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 New Horizons scientists made this false colour image of Pluto using a technique called principal component analysis to highlight the many subtle colour differences between Pluto’s distinct regions. The image data were collected by the spacecraft’s Ralph/MVIC colour camera on 14 July at 11:11 UTC, from a range of 22,000 miles (35,000 kilometres).
New research from North Carolina State University finds that major volcanic activity on the innermost planet most likely ended about 3.5 billion years ago — in stark contrast to the volcanic ages found for Venus, Mars and Earth. These findings add insight into the geological evolution of Mercury and what happens when rocky planets cool and contract.
It is almost five months since New Horizons’ epic encounter with Pluto, but the captured images and data will stream back to Earth across 3 billion miles of interplanetary space for a further 11 months. The first in a series of the best close-ups of the dwarf planet that humans may see for decades have been released, obtained when the spacecraft was just 15 minutes before closest approach during the 14 July flyby.