inconceivably large

relating or belonging to the science of astronomy; "astronomic telescope"

relating to the study of celestial bodies including planets, stars, and comets

unit (A.U.): The average distance between the Sun and the Earth, often used when describing distances within the solar system. 1 A.U. = 150 million kilometers, or 93 million miles.

Of or pertaining to astronomy; in accordance with the methods or principles of astronomy.