On a previous expedition to that region, scientists had wanted to study the rivers that lay below the ice. These rivers were accessible via vertical ice shafts known as moulins. However, the researchers were only able to rappel 130 meters down (427 ft). The moulins can be as deep as 300 m (984 ft), but the ice structure is dangerously unpredictable at such depths. For the 2018 expedition – which was sponsored by outdoor apparel company Moncler – Sauro and his team rappelled part way down some of the moulins, but then remotely piloted an Elios drone the rest of the way. Utilizing its HD camera and LED spotlights, the drone relayed real-time video of a previously undiscovered lake at the bottom of one of the moulins. #icecaves #greenland #nature https://newatlas.com/drones/flyability-elios-drone-greenland-ice-caves/