Aragorn's first visit to Moria

[Inziladun]

Originally Posted by Alcuin

The Orcs in Moria had been sent there from Dol Guldur. Aragorn was an expert on Orcs, hunted them, and may have entered the Mines as part of a scouting expedition to learn about their movements, either on his own or in cooperation with Lórien. After all, Lórien was an obvious target for an attack from either Dol Guldur or Moria or both simultaneously. Since we don’t know anything else about when Aragorn entered Moria before III 3019 or his reasons for going there, I would venture that this is the single most likely reason.

Seems he could have at least filled in the Fellowship on what he knew, if that was the case. Gandalf made it clear he didn't know the state of things in Moria; he even thought it possible Balin and his group would be there. One would think the knowledge that Orcs were present in Moria was rather important. The Company would have been more careful; even Pippin might have been able to check his "hobbit walking-party" mentality at the Gate.