We don't know. NASA are known lying liars that lie. Too many KNOWN faked photographs.

We don't even know the speed of light, or how light travels. So, we cannot adjust the distortion of our optics for what really exists.

It appears that you cannot see the sun or the stars while in space (but we don't know this for sure)
The visibility of these objects seems to be an effect of our atmosphere.

There are reports that the sun is hollow. That it is not this big nuclear furnace.

It is thought that the moon is spherical because of the shadow line on it.
However, when it is tried to be exactly calculated there are anomalies.

You have student astronomers, and when they get time in an observatory, they are all admonished not to use the telescope to look at the moon.

You take all of these things and you add them up, and you come up with a big fat question mark.

(The earth is not flat, or spherical. Its actual shape will warp your brain.)