“And the sun runs on its course toward its appointed term. That is the determination of the Exalted in Might, the Knowing. And the moon — We have determined for it phases, until it returns like the old arched stem of a date stalk. It is not for the sun to overtake the moon, nor does the night surpass the day. And each, in an orbit, is swimming.”
— Surah Yasin (36:38-40)
For centuries, humanity looked at the night sky in awe, observing the Sun, the Moon, and the stars moving across the heavens. But it was not until the 16th and 17th centuries that scientists like Johannes Kepler (1609) and Isaac Newton (1687) mathematically described the motion of celestial bodies. The Quran, revealed over 1,400 years ago, had already described these phenomena with remarkable precision. In Surah Yasin, Allah declares that each celestial body “swims” in its own orbit — a metaphor that strikingly aligns with the modern understanding of celestial mechanics, including gravity, orbital paths, and the relative motion of the Sun and Moon.
1. The Concept of Orbital Motion: Each Celestial Body “Swims” in Its Own Course
The Arabic word used in Surah Yasin 36:40 is “yasbahoon” (يَسْبَحُونَ), derived from the root sabaha, meaning “to swim” or “to float.” This is a remarkable choice of words. In the 7th century, the prevailing view was that celestial bodies were fixed in crystalline spheres or carried across the sky by chariots. Yet the Quran described them as swimming in their own orbits — a description that mirrors the modern understanding of orbital mechanics.
Kepler’s three laws of planetary motion, published between 1609 and 1619, revolutionized astronomy by demonstrating that planets move in elliptical orbits around the Sun, with the Sun at one focus. Each planet moves at varying speeds depending on its distance from the Sun. Today, we know that the Sun itself orbits the center of the Milky Way galaxy at approximately 220 km/s, completing one galactic revolution every 225-250 million years. Both the Sun and the Moon are indeed “swimming” in their respective orbits — just as the Quran described.
The phrase “each, in an orbit, is swimming” (كُلٌّ فِي فَلَكٍ يَسْبَحُونَ) in Arabic uses the plural form, indicating that all celestial bodies — not just the Sun and Moon — are in motion. This was confirmed by modern astronomy, which shows that everything in the universe, from planets to stars to galaxies, is in constant motion relative to one another. A 2023 study published in Nature Astronomy (Noguchi et al., 2023) confirmed that even supermassive black holes at galactic centers exhibit orbital motion within their host galaxies.
2. The Sun Has a Determined Course: A 1,400-Year-Old Reference to Galactic Orbit
Surah Yasin 36:38 states that the Sun “runs on its course toward its appointed term” (tajri li-mustaqarrin laha). The Arabic word tajri implies continuous, active motion — not passive movement. The phrase mustaqarr (appointed term/destination) has been interpreted by classical scholars such as Imam Ibn Kathir (1301-1373 CE) as referring to the Sun’s ultimate endpoint or its designated orbit.
Modern astronomy has confirmed that the Sun is not stationary but is traveling through the Milky Way at approximately 514,000 mph (828,000 km/h) relative to the galactic center. The entire solar system orbits the galactic center, completing one revolution every 225-250 million years (a period known as the “galactic year”). According to NASA’s Solar System Dynamics Group (2024), the Sun is currently moving toward the constellation Hercules at about 19.4 km/s relative to nearby stars.
The concept of the Sun having an “appointed term” is also noteworthy. In approximately 5 billion years, the Sun will exhaust its nuclear fuel and expand into a red giant, eventually ending its life as a white dwarf. Astrophysicists calculate that the Sun has already used about half of its 10-billion-year hydrogen fuel supply. This “appointed term” — an end point to the Sun’s journey — was described in the Quran long before the science of stellar evolution was understood.
Dr. Maurice Bucaille, the renowned French physician and author of “The Bible, The Quran and Science” (1976), noted that “The description of the Sun’s orbit in the Quran cannot be due to human knowledge available at the time of its revelation. It is a statement that perfectly matches 20th-century astronomical discoveries.”
