Examining the planets, it's pretty clear that the system in the main menu isn't Sol.

And I have this sneaking suspicion that it's the system to which we need to go in order to finish the main quest, the idea being that, after going back to the main menu, the player is supposed to go, "Ohhhh...I see what you did, there."

...am I right? I mean, obviously, saying so would be kind of a spoiler, but I'm not sure how we'd find it without exploring, without clues, and it would probably kick our butts if we don't go finding ship-upgrades...so...

Well, just askin'.