Floating hills of water-ice found on Pluto
According to the data received from NASA's New Horizons spacecraft, numerous hills of water-ice are floating atop frozen nitrogen on Pluto. The hills, situated on a vast ice plain named Sputnik Planum, move like icebergs floating on nitrogen, carbon monoxide and methane that has the "texture of toothpaste". This happens because "water ice is less dense than nitrogen-dominated ice".