In Jainism, the most important part of “astronomy” is not planets and stars like modern science, but how the whole universe (loka) is structured for the journey of the soul.

In very simple terms, the key ideas are:

1. The universe (loka) is eternal, not created by any God

- No beginning, no end. - It always existed and always will. - It runs by its own natural laws and karma of jivas (souls).

1. Three main regions – this is central to Jain cosmology

- Urdhva Loka – upper world, where celestial beings (devas) live. - Madhya Loka – middle world, where humans, animals, plants live; only here liberation (moksha) is possible. - Adho Loka – lower world, where hellish beings (narakis) suffer due to bad karma.

1. Shape and structure of the cosmos are fixed and precise

- The whole loka is described like a cosmic man (lokapurusha): broad at top and bottom, narrow in the middle. - In the middle, there is Jambudvipa with Mount Meru at the center – this is the “earth region” in Jain cosmology.

1. Siddha-shila – the highest, most important point

- At the very top of the universe is Siddha-shila, where liberated souls (Siddhas) stay forever. - This is beyond birth, death, pleasure, pain – only pure, infinite knowledge and bliss.

1. Six eternal substances (dravya) – special to Jain view of the universe

Among them, two are very “astronomical” in nature: - Dharmastikaya – the medium that allows movement. - Adharmastikaya – the medium that allows rest. Together with Akash (space), Kala (time), Jiva (soul), and Pudgala (matter), they explain how the universe works without a creator.

1. Time is cyclical, not linear

- Cosmic time moves in endless cycles of Utsarpini (ascending happiness) and Avasarpini (descending happiness). - Tirthankars appear in fixed patterns within these cycles.

1. Spiritual purpose is the main focus

- All these details of heavens, hells, continents, directions, etc., are not for curiosity but to show: - how karma moves the soul up or down, - why human birth is precious, - and how to reach Siddha-shila by right faith, right knowledge, and right conduct.

Digambar and Shvetambar: Both accept this same basic structure: three worlds, Siddha-shila on top, Jambudvipa in the middle, six dravyas, and cyclical time. They differ only in some measurements, diagrams, and minor details, not in the core ideas.

So, the most important part of Jain astronomy is: Understanding the fixed, eternal structure of the universe (trilok) as the stage on which the soul travels through birth and rebirth, and finally rises to Siddha-shila through self-purification.