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.
Astronomers using NASA’s Hubble Space Telescope have imaged what may be water vapour plumes erupting 125 miles (200 kilometres) off the surface of Jupiter’s moon Europa. Europa has a huge global ocean containing twice as much water as Earth’s oceans, but it is protected by a layer of extremely cold and hard ice of unknown thickness.
Now just one month away from entering into orbit around Ceres, NASA’s Dawn spacecraft reveals new pictures and a movie — the sharpest images to date of the Texas-sized dwarf planet.
The first colour images of Pluto’s atmospheric hazes returned by NASA’s New Horizons spacecraft last week — seen here backlit by the Sun — reveal that the hazes are blue. Also, in a second significant finding, New Horizons has detected numerous small, exposed regions of water ice on the dwarf planet.