I'd expect Augustine to speak about the motion and orbit of the stars because while Augustine knew the earth was round, what he didn't know is that the earth orbited the sun, spinning upon its axis, and thus the motion of the stars was, primarily, only apparent motion.
Moreover, Augustine was not actually wrong to speak of stars as having motion and orbits--because they in fact do. Only the earth isn't the center point of their motion or orbit. Rather all the stars in our galaxy move relative to one another, and most importantly, orbit around the galactic center. And this is repeated throughout the many galaxies of our material universe--and these galaxies themselves are in motion and relative to one another.
Augustine, of course, lived at a time when he couldn't know almost any of that. However the wisdom expressed in his words are clear as day: When the plainness of evidence is staring you right in the face, don't try and use Scripture to go against observable objective reality, you aren't doing Scripture a service, you are making Scripture look stupid and unreliable; and it doesn't do Christianity any service, because it only brings Christianity--and literally billions of believers all over the world--under a mockery. Not a mockery on account of Christ, oh no, that would be blessed; but rather mockery because the ignorance of some Faithful becomes associated with all the Faithful.
This is self-evident, for Christians in the 21st century, viewed through the lens of popular culture, is that of science-denying bigots who are willing to toss our most sacred principles and values into the fire at a moment's notice, and that we are known not by our love as disciples of Jesus, but as a people who look as far from Christ as day is to night. So much so that, one of the foremost moral philosophers of the 20th century, Mahatma Gandhi could say, "I like your Christ, but I do not like your Christians; your Christians are so unlike your Christ."
When we have received, as the word of God, the utmost commandment to love and be known by our love, and that through our love we should be known as the people of Jesus, and that we claim to worship, and follow, the God who made all things, both things above and things below; and yet we deny the work of His hands, calling Him a liar, and misrepresent Him over and again. And worse, "true religion" becomes a Pharisaical farce of hypocrisy and pietistic theater.
-CryptoLutheran