It all depends on whether the software defaults to some observing location on the Earth's surface (eg the Royal Observatory), or to the center of the Earth. I was making a conservative assumption that it could do either one (having seen both behaviors in different astronomical software), but your argument is only correct if it's the latter.
It does default to center of Earth. However even if the default wasn't center of the Earth, that couldn't alter the apparent size of the Earth from the perspective of the Roadster. It would've altered the parallax.
Thank you! This is the first I've heard either way.
I do hope you can overcome the curse of knowledge[1] to see how the original post was ambiguous without that information. I simply had to know a-posteriori that the software worked like that (I didn't, the manual[2] offered no clues, and I hadn't yet re-done the calculation).
>However even if the default wasn't center of the Earth, that couldn't alter the apparent size of the Earth from the perspective of the Roadster.
I know the software doesn't rearrange the sky, but my hope is that you can understand how I arrived at that particular off-by-a-factor-of-two error[3] (oddly, by assuming less than I should have).
