From the lands yet to see the film I come, Britain to be precise.
I'm just hedging a bet here, but I reckon your ghosts could well be the crew of the Liandra past, who are not dead, but infact trapped in the dimension the hand are coming from. It might be the real reason the Ranger Rustbucket was sent out a second time in such a poor state. It has a unique connection with what the high ranking Rangers suspected the current mission might encounter.
To quote Grig in "The Last Starfighter"
"Death is a primitive concept.... I prefer to think of it as battling evil... in another dimension!"
So there may yet be a twist.
Though this is pure speculation!
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Back when I was a kid in Sunday School, Father Minkowski once said: "Given the crucifixion was a terrible thing for anyone to endure, if you could go back in time 2200 years, would you prevent the crucifixion of Christ?" Well after a heated debate, we all agreed the answer was no. The crucifixion was necessary to redeem the world. - Lt. John Matheson "The Needs of Earth"
"We live for the One. We die for the One!"