Scientists are about to set sail on a mission to solve the mystery of where some walruses travel in the summer.
They will be heading to Greenland to attach satellite tags to the huge animals as they laze about on the ice.
The tags will beam information up to a satellite in space, which will then let the scientists know where the walruses are travelling each day.
Readers of the Newsround website will also be able to see where the beasts are moving on its Walrus Watch map.
At the moment, nobody knows where the walruses of Greenland migrate to in the summer.
Walrus expert Erik Born, from the Danish Polar Institute, said: "We want to find out where they are going."
The satellite tags will also help scientists to find out more about the threats that the big beasts face. The project has only just started - and once the walruses are tagged, we're going to link to the map showing what they're up to.
In Greenland, they are hunted for their meat by local people, and companies searching for oil may also be disturbing their feeding areas.
Walruses like to rest on ice
And like polar bears, walruses could also be under threat from global warming.
Rising temperatures will melt the ice walruses like to rest on after their trips out to sea.
A BBC reporter will be joining the scientists as they travel out to Greenland.
Rebecca Morelle said: "Walruses are enormous, they have huge tusks and beady red eyes - and they are famous for their bad tempers.
"It will be really exciting to see what they are like in real life!"