Planetary researchers analyzing images from NASA’s New Horizons spacecraft have found evidence that liquid nitrogen may still be seeping up from beneath the dwarf planet’s giant glacier, Sputnik Planitia, marking the first suggested case of recently flowing liquid on Pluto’s surface. Sputnik Planitia is a 1,200 x 2,000 km (746 x 1,243 miles), nitrogen-ice-filled basin that fills the western lobe of Tombaugh Regio, Pluto’s famous heart-shaped structure. Because solar heating and other conventional explanations are too weak or too diffuse to produce such sharply bounded features on Pluto, liquid nitrogen is the best explanation. “Pluto has many unique terrains seen nowhere else in the Solar System, and this area of Sputnik Planitia is one of them.” “In addition to suggesting that liquids have recently expressed themselves on Pluto’s surface, this result also suggests a new kind of time-variable feature on Pluto.”