NASA has published photos that show Mars in July 2022 and January 2023 in ultraviolet light.
The technique used by the space agency measures wavelengths between 110 and 3340 nanometers – which is obviously outside the visible spectrum. The purple areas are the ozone in the Red Planet's atmosphere, while the white and blue are clouds and haze in the sky.
"By viewing the planet in ultraviolet wavelengths, scientists can gain insight into the Martian atmosphere and view surface features in remarkable ways," NASA stated.
Mars also experiences four different seasons, however, they are twice as long as those on Earth since the Martian year equals approximately two Terran years. The photo taken in July 2022 shows summer on the Red Planet's southern hemisphere – the period when Mars was closest to Sun. On the photo, Argyre Planitia – one of the planet's biggest asteroid-made basins filled with atmospheric haze – and cloudy Valles Marineris can be seen.
The second photo shows the Martian northern hemisphere experiencing winter. This explains the abundance of white clouds and an accumulation of ozone on its North Pole (purple).
According to NASA scientists, the data received alongside the photos enhances the understanding of Martian climate history.