Cosmology is not astronomy!

Astronomy and Astrology (which is generally considered a 'pseudo-science' in Western academia) is used to calculate movable feasts and Holy Days in religions such as Christianity, Islam, Hinduism, Vaishnavism, etc.  

Old observatories located in Greenwich, Baghdad, Ujjain, and even Beijing were and still are used to monitor the movements of heavenly bodies, continuously making minor adjustments to their astronomical and astrological tables and refining the methods of calculating and predicting such movements.

In ancient ages planets moved at different speeds to the present time and continue to change velocity over extended periods. Even in our relatively short lifetimes, perceptible errors are recorded – as for instance, over decades the Earth's orbit varies and doesn't always concur to expected movement! Hence the need for observatories.

Puranic or Vedic Cosmology is a separate field of knowledge and is never used for such calculations. It deals with the mysterious heavens and the spiritual and metaphysical nature of the Cosmos. Most of this cosmology deals with the Universe outside our Solar System – what might be termed an impartial objective view as opposed to the purely subjective view of the heavens as seen from Earth. Therefore Vedic Cosmology does not necessarily represent an "Earth-view" of the Universe. Astronomy can only be subjective. It indeed has to be or it wouldn't be relative to us on Earth and wouldn't work. Even if the Universe is viewed from a satellite launched into space it still represents a singular subjective view. Combining several of those to get some sort of perspective still doesn't amount to objectivity. It is only collective subjectivity.

The original Surya-Siddhanta was spoken by the Sun demigod (Surya is another name for Vivasvan, there are many) at the end of the last Satya Yuga. Vedic scholars date this to over two million years ago, circa 2,163,102 BC. The Surya-Siddhanta closely aligns with the understanding of our solar system as western astronomy. Without it there would be no calculation method for Ekadasi.

Śrīla Prabhupāda's spiritual master, as a young scholar named Bimal Prasad, translated Surya-Siddhanta into Bengali around the turn of the 19th century (1800/1900), for which he was later awarded the title Bhaktisiddhanta Sarasvati. It is highly unlikely that as pure devotees in the line of disciplic succession neither would Bhaktisiddhanta have ever touched nor would Srila Prabhupada ever mentioned such books if they were bogus just because they align with western astronomy.

We should therefore accept the Srimad-Bhagavatam and the Surya-Siddhanta as bona fide even though they appear contradictory, because they are accepted by great Vaishnavas, Their Divine Graces Bhaktisiddhanta and Bhaktivedanta.

All this Flat Earth, Moon Landing Hoax, the Moon is further away from the Sun arguing, etc is a complete waste of time. It distracts us from the real point of Bhakti-yoga and appears to be prajalpa, idle talk, nonsense jibber-jabber.

I present my unqualified opinion in the hope that we can all drop this endless riddle and move on. 

Hare Kṛṣṇa