http://www.foxnews.com/scitech/2012/03/23/huge-ufo-fragment-discovered-in-siberia/

"Following the initial examination, an official for Roscosmos, the Russian space agency, reportedly said: "The object found is not related to space technology. A final conclusion can be made after a detailed study of the object by experts."

"Nick Johnson, head of NASA's orbital debris office, said there isn't sufficient information about the object for him to make a full assessment, but it doesn't appear to be part of a spacecraft.

"The object almost certainly is not related to a spacecraft," Johnson told Life's Little Mysteries. "It also does not look like part of a launch vehicle which has fallen from orbit. However, we cannot be definitive in our judgment without better photos and other data. For example, the date the object fell is vitally important, but I did not see reference to it."

 

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Nobody knows - hence the use of the word "unidentified".


Since it uses titanium it has to be post-1955ish. Found so recently (and not totally buried) means more likely it was made far more recently.


Since it's so damned heavy (440+ pounds) yet nothing more than an empty shell it's highly unlikely to be part of a space or aircraft. My guess? The cap to some kind of storage vessel for volatile materials (liquid oxygen perhaps, something pressurized and dangerous)

 

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Looks like a piece of this -> http://www.foxnews.com/scitech/2011/08/24/russian-space-ship-fails-to-reach-orbit/

 

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