Grabbing a bit of comet that's racing through the solar system at 150,000 miles per hour, spitting out ice, rock and dust sounds slightly tricky.
But researchers at Nasa's Space Flight Centre are in the early stages of coming up with a way to collect scientific samples - a space harpoon.
They want to send a spacecraft to meet a comet, then fire its harpoon into the rock while hovering above. Once it collects soil samples, the harpoon can be reeled back to the space craft and taken back to Earth for analysis.
Using the device would allow samples to be collected from places that are too difficult for a spacecraft to land on.
Harpoons are traditionally used in fishing, where a spear would be too difficult to collect. Because the spear is attached to a rope or chain, the fish or whale can be hauled out of the water.