"They will probably try to liaise with civilian satellite operators to see if there are any who also picked up the trail on infra-red sensors so that they can publicly release that data," he said.
The crash site is vast, and experts said rebel fighters may have removed key evidence in the chaotic hours after the disaster, as they joined emergency workers and local coal miners to comb the wreckage and recover the bodies.
Charles Heyman, editor of "Armed Forces of the EU," said missile casings could help establish who had supplied the weapons that brought down the plane. But he said it was likely that the rebels - if they fired the missile - would have removed any missile-casing debris from the scene.
Heyman said the missile launcher would bear ID numbers that could establish whether it was recently supplied by Russia or came from Ukrainian forces.
But he said if rebels mistakenly targeted a commercial airliner, thinking it was a Ukrainian military plane, they may have subsequently fled and taken the missile launcher into Russia.
The Ukrainian Interior Ministry released video purporting to show exactly that: a truck carrying a Buk missile launcher with one of its four missiles apparently missing, rolling toward the Russian border. The ministry said the footage was captured by a police surveillance squad at dawn Friday. There was no way to independently verify that claim.
"If I was the rebel chief of staff, I'd have had it taken away, dismantled and blown up," Heyman said, "and then bury the pieces in a swamp."
