Nearly two years after its historic encounter with Pluto, the New Horizon’s probe has sent back detailed images of the dwarf planet’s thin atmosphere.
With the Sun eclipsed by Pluto, the probe captured the new image using its black-and-white Long Range Reconnaissance Imager (LORRI) and color Ralph/Multispectral Visible Imaging Camera (MVIC). Back on Earth, the imaging team compiled the mosaic, piecing together six images from the LORRI and colorizing them using data from the MVIC.
The bluish haze is likely smog, the result of sunlight blasting the atmosphere’s methane and transforming a portion of it into acetylene and ethylene, which here on Earth are used for welding and fruit ripening, respectively.
If you look closely, you’ll also see distinct bands in the 120-mile-thick haze. Those are not an artifact of the imaging sensors, but rather the result of the atmosphere’s chemistry. Here’s Simon Porter, a postdoc on the New Horizons team, commenting at Ars Technica:
It’s caused different long-chain hydrocarbons condensing out at different pressure/temperature levels. We actually see the same thing in the upper levels of Titan’s atmosphere (which is also mostly-N2 with lots of complex organic chemistry).
Even closer scrutiny reveals Pluto’s rugged terrain.
New Horizons is now embarking on its extended mission, which will take it past a variety of Kuiper belt objects, which orbit the Sun in a massive disc of space beyond Neptune.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute