Scientists have released a stunning new “farewell to Pluto” image, taken by NASA's New Horizons spacecraft as it flew past Pluto on July 14, 2015.
Once on the night side of the dwarf planet, the spacecraft pointed its camera back at Pluto to observe the Sun’s light coming through its atmosphere. While we’ve seen what this looked like before, this glorious high-resolution image reveals even more details.
“This is the highest-resolution color departure shot of Pluto's receding crescent from NASA's New Horizons spacecraft, taken when the spacecraft was 120,000 miles (200,000 kilometers) away from Pluto,” the New Horizons team said in a statement.
“Shown in approximate true color, the picture was constructed from a mosaic of six black-and-white images from the Long Range Reconnaissance Imager (LORRI), with color added from a lower resolution Ralph/Multispectral Visible Imaging Camera (MVIC) color image.”
The image was taken about 3.5 hours after New Horizons passes its closest point to Jupiter, with a resolution of about 1 kilometer (0.6 miles) per pixel. This image was stitched together by astronomers Alex Parker and Tod Lauer.
As you can see, Pluto appears to have a blue haze not wholly dissimilar to Earth. In Pluto’s case, this is thought to be made by a photochemical smog resulting from sunlight acting on methane and other molecules. This produces a mixture of hydrocarbons, which then scatter more blue light than other light. Layers of this haze reach up to 200 kilometers (120 miles) above the surface.
But perhaps the most amazing feature of this image is the black streaks you can just make out around the upper rim of the dwarf planet. These are shadows from mountains lit by the Sun behind, which you can also just make out on the horizon. Yes, that is really, really awesome.
Most of the data from the Pluto flyby has now been downloaded, with New Horizons now on its way to visit another object in the Kuiper Belt on New Years’ Day 2019. Images like this, though, remind us just how special that Pluto flyby was.