It doesn’t have to be the same building. Any building built in 298,000 AD will do.
How long till the Sun dies? That’s when all signs of human civilization (on earth) will disappear. And I fully disagree with the poster above who claims that in all that time it is extremely unlikely that we’ll have colonized outside our solar system. I can’t see how we wouldn’t have by then. The time scales are immense.
Good point.
However, if Homo sapiens has a lifespan on par with other mammals (and there’s really no reason to think we don’t), the species has about 800,000 years left in it. So the last building built by the last person will have to manage another 1.2 million years of exposure after her death to outlast Pioneer 10.
You can’t? Here’s a scenario: mankind is destroyed by forces within before the technology for interstellar space travel is developed. Here’s another: mankind is destroyed by forces without before the technology for interstellar space travel is developed.
Seems pretty easy to imagine to me.
OK; if you insist, I’ll rephrase and remove the colloquialism.
I think there’s a good chance mankind won’t be wiped out completely and will develop insterstellar travel before 298,999AD. That gives it 297,000 years to do so. Though why we’re limiting it to that short a time, I’m not sure. When will the sun die? We have about 5* billion* years to do it in. That’s our hard time limit.
We might have setbacks. Even near extinction a thousand times over, forcing us to start again each time, and we could still do it before our 5 billion years is up.
All it takes is one full extinction for it to be game over for humanity. 5 billion years is a long time as you say and there is plenty of time for one really bad event to happen to end the whole thing.
The key there is “full” extinction.
Sure. I wouldn’t for a moment say it’s not possible. But we’re a lot cleverer than dinosaurs. We have a better chance of continuing, even if we’re reduced to a handful a few times. And if we eventually colonize nearby bodies - even minimally - those odds get even better. As long as we can start again, we’re still here.
None of us know, of course. We’re all guessing here, and some are more optimistic than others. But I think we have a decent chance.
Not to mention that ship 3 needs to accommodate both 1 & 2, #4 would need space for the preceding 3, ad infinitum. It’s going to get crowded out there.
As far as Voyager’s return: I think it’s far more likely some alien race will stumble upon it in transit, monitor its trajectory to determine its source, and return it to us as a gift of intergalactic goodwill. Then eat us.
A new ship would also have to match velocities to pick up earlier-launched stragglers. Which means slowing down significantly and then speeding up again. Which, in space, is generally very expensive, and an interstellar ship won’t be able to afford very large margins. We’d need a truly revolutionary propulsion system to make it practical to pick up stragglers.
I don’t think so, I beleive they just have a slightly different orbit around the galaxy than the sun. As such, the chance of them ever encountering the solar system is close to zero. Space is very, very big.
Yes, geological time can easily destroy mountains. If we died out tomorrow, visible remains of our structures wouldn’t last long, we’d soon be a subject for archeology. This is especially true anywhere cold enough to freeze water, which gets into cracks and expands. Think what a single bad winter does to our roads. A few decades of neglect would probably be enough to reduce a city like New York or London to rubble.
The interstellar wind would also erode them over time. Does anyone have an estimate of how long they would last?
The distances are also immense. There is nothing inevitable about us eventually colonising the galaxy. The technical and political barriers may simply be too great to overcome. I tend to think in terms of energy budget, a key question is whether we will face an energy rich or energy poor future compared to today. I might start a thread in GD to discuss this further.
Nobody said it was inevitable. I was arguing that it wasn’t impossible.
Sorry, but that’s not what you seem to be saying here (bolded).
I find it an interesting subject to think about. I’ll start to think we have a decent shot when we’ve demonstrated the ability to build a self-sustaining artificial environment.
I would really, really doubt that. Once it goes silent, you’d have to be virtually on top of it to see it. Even with alien sensors made of unobtanium. 
Given the scales involved, it’s a little like saying “I dropped a baseball in the Sahara. Some day, someone will find it.” Actually, that’s probably a bad analogy. I’m sure baseballs lost in the Sahara are more like Jupiters lost in interstellar space.
Or maybe not. I read somewhere some years ago (sorry, no cite) the notion that if mankind got itself bombed back to the stone age, we would never again be able to rebuild civilization like we did the first time – the obstacle being that we’ve already consumed far too much of the planet’s non-sufficiently-renewable resources for that. (But I don’t recall that the source mentioned specifically what those depleted resources are, other than maybe petroleum ETA: or other fossil fuels in general. Agricultural resources maybe also.) (Does anybody else here know of this theory?)
We’ll just beam the aboard, Scotty! 
If you dropped a baseball into the ocean (someplace not too terribly deep, though), dolphins will find it.
I’m glad you’re sorry; and indeed that your grasp on my position is greater than mine, despite my later clarification. If you scroll down a few posts from the one you quoted, you’ll see said clarification.
interstellar=no wind
I don’t know that stellar winds do anything to these probes anyway. Wreck the instruments, yes. But the actual vehicle itself? Nah. I’ve seen nothing that implies they’ll ever be destroyed other than by hurtling into something really big, or something really hot. Neither type of thing is on any of their paths for the near future, if at all.
There may be more stories with a similar theme, but one is “On the Shoulders of Giants” by Robert J. Sawyer. The original crew took 1200 years to get to their destination, finding out when they arrived that it was well populated by sixth generation descendants of the first people that arrived at the planet in question (those first people having left long after the original crew). Ultimately the original crew decided that it was pointless staying with all those descendents of people that had come after them, got their hands on a new spaceship and headed off to the Andromeda galaxy. The story is copyright 2000. I guess that’s not 30 years ago, but like I said, there may be similar themes.
ETA Oops - I see others have mentioned older stories.
Don’t forget the Voyagers have music and pictures and a recording of Ann Druyan’s brain waves so a sliver of human thought will last virtually forever.
The original claim was that the space probes would be the last traces around from human civilization because the Earth would be destroyed. The Earth isn’t going to be destroyed at least in a total sense. That isn’t really conceivable in the next few hundred million years if not many times longer. It is true that you can point to anything you can see now and chances are it won’t be around in 200 years let alone 2000 or 2,000,000 years but oddities happen.
Archaeology and paleontology wouldn’t exist if some improbable series of events didn’t make it possible to find remains of things thousands, millions, or hundreds of millions of years old even today right under our feet. The total volume of those that survive on Earth no matter what else happens will still be greater than a couple of space probes and much more discoverable by alien scientists wondering what happened to us someday.
The Earth and all that’s left on it will be destroyed in about 5 billion years, though.
Besides the Pioneer and Voyager spacecraft, there’s also New Horizons and its third stage that are on separate trajectories to leave the Solar System. I’m fairly sure those 6 items are the only ones on escape trajectories.
Cosmic rays will embrittle their metal and UV radiation should degrade any exposed plastic. After enough time, they should be rather fragile so an encounter with a small dust grain may be all it takes to destroy them.
By the way, how can they be said to have left the Solar System when they haven’t even reached the semi-major axis (519 AU), much less the aphelion (937 AU) of Sedna? Doesn’t that planetoid count as part of the System?