything and still lose the moment to bad conditions on the horizon.

Then, by the will of Allah, I found myself in Devon, UK. This time, the horizon remained clear enough. Using binoculars and a telescope, we observed the crescent for approximately 28 minutes, uninterrupted and continuously visible. Sharing the sighting with four others made the moment even more meaningful.

Yet, even in that success, there remained a quiet sense of incompleteness.

I still remember the first moment I saw it through the telescope. It appeared as a faint, delicate arc—so thin it almost seemed unreal. For initially some minutes, it looked like a broken line of light. Then it reminded me of a sharp blade catching sunlight—fine, bright, and incredibly precise, but it was unevenly illuminated, remember screaming as observing, wow, it looks like a broken arc, split moon. As the minutes passed, the crescent became clearer, extending, gaining form and was seen easily without any effort, but thin.

That evening, I did not manage a proper naked-eye attempt at the right moment. I was occupied—helping others see it, trying to capture it in photographs, unsure whether any image would even come out. In that moment, documentation and sharing took priority. But later, I realised I had missed the chance I had been quietly hoping for.

The Prophet ﷺ and his companions would have observed such a thin crescent without optical aid, as instruments like binoculars and telescopes were not available. In my case, the crescent was observed only with binoculars and a telescope. Notably, the moon on 26 February 632 CE (0.60% illumination) had an altitude of approximately 7.20°, -0.43° lower than mine in Devon alt at sunset, the 7.63° (0.58% illumination), yet I was still unable to observe it with the naked eye.

If these calculated numerical parameters align correctly with the sunset of 26 Feb 632, then observing such a thin crescent at a relatively low altitude with the naked eye would be remarkable.

As someone deeply engaged in lunar visibility, I find this an open question in my study, leaving a lingering desire to one day witness such a delicate crescent unaided and better understand that experience.

It is also worth reflecting on whether environmental conditions over the past 1400 years may have differed from those we experience today. Could the atmosphere have been clearer, allowing for better visibility? To what extent human activity and development have influenced changes in climate, atmospheric composition, and horizon clarity is difficult to say. It remains an open question.

And so, the pursuit continues. The challenge, however, is that the next opportunity for a very similar crescent in the UK will come after many years. Whether I will still be actively observing by then is uncertain—but In Sha Allah, I hope I will be.