It is Impossible

[SM]

Considering the lack of precedent, Dallas might be correct or he might not.  As of right now - he's not.

[Huggs]

Well, there it is.

[SM]

If it turns out he's right - that can work too.

[Local Trouble]

Are you obligated to remain neutral on your preference?

[SM]

No. I don't have a preference.

[Local Trouble]

You have truly achieved Kolinahr.

[Necronomicon II]

Here's something that makes the idea of the derelict not being so ancient make sense in light of what occurs to it in Aliens.

If the Derelict is a recent crash on LV-426, that does provide some added justification for the volcanic destruction of the vessel in the SE of Aliens. It seems awfully convenient that it would succumb to such a fate during that meager fifty-seven year span after the Nostromo finds it and while the colony was being set up if it had been there untouched for thousands of years...So, there was no volcanic action in those alleged thousands of years?
But if it had only crashed, say, a decade or so before the events of Alien, I'd buy it as being much more likely for everything significant to happen to the ship in such a compressed span of time.

Boom.

[The Old One]

The set up of the Atmosphere processors could've easily been responsible.

[SM]

So, there was no volcanic action in those alleged thousands of years?

There was.  Dallas, Kane and Lambert walked past a bunch of geyser vents on the way to the Derelict.

[The Old One]

Indeed.

& Ridley Scott loves his smoke.

[Immortan Jonesy]

Interesting. I'm wondering if this theory can explain the unusual physical apareance of that lone Engineer (aka Space Jockey).

[SM]

Indeed.

& Ridley Scott loves his smoke.

Geysers outside, venting pipes inside.

[Huggs]

We know from Prometheus that the engineer space-crafts can remain in perfect operating condition, even after 2000 years when they have been well protected against the elements. The craft on LV-426? I don't know. If it is (in fact) something that is grown or composed of any kind of organic material, would it not rot eventually?

Or does it feature the same kind of cell shedding silicone (say that 3 times fast) replacement that the facehugger does? Maybe it's also dead, but protected in a way.

Indeed.

& Ridley Scott loves his smoke.

Indeed. Where it's getting blown, is another matter entirely.

[Immortan Jonesy]

The ships of Prometheus were stored in hangar. Also, I saw a lot of vegetation inside the David's juggernaut when Oram and the others were looking for the source of the signal.

[Huggs]

The ships of Prometheus were stored in hangar.

Exactly. So they'll fire right up, even after 2000 years when well kept. There was even enough power to keep the engineer alive the whole time. So is it possible the derelict is even more ancient? Or is the weather on LV-426 really that bad?

What's more, how long are the eggs viable? Because there must be a connection between the juggernaut and the eggs, given the chesbursted engineer. If there is a limit to how long the eggs can remain dormant and viable, that would narrow down your timeframe.