In mid-September 2008, ninety rubber ducks were dropped by a NASA scientist into tubular holes (what are called moulins).
They were inserted within the fast-moving Jakobshavn Glacier (NASA: “Fastest Glacier in Greenland Doubles Speed”) near Greenland in order to track the positions of melting ice under the Greenland ice shelf in summer months
Alberto Behar, based in the Mobility and Robotic Systems Section at the NASA Jet Propulsion Laboratory (Pasadena, California) made the drop of the rubber duckies.
Behar was hoping to retrieve the toys after they floated along channels made by the melting waters. Such travels would identify the path of melting ice.
However, all of the rubber ducks are missing. Thus, the call for help from NASA (aka: “Houston, we have a problem”).
The Guardian article “Nasa hunts for its rubber ducks,” states: “Although low-tech, the $2 ducks were chosen for their buoyancy and for their ability to withstand low temperatures. Nasa is offering a modest prize of $100 to the first person who finds a duck. The ducks have an email address stamped on them, together with the word "reward" in three languages, including Inuit.”
Page two mentions comments from Dr. Behar, along with contact information in case you find one of these missing rubber ducks.