The Moon does not produce its own light
This is the one most people assume was figured out recently. Aryabhata stated it plainly in the Aryabhatiya, written in 499 CE: the Moon and planets shine because they reflect sunlight. Brahmagupta repeated and elaborated on this in the Brahmasphutasiddhanta in 628 CE. European astronomy held onto the idea of the Moon as a luminous body well into the medieval period. The reflected-light explanation that Indian astronomers had committed to text took centuries longer to settle in the West.
Solar and lunar eclipses are caused by shadows, not demons
The Rahu-Ketu mythology, the severed head and tail of a demon swallowing the Sun and Moon, is one of the most vivid astronomical stories in any culture. Aryabhata knew it was a story. In the Aryabhatiya, he gave a geometric explanation: a lunar eclipse occurs when the Moon enters Earth's shadow; a solar eclipse occurs when the Moon's shadow falls on Earth. He calculated the sizes of these shadows. This was not a rejection of the mythology as such, it was an astronomer doing astronomy. The two things existed in parallel, and Aryabhata was unambiguous about which was the physical mechanism.
The Moon's orbital period, calculated to within minutes
Aryabhata calculated the Moon's sidereal period, the time it takes to complete one orbit relative to the stars, as approximately 27 days, 20 hours, and 24 minutes. The modern measured value is 27 days, 7 hours, and 43 minutes. That is a difference of a few minutes across a calculation made without instruments that could measure arc-seconds. The Surya Siddhanta, an astronomical text whose core dates to roughly the 4th or 5th century CE, also contains detailed lunar period calculations that later astronomers refined. The precision is not a coincidence of lucky guessing, it comes from systematic, long-term observation recorded across generations.
The Moon's distance from Earth
Aryabhata estimated the Moon's mean distance from Earth at approximately 62,832 yojanas. The yojana is not a fixed unit, its length varied by region and period, but working with the most commonly used conversion of roughly 8 kilometres per yojana gives a figure in the range of 500,000 kilometres. The actual mean lunar distance is about 384,400 kilometres. The estimate is not exact, and the unit conversion introduces real uncertainty. What matters is the method: Aryabhata derived this from geometric calculation using the Moon's angular diameter and observed parallax, the same class of method modern astronomy uses. The approach was right even where the number was approximate.
The Moon causes the tides
The connection between the Moon and ocean tides appears in Indian astronomical and geographical literature well before Newton formalised gravitational theory in the Principia Mathematica in 1687. The Surya Siddhanta references lunar influence on water. Varahamihira, writing in the 6th century CE, discussed the Moon's effect on living things and bodies of water in the Brihat Samhita. The mechanism, gravity, was not named or mathematically described in these texts the way Newton described it. But the observation that the Moon pulls the tides, and that this pull follows the lunar cycle, was documented. Newton provided the why. Indian astronomers had already recorded the what.
The Moon's axial rotation matches its orbital period
The Moon rotates on its axis in exactly the same time it takes to orbit Earth, which is why we always see the same face. This is called synchronous rotation, and it is the result of tidal locking over billions of years. Ancient Indian astronomical texts noted that the Moon presents one face to Earth permanently, the Chandramukha, the Moon-face, is always the same face. The observation was correct. The physical explanation for why this happens, tidal forces gradually slowing the Moon's rotation until it matched its orbital period, came much later. The fact was recorded. The mechanism waited for orbital mechanics to catch up.
The Moon moves through a fixed set of lunar mansions
The Nakshatra system divides the Moon's path through the sky into 27 (sometimes 28) segments, each corresponding to a day of the sidereal lunar month. This is not mythology dressed as astronomy, it is a coordinate system. Each Nakshatra marks a specific region of the sky defined by a prominent star or asterism. The Moon's position could be tracked and predicted by knowing which Nakshatra it occupied on a given night. Vedanga Jyotisha, one of the oldest Indian astronomical texts, uses this system for calendar calculations. Modern astronomy uses a different coordinate system, but the underlying observation, that the Moon follows a consistent, predictable path through identifiable star fields, is the same fact, mapped with different tools. The Nakshatra system was a working lunar almanac that Indian farmers, priests, and navigators used for centuries before the telescope existed.
What these seven facts share is not mysticism but method. Aryabhata and the astronomers who followed him were solving specific problems, predicting eclipses, fixing calendars, calculating positions, and they recorded what they found. The confirmation that came later from telescopes, orbital mechanics, and space missions did not discover these facts for the first time. It arrived at the same place by a different road.
