How Ancient Greeks & Romans viewed Astronomical objects

[Cipher]

Do we know how they perceived Astronomical objects like planets and stars? For example, did they saw stars as an object like the sun, only billions of kilometers away, or just as a shiny dot in a night sky?

[M. Demetrius]

It's been a long time since I read anything on that topic, but it seems to me from my faded memory, that they really had no idea what stars and planets were, and regarded the visible planets as stars that travelled in a predictable path. I'm pretty sure they didn't get the vastness of space, nor the notion that stars were distant suns, and planets were different, distant worlds. It wasn't until much later, with the invention of the telescope, that many of these mysteries began to be unraveled.

However, being good observers, the ancients noticed that stars "twinkle" and planets do not. I doubt they understood the differing diffraction of emitted light vs. reflected light, but they were able to see the difference, of course. And they were able to note how the seasons corresponded to certain star patterns, which we call constellations, coincided with seasons. That they assigned attributes to those constellations and assigned to them "powers to affect people and things" persists to this day, in spite of plenty of good science to contradict that notion.

[Epictetus]

I believe they differentiated between the Sun and stars, for the most part. Ptolemy, working on what people had discovered before him, had a good grasp of large distances involved, and he put the inner planets in more-or-less proper order, but the scale was beyond him. The stars (but not the planets) were a fixed distance from the Earth in his system, I think.

Lucian, in his amazing True History, has the heavenly bodies as solid physical locations, not as fire or aether. At one point he calls the Moon an “island with air for sea.” I think it notable that he wrote of the Moon as a physical place, independent of the Earth and suspended in space (“air”). In other words, he conceived of the Moon as more-or-less what it actually is.

But in Lucian’s story many of these heavenly bodies are populated by fantastic men or creatures. I don’t think Lucian was actually trying to say that the Moon and Sun were populated. He was an enormous wit, and I think he was being satirical and his intent with the story was not a simple narrative. This would be similar to an ancient version of Gulliver’s Travels.