The oldest known solar eclipse occurred 6000 years ago: The Rig Veda carries mention of it
Long before the phenomenon of the solar eclipse was scientifically identified and christened, a mention of a starkly similar event was inscribed in the Rig Veda
Amid the Rig Veda's meticulously organised Mandalas, Anuvakas, Suktas and Riks, lies mentions of potentially the earliest occurrence of what the modern scientific world identifies as a solar eclipse. Solar eclipses may not be rare but finding mention of what could have been the very first of it's kind in the annals of the Rig Veda certainly piques one's curiosity. The discovery of this mention stands credited to astronomers Mayank Vahia from the Tata Institute of Fundamental Research and Mitsuru Soma from the National Astronomical Observatory of Japan, as reported in the Journal of Astronomical History and Heritage.
Understanding what the Rig Veda carries about potentially, the first-ever solar eclipse, requires one to understand the importance of the vernal equinox in this regard. The vernal equinox marks the beginning of Spring in the Northern Hemisphere, based on the Sun's movement across the celestial equator. As per a Britannica report, "The vernal equinox, the point where the Sun's annual apparent path takes it north of the celestial equator and from which celestial longitude and right ascension are measured, lies in Pisces". Considering the fact that the Earth spins on its axis, the location of the vernal equinox also shifts over the ages. For instance, back in 4500 BC, it was on Orion while in 2230 BC it was in the Pleiades. Thus, based on the positioning of the vernal equinox, an estimated time period for the solar eclipse can be determined.
To be clear, the Rig Veda does not mention the phenomenon by name, at hand. The explanation treads symbolic waters, speaking about the sun being pierced by darkness which led to its "magic arts" vanishing. Further specifics decoded from the Rig Veda reveal that the eclipse took place three days before the autumnal equinox in congruence with, of course, a period which Ved Vyasa lived through.
This narrows down the possible dates for one of the, if not the earliest solar eclipse, to either October 22, 4202 BC and October 19, 3811 BC.
Magnificent, isn't it?