I was just wondering how long these probes will last. I don't mean until their RTG's pack in and they can no longer function (which I believe will be in 15 or so years for Voyager 1), but I mean how long can they physically exist? I find it a sobering to think of them possibly outliving humanity and maybe all other traces of our species.
I'm assuming the chances of them being captured by another star system are pretty low so are there any other dangers they could face? Anything that would degrade the crafts over time? What will their lifetime be measured in? Thousands, millions or even billions of years?