Image credits: NASA/JHUAPL/SwRI.NASA’s New Horizons spacecraft spied several features on Pluto that offer evidence of a time millions or billions of years ago when — thanks to much higher pressure in Pluto’s atmosphere and warmer conditions on the surface — liquids might have flowed across and pooled on the surface of the distant world. “In addition to this possible former lake, we also see evidence of channels that may also have carried liquids in Pluto’s past,” said Alan Stern, Southwest Research Institute, Boulder, Colorado—principal investigator of New Horizons and lead author of the scientific paper.
This feature appears to be a frozen, former lake of liquid nitrogen, located in a mountain range just north of Pluto’s informally named Sputnik Planum. Captured by the New Horizons’ Long Range Reconnaissance Imager (LORRI) as the spacecraft flew past Pluto on 14 July 2015, the image shows details as small as about 430 feet (130 metres). At its widest point the possible lake appears to be about 20 miles (30 kilometres) across.
NASA’s Hubble Space Telescope has spotted a small, dark moon orbiting Makemake, the second brightest icy dwarf planet — after Pluto — in the Kuiper Belt. The moon, provisionally designated S/2015 (136472) 1 and nicknamed MK 2, is estimated to be 100 miles in diameter. Makemake and its moon are more than 50 times farther away than Earth is from the Sun.
The science team of NASA’s New Horizons mission has produced an updated global map of dwarf planet Pluto that includes all resolved images of the surface acquired 7-14 July 2015, up to 400 metres/pixel resolution. Many additional images are expected in autumn 2015 and these will be used to complete the global map.
The long-awaited fly-by of Pluto by the New Horizons spacecraft, on 14 July 2015, was an event 85 years in the making, following Pluto’s discovery by Clyde Tombaugh in 1930. Since then, Pluto has gone from planet to dwarf planet, but despite protestations from the New Horizons team, its reclassification never really changed the mission or the importance of what it would find at Pluto.