Newton's laws of motion and gravitation achieved their original success when applied to the solar system. The first definite evidence that they were … - Gerald James Whitrow

By the time of Comte, scientists unanimously rejected the idea that there was any essential difference between celestial and terrestrial matter, but they still had no empirical evidence to support their view any more than had Aristotle to support his, and to the positivist philosopher it seemed that none could ever be obtained. ...The possibility of a solution to this problem appeared shortly after Comte's pronouncement with the rise of the science of astronomical spectroscopy...

The basic objection to attempts to deduce the unidirectional nature of time from concepts such as entropy is that they are attempts to reduce a more fundamental concept to a less fundamental one.

It became clear that our Galaxy is only one system among many, and that the universe is far vaster than the particular stellar system to which the Sun and planets belong. Since then developments have been more rapid than at any time since the days of Copernicus, Digges and Bruno when the geocentric hypothesis of the cosmos received its death-blow.