The following questions and answers are taken from “Vedic Cosmography and Astronomy” by Dr. Richard L. Thompson (SadApUta dasa) which was published in 1989 by the Bhaktivedanta Book Trust (used with permission). SadApUta dasa is a founding member of the Bhaktivedanta Institute, the scientific branch of ISKCON.
[From Chapter Eight – Questions and Answers]
Q: Using radar and lasers, scientists have recently obtained very accurate estimates of the earth-moon distance. This distance is about 238,000 miles. How do you reconcile this with Vedic calculations?
A: According to sUrya-siddhAnta [see footnote], the distance from the earth globe to the moon is about 258,000 miles. This is in reasonable agreement with the modern value.
Q: The Vedic literature says that the moon is higher than the sun. How can this be?
A: In Chapter 22 of the Fifth Canto, the heights of the planets above the earth are given, and it is stated that the moon is 100,000 yojanas above the rays of the sun. In this chapter, the word “above” means “above the plane of BhU-maNDala”. It does not refer to distance measured radially from the surface of the earth globe. In Section 4.b we show that if the plane of BhU-maNDala corresponds to the plane of the ecliptic, then it indeed makes sense to say that the moon is higher than the sun relative to BhU-maNDala. This does not mean that the moon is farther from the earth globe than the sun.
For example, if point A is in a plane, B is 1,000 miles above the plane, and C is 2,000 miles above the plane, we cannot necessarily conclude that C is further from A than B is.
Footnote: Several times in the Caitanya-caritAmRta, Srila Prabhupada refers to the sUrya-siddhAnta which was spoken by a messenger from the sun-god, sUrya, at the end of the last Satya-yuga. It was translated into Bengali by Srila BhaktisiddhAnta SarasvatI. In the Caitanya-caritAmRta (Adi 1.3.8p), Prabhupada writes:
These calculations are given in the authentic astronomy book known as the sUrya-siddhAnta. This book was compiled by the great professor of astronomy and mathematics Bimal Prasad Datta, later known as BhaktisiddhAnta SarasvatI GosvAmi, who was our merciful spiritual master. He was honored with the title SiddhAnta SarasvatI for writing sUrya-siddhAnta, and the title GosvAmi MahArAja was added when he accepted sannyAsa, the renounced order of life.