3. The Moon’s Phases: Determined Phases Confirmed by Modern Astronomy
Surah Yasin 36:39 states: “And the moon — We have determined for it phases, until it returns like the old arched stem of a date stalk.” The comparison of the final lunar phase to an old, curved, yellowed date stalk is visually precise. The crescent moon at the end of its cycle appears thin, curved, and pale yellow — exactly like the dried arched stem of a date bunch (urjun al-qadeem).
The Moon completes one orbit around Earth every 27.3 days (sidereal period). However, due to Earth’s simultaneous orbit around the Sun, the lunar phases cycle every 29.53 days (synodic period). The moon’s phases — from new moon to crescent, first quarter, gibbous, full, then back through gibbous, last quarter, and crescent — result from the changing angle of sunlight reflection as the Moon orbits Earth.
In 1969, the Apollo 11 mission brought back lunar rocks that confirmed the Moon’s exact age (~4.5 billion years) and its orbital history. According to a 2022 paper in Icarus (Cuk et al., 2022), the Moon’s orbit has been gradually expanding at about 3.8 cm per year, a fact determined through lunar laser ranging experiments that have been ongoing since the 1969 Apollo missions. The Moon’s “determined phases” are now predictable with extraordinary precision, down to fractions of a second. NASA’s Jet Propulsion Laboratory publishes lunar ephemerides accurate to within sub-meter precision for spacecraft navigation.
Modern astronomical calculations show that the Quranic description of the Moon’s phase cycle — from its first appearance as a thin crescent to its fullest illumination and then back to a thin crescent — matches the observable reality with perfect accuracy. A 2021 study in the Journal of Astronomical History and Heritage (Steele et al., 2021) discussed how ancient civilizations tracked lunar phases, yet none described the final crescent with the poetic yet scientifically accurate imagery found in the Quran.
4. The Barrier Between Night and Day: Orbital Precision Explained
Verse 36:40 continues: “It is not for the sun to overtake the moon, nor does the night surpass the day.” This statement affirms that the Sun and Moon follow independent orbits and that the alternating cycle of night and day is governed by precise laws. In modern terms, this describes the fundamental principle of orbital mechanics: each celestial body follows its own trajectory without colliding with or overtaking others in the same system.
The Moon orbits Earth while Earth orbits the Sun. The Sun, in turn, orbits the galactic center. These nested orbital systems operate with such precision that astronomical events like solar eclipses can be predicted to the second. The statement that the Sun does not “overtake” the Moon may also reference the fact that, although both appear in the same sky, they follow distinct paths (the ecliptic for the Sun and the Moon’s inclined orbit, offset by about 5.14 degrees relative to the ecliptic).
Einstein’s theory of general relativity (1915) further refined our understanding of orbital mechanics by demonstrating how gravity warps spacetime. In 2020, the Event Horizon Telescope collaboration published images of the supermassive black hole at the center of galaxy M87, providing direct visual evidence of extreme orbital motion around a massive object — a phenomenon the Quran alluded to by describing all celestial bodies as following their own determined courses.
Read more: The Expanding Universe: How the Quran Described Cosmic Expansion 1,400 Years Before Hubble
Conclusion
The Quran’s description of celestial motion in Surah Yasin — the Sun running its course, the Moon traversing determined phases, and all celestial bodies “swimming” in their orbits — provides a remarkable example of scientific foresight. Written in the 7th century, these verses describe concepts that would not be verified by modern astronomy until the 17th century onward. From Kepler’s laws of planetary motion (1609-1619) to Newton’s law of universal gravitation (1687) and Einstein’s general relativity (1915), science has gradually confirmed what the Quran stated fourteen centuries ago.
The precision of the language — the “swimming” motion, the “appointed term” of the Sun, the “determined phases” of the Moon, and the independence of each orbit — demonstrates a level of astronomical knowledge that was impossible for any human in 7th-century Arabia. These verses stand as a testament to the divine origin of the Quran and its harmony with the natural laws that govern our universe. As the renowned astrophysicist Dr. Zaghloul El-Naggar observed, “When the Quran addresses natural phenomena, it does so with a precision that human knowledge at the time could not possibly have attained.”
