(NASA / JPL-Caltech)
The team of the New Horizons probe has published an image of Pluto's southern hemisphere, which was hidden at night during a close flight of the device past the dwarf planet.
The researchers found a bright area that could be an accumulation of nitrogen or methane ice.
New Horizons was launched into space in 2006, and in 2015 for the first time in history made a close flyby past Pluto, receiving images of both the dwarf planet and its satellites.
In early 2019, the station approached the Kuiper Belt object Arrocot, receiving detailed images.
Now the device is heading to the borders of the solar system, exploring the environment and other objects in the Kuiper Belt.
While flying past Pluto, New Horizons received detailed images of only the part of Pluto that was well lit.
The station also took pictures of the night side of the planet when it flew away from it, but not so many surface details could be seen on them.
A team of researchers from a team led by Tod Lauer of the NOIRLab (National Optical-Infrared Astronomy Research Laboratory) presented images of the invisible part of Pluto, which was illuminated only by the scattered surface of Pluto's largest moon Charon by sunlight.
At the time of filming, Pluto's southern hemisphere was in winter, similar to the polar night on Earth. The seasons change on a dwarf planet every 62 years.
The final image of the night side of Pluto was compiled from 360 LORRI images of Pluto itself, and another 360 images taken with the same survey geometry, but without Pluto.
This allowed scientists to remove as many artifacts from the image as possible, leaving only the details of Pluto's surface.
In the resulting image, the researchers identified several areas.
It is a dark crescent to the west, where neither sunlight nor light from Charon has fallen, and a large bright area that can be deposits of nitrogen or methane ice.
Scientists also found that the south polar region at the time of the survey had a significantly lower albedo than the north polar region of Pluto, which may be due to the sublimation of nitrogen ice or the deposition of haze particles during the recent summer.
Sources: