The planets in our solar system experience seasons because of the way that they are tilted in their orbits, so one hemisphere is facing the sun more often at some times of year than others. However, there’s another factor which also affects weather and conditions on some planets, which is their position in their orbit around the sun. Earth has a relatively circular orbit, so the differences caused by it being slightly closer or further from the sun at different points are minimal.
This first image was taken during the summer season on the planet’s southern hemisphere when Mars was at its closest point to the sun. The image was taken by MAVEN’s Imaging Ultraviolet Spectrograph instrument, which operates in the ultraviolet wavelength. So to create an image, the values from the instrument have to be shifted into the visible light range.