If they had been filled with liquid 02 they would not have survived reentry.  If the didn&#x27;t burn up, they would hand landed like bombs.  If it was rocket fuel, say hydrazine (these are too small for the kerosene used on lower stages) this would be a public health issue.  Helium would be my bet for spherical tanks.  Perhaps this was from some of the &quot;ghost&quot; boosters that are floating in low orbit such as from the SL-16 r&#x2F;b launches in the 80s.<p>Has this come down in the north&#x2F;south I would assume it was from a not-public imaging sat or launch, but vietnam is near enough the equator that it could be anything.