As said by Aristotle, "It is the mark of an educated mind to be able to entertain a thought without accepting it." In other words, @davedickeyyall I am not necessarily accepting this but it certainly did made me think outside the box and start questioning what thing is real.

To begin, the pictures in space could easily be Photoshop'ed so to speak. Not to mention that computer generated simulators are capable of creating wonderful videos and images. With the technology we are openly known to have thus far, a lot of things can be easily faked and optical illusions are the easiest.

Next, with the proper technology, the change of the seasons could also be synthetically created. Who are we to say how advanced technologies could get, just because we don't see it and don't understand it, it does not mean that there are not existing technologies out there that are capable of doing amazing things.

And I am not sure If we have to live in a round planet in order for gravity to exist. Maybe gravity can exist on a flat plain as well. Not to mention that it could very well be possible to simulate gravity with the proper technologies. We have no idea how far and what the limit is on technology. If there really are more advanced species out there and more advanced technologies that we are not aware of who is to say that all these things are not possible.

Again, I am not accepting this because it certainly is a wild idea but I don't have enough evidence to back either side. Therefore my opinion is neutral.