The American space agency, NASA, has made an appeal for public help with one of its stranger experiments.
NASA wants information on the fate of 90 rubber ducks deployed on a special mission to pinpoint where melt waters go under the Greenland ice shelf in summer months.
The bathroom toys were put into one of the crevasses which drain vast amounts of Greenland's melt waters in the hope they would pop out eventually and reveal the route taken by the water.
The NASA scientist Alberto Behar says the agency is still hopeful of seeing its ducks again.
