Divers have pulled a half-tonne suspected meteorite from a Russian lake, said to have been part of a meteor whose ground-shaking shockwave hurt 1,200 people in February.
The meteor broke up into myriad pieces, some no bigger than the size of a fingernail, that scientists are still finding across the remote region.
Much of the debris landed in a local lake called Chebarkul that the divers entered on Wednesday, in an operation covered live on national television.
Broadcasts showed a team pull out a 1.5-metre long rock from the lake, after first wrapping it in a special casing while it was still underwater.
The boulder was then pulled ashore and placed on top of a massive scale for the all-important weighing, an operation that quickly went partially wrong.
The rock crumbled into several chunks as scientists began lifting it from the ground with the help of levers and ropes.
"The rock had a fracture when we found it," one unnamed scientist told the lifenews.ru website in a live broadcast.
"It weighed 570 kilograms before the pieces fell off. And then the scale broke.
"We think the whole thing weighs more than 600 kilograms."
Experts warned it will take time before scientists can certify that the rock they pulled from the lake did indeed come from outer space.
But Sergei Zamozdra, a lecturer at Chelyabinsk State University, told the Interfax news agency he is confident in the find.
"Based on our initial observations... this is a part of the Chelyabinsk meteor," he said.
"This is the largest fragment of that meteor, and most likely, it will be one of the 10 largest meteorites ever found."
The meteor weighed a whopping 10,000 tonnes when it exploded a few kilometres up in the air with the force equivalent to 30 of the nuclear bombs dropped on the Japanese city of Hiroshima during World War II.
United States scientists said an object that large usually approaches Earth only once every four decades.