*brain failure*
We knew everything about the moon. Then I post an article. GIANT CAVERN DISCOVERED! I think you just got owned. Prove to me beyond any doubt we know 100% everything there is to ever know about the moon, and that it is all boring and useless. Please.
I give you a ball of, say, clay. I let you prod it, look at it, touch it, smell it and whatever you want to do with it until you conclude that there is absolutely nothing interesting about it. Then I poke a hole in it with my pinky finger. Would you think that it is now suddenly more interesting?
No, I am not saying that the cave on the moon wasn't there before. Although it would have been fun if your further argument was based on picking on that, but that would've been too easy - I'll play fair.