Astronomers have identified the oldest known reference to a total solar eclipse in the ancient Hindu text, the Rig Veda.
This finding, dating back roughly 6,000 years, sheds new light on the historical understanding of celestial events by early civilisations.
A total solar eclipse occurs when the Moon passes directly between the Earth and the Sun, completely covering the Sun's disk. This alignment causes the Moon to block the Sun's light, casting a shadow on Earth and turning day into night in the path of the eclipse.
The Rig Veda, a revered collection of hymns and sayings from various religious and philosophical schools, was compiled around 1500 BC. While many of its references are contemporary to its compilation, some passages refer to events that occurred much earlier.
Among these are descriptions of the vernal equinox's position, which allow astronomers to date certain references. Notably, the text mentions the vernal equinox occurring in the constellations of Orion and the Pleiades, corresponding to around 4500 BC and 2230 BC, respectively.
The language of the Rig Veda is highly symbolic, making it challenging to distinguish between myth and historical fact. However, astronomers Mayank Vahia from the Tata Institute of Fundamental Research in Mumbai and Mitsuru Soma from the National Astronomical Observatory of Japan believe they have uncovered references to an ancient solar eclipse.
Their findings, published in the Journal of Astronomical History and Heritage, describe the sun being "pierced" with darkness and gloom, attributed to evil beings causing the sun's "magic arts to vanish."
These passages predate the more recent Hindu mythology of Rahu and Ketu, which also explains eclipses, suggesting the Rig Veda references an earlier understanding of the phenomenon.
Further analysis allowed the astronomers to narrow down the eclipse's timing to when the vernal equinox was in Orion, occurring just three days before an autumnal equinox. This points to two possible dates: October 22, 4202 BC, and October 19, 3811 BC.
These dates precede the current record holders for the oldest eclipse mentions, such as a clay tablet from Syria and a rock carving in Ireland.
The Rig Veda's reference points to the enduring fascination with solar eclipses in antiquity and demonstrates the potential of ancient texts to enhance our understanding of historical astronomical events.
