Aragorn's first visit to Moria

[Inziladun]

Originally Posted by Alcuin

In any event, when the Company of the Ring fled after Gandalf fell into the abyss, there was a company of orcs guarding the entrance. We do not know if this was typical after the orcs re-established themselves following the Battle of Azanulbizar: perhaps they were watching for travelers through the Mines (i.e., the Company of the Ring), or perhaps it was normal procedure.

I've always connected the strong Orc-guard on the east-gate to the Company's presence in Moria. I can see them certainly keeping a watch on the Dimrill Dale under normal circumstances, but that's probably all that was required. As long as they had a means to quickly assemble all their forces in Moria if need arose, I don't see why they'd have needed to retain such a strong guard constantly.

Originally Posted by Alcuin

Gandalf said that only he had passed completely through the Mines. Since he exited through the Doors of Durin, he must also have entered from Dimrill Dale. And since he alone had transited the Mines, Aragorn cannot have accompanied him, giving us the additional information that Aragorn also entered and left through Dimrill Dale.

I too, doubt that Aragorn and Gandalf made their journey into Moria together. The dialog between the two doesn't seem to support that. Aragorn almost certainly did enter from the east like Gandalf, though, as neither knew the password to open the west-gate.
However, where does it say that only Gandalf had made the full journey through Moria? Aragorn says of his encounter there:

'I too once passed the Dimrill Gate, but though I also came out again, the memory is very evil.'

I don't think one can extrapolate from that that Aragorn didn't make it all the way thorough.

As for the original question of why Aragorn entered Moria, ask yourself, 'Why did Gandalf"? Lacking an exploratory motive, both would have merely been looking for a shortcut through the Mountains at some point, for whatever reason of needing haste.

[Puddleglum]

Originally Posted by Inziladun

I don't see why they'd have needed to retain such a strong guard constantly.

As for the original question of why Aragorn entered Moria, ask yourself, 'Why did Gandalf"?

Just a few quick thoughts.

• Keeping a guard seems to be a very normal thing in a dangerous world. The Elves of Lorien did it; The Dwarves of Erebor did it; The Bree-landers did it; The Bucklanders did it (even before the Ruffians took over); The Rohirrim did it; The men of Minas Tirith did it; The orcs of Cirith Ungol did it (until distracted by in-fighting); Minas Morgul did it; Saruman did it in Isengard; and so on. While Saruman's & Sauron's search for the Ring may have (I suspect "DID") play a part - the presence of a guard seems very plausible to me in any event.
• Gandalf spent a fair amount of time search high & low for Thrain. That included even venturing into Dol Guldur and the dungeons of the Necromancer. Given the connection between Thrain and Moria (he wanted to venture in after the battle of Nanduhirion), Gandalf could well have explored there himself as part of his search.
• Perhaps Aragorn ventured in as part of his hunt for Gollum. He doesn't tell much about his search after Gandalf gave up (other than tracking him to the confines of Mordor and finding him in the Dead Marshes), but it is at least possible he searched in Moria also.

[Inziladun]

Originally Posted by Puddleglum

Keeping a guard seems to be a very normal thing in a dangerous world. The Elves of Lorien did it; The Dwarves of Erebor did it; The Bree-landers did it; The Bucklanders did it (even before the Ruffians took over); The Rohirrim did it; The men of Minas Tirith did it; The orcs of Cirith Ungol did it (until distracted by in-fighting); Minas Morgul did it; Saruman did it in Isengard; and so on. While Saruman's & Sauron's search for the Ring may have (I suspect "DID") play a part - the presence of a guard seems very plausible to me in any event.

The Orcs apparently weren't that alert for intruders, at least not from both directions, east and west. There is no indication they were aware enemies were in the Mines until Pippin dropped the stone into the well. As I said, I can see the purpose of keeping a watch, but not necessarily a strong force like the one the Company encountered.

Originally Posted by Puddleglum

Gandalf spent a fair amount of time search high & low for Thrain. That included even venturing into Dol Guldur and the dungeons of the Necromancer. Given the connection between Thrain and Moria (he wanted to venture in after the battle of Nanduhirion), Gandalf could well have explored there himself as part of his search.

