Expedition by leading chemistry institute finds area where it fell.
Mi-8 delivered Hannah McKeand and Canadian companion to remote island weather station but crashed soon after, as pair abandon North Pole attempt.
The anti-Kremlin campaigner will serve remaining time in jail clinic in Siberia.
Scientists intrigued over 'space rock' found 35 years ago, before being dumped in a geologist's fish tank.
Her anti-Putin bandmate Maria Alyokhina was freed earlier from a jail west of the Urals.
Family find her again after 9 years, now aged 25, some 4,000 km from home, but mother killed herself thinking her daughter was dead.
The skill of ivory softening was used more than 12,000 years ago to make tools - or decorations - that still puzzle modern science.
A disease that afflicts one in two million transforms soft tissues into bones.
The new 6.5 kilometre rail link will open in 2017 across the world's 10th longest river.