Quote from: StrangeShape on Jan 16, 2012, 07:45:55 PM
That why I always assumed the ship has been lying there for millions of years, which was that much more intriguing for me. The idea of some very ancient evil which was awaken by the crew of nostromo
As long as the environmental conditions remain the same, a mummified corpse can last thousands, if not millions of years...which would be exactly the case on an alien world which has a reducing atmosphere, low water vapor content, and no microorganisms. Also, it was inside the ship, so it was protected from winds and sand that would ablate the corpse over time, as well as protected from UV radiation (from the planetoid/moon's) sun.
Note: the mummification process could happen in as short a time as a few months. That would be the lower limit. The upper limit could conceivably be in the hundreds of thousands, if not millions of years. From a purely scientific standpoint, it gets a bit more problematic the longer the geological time. Would the Jockey spacecraft remain essentially intact over millions of years of being exposed to high winds with potentially ablative grit? Also, is the planetoid tectonically quiescent? If not, and it is active, then that poses other problems the longer the time duration (e.g. volcanism, geologic uplift or rifting, etc.)