Ah, you're right there. Gandalf indeed told the Fellowship that's why he had gone to Moria.

Originally Posted by Puddleglum

Perhaps Aragorn ventured in as part of his hunt for Gollum. He doesn't tell much about his search after Gandalf gave up (other than tracking him to the confines of Mordor and finding him in the Dead Marshes), but it is at least possible he searched in Moria also.

The trouble with that idea is that Aragorn's search for Gollum apparently didn't begin until Gandalf asked him to help TA 3001 (The Tale of Years). Balin's Dwarf-colony had been destroyed in 2994, and the Orcs had obviously returned to Moria at that point.
When the Company was debating whether to go through Moria, Gandalf says this:

If there are Orcs there, it may prove ill for us, that is true. But most of the Orcs of the Misty Mountains were scattered in the Battle of Five Armies.

If Aragorn had been through Moria recently enough to have looked there for Gollum, shouldn't he have known there were Orcs there, and warned the Fellowship?

[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.

[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.

[Alcuin]

Originally Posted by Inziladun

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.

That depends upon when Aragorn went to Moria.

According to the Tale of Years, Aragorn was in Lórien in 2980. Then he met Arwen there, and their engagement began (they “plighted their troth”). Balin did not enter Moria for another 9 years. If Aragorn entered Moria around 2980 to scout the situation there, and Balin entered sometime afterwards, Gandalf would have had the better information.

Nor does it seem likely that Aragorn entered Lórien again before he came there with the Company of the Ring. Celeborn hints that this was the situation. Haldir indicated that the Elves were aware that there were again Orcs in Moria, or at least encroaching from the direction. Maybe the Elves did not know they were coming from Moria, but only from the Misty Mountains. (It seems obvious to me, but then, I’m not a couple of thousand years old: maybe I’m being “too hasty,” as Treebeard would put it.)

A better question might be why Elrond was unaware of the presence of Orcs, since he had been recently in communication with Galadriel and Celeborn through Elladan and Elrohir, who traveled to Lórien and returned following the Council of Elrond. Perhaps we should consider that the presence of Orcs in Moria was taken as a given – if Balin and his colony from Erebor were not there to keep them at bay in some section or another of the Mines, a possibility Gandalf suggested. His only mention of Orcs in connection with Moria was that ([FotR], “Journey in the Dark”)

If there are Orcs there, it may prove ill for us, that is true. But most of the Orcs of the Misty Mountains were scattered or destroyed in the Battle of the Five Armies. The Eagles report that Orcs are gathering again from afar; but there is a hope that Moria is still free.

That could imply that Aragorn and Gandalf had discussed whether there were Orcs in Moria. They did have a running debate about the wisdom of passing through Moria beforehand, part of which Frodo witnessed.

But maybe Aragorn wasn’t looking for Orcs in Moria at all: maybe he was just “an adventurer”, though that would strike me as very “un-Aragorn”. Mere darkness would not have daunted Aragorn. If he didn’t meet Orcs in Moria, do you suppose he got an early glimpse of Durin’s Bane? I vote for Orcs.

[Pitchwife]

Originally Posted by Alcuin

But maybe Aragorn wasn’t looking for Orcs in Moria at all: maybe he was just “an adventurer”, though that would strike me as very “un-Aragorn”. Mere darkness would not have daunted Aragorn. If he didn’t meet Orcs in Moria, do you suppose he got an early glimpse of Durin’s Bane? I vote for Orcs.

I don't mean to slight Aragorn's valour, but I highly doubt that he'd have lived to tell the tale if he'd faced Durin's Bane, and if he had, it would have been unconscionable not to be more explicit in his warnings to Gandalf. On the other hand, I'm not sure that the mere presence of Orcs would have made such a lasting impression on him as to justify the ominous tone in which he speaks of his earlier visit to Moria. So it's rather a mystery to me what exactly he met there that made his memory of Moria so "very evil". Maybe some 'nameless thing' that had become bored with gnawing the roots of the world and ventured up to the lower levels?