Mirror, Mirror - Telling the Future in LotR

[akhtene]

[img]smilies/smile.gif[/img] A good prophet (or a politician) is the one who can tell what what is sure to happen, and then to plausibly explain why it hasn't. [img]smilies/smile.gif[/img]

But , seriously, was there any prophesy (or whatever) about Gandalf entering Moria? As Aragorn seems really worried for the wizard

It is not of the Ring, nor of us others that I am thinking now, but of you, Gandalf. And I say to you: if you pass the doors of Moria, beware!

So does Aragorn know something? And why Gandalf himself unruffled?