Eclipses of the Sun and Moon according to Jaina Astronomy
By J. C. Sikdar
Summary
J. C. Sikdar’s article surveys the treatment of eclipses in Jain astronomy and compares it with other Indian astronomical schools and modern science. Drawing on Jaina Āgamas and post‑Agamic texts such as the Sūrya‑prajñapti, Candra‑prajñapti and Br̥hat Saṃgrahaṇī, Sikdar explains that Jain cosmology situates the Earth and celestial bodies within concentric cosmic zones and describes the motions of the Sun, Moon and planets in terms distinct from Brahmanical models. The article outlines two popular ancient Indian explanations for eclipses: one attributing them to the demon Rāhu capturing the Sun or Moon, and another attributing them to various kinds of black matter that follow and shade the luminaries. Jain teachers rejected both views, proposing instead that eclipses occur when Parva Rāhu—conceived not as a demon but as a celestial entity with dark rays—passes between the Earth and the Sun or Moon, partially or totally obscuring their light. Sikdar details how Jain texts describe the mechanics of partial and total lunar and solar eclipses, the frequency and recurrence of eclipses (including the saros cycle), and associated phenomena such as changes in the apparent brightness of the Moon during an eclipse. The article also summarises prescriptions found in works like the Sūrya‑prajñapti on calculating eclipse timings based on the positions of celestial bodies and black matter. Sikdar then compares Jain explanations with those of other Indian schools—such as those of Āryabhaṭa and the Sūrya‑siddhānta—and notes that while modern astronomy correctly attributes eclipses to the alignment of the Earth, Moon and Sun, Jain scholars used observational reasoning to derive analogous conclusions about perceptibility and sequence. The essay concludes that despite differences in cosmological assumptions, Jain astronomers made earnest efforts to explain eclipses using the conceptual frameworks available to them and that their discussions were both descriptive and prescriptive, addressing ritual observances and interpretations of eclipses’ effects on Earth. By juxtaposing ancient Jain views with modern science, Sikdar invites readers to appreciate the historical development of astronomical thought in India.
Conclusion
Sikdar concludes that Jain astronomers, operating within their distinct cosmology, offered a coherent explanation for eclipses that differs from but parallels other ancient and modern theories. By conceptualising Parva Rāhu as a celestial entity whose dark rays obscure the luminaries, they accounted for the occurrence, duration and recurrence of lunar and solar eclipses. Although their models lack the precise geometrical understanding of modern astronomy, the author emphasises that Jain scholars investigated celestial phenomena systematically and contributed to India’s diverse astronomical heritage. The study underscores the value of comparing traditional scientific perspectives to better appreciate the evolution of astronomical knowledge.