NASA’s MAVEN (Mars Atmosphere and Volatile EvolutioN) mission has captured breathtaking new ultraviolet images of Mars. These images, taken at different points along Mars’ orbit around the Sun, offer unprecedented insights into the planet’s atmosphere and surface features.
By using ultraviolet wavelengths, MAVEN scientists have unlocked a new perspective on the Martian landscape. The Imaging Ultraviolet Spectrograph (IUVS) instrument, a key component of the MAVEN mission, obtained these global views of Mars in 2022 and 2023, when the planet was positioned near opposite ends of its elliptical orbit.
The IUVS instrument generates false-colour images to render these wavelengths visible to the human eye. In this rendering, the varying brightness levels of three ultraviolet wavelength ranges are represented as red, green, and blue.
This colour scheme unveils intriguing details of the Martian atmosphere, with atmospheric ozone appearing as purple while clouds and hazes take on a white or blue hue. The surface of Mars can appear tan or green, depending on the optimization of the images to enhance contrast and detail.
The first of these images was captured in July 2022 and showcases the southern hemisphere of Mars during its summer season. The tilt of Mars’ rotational axis drives these seasonal differences, similar to the changing seasons experienced on Earth.
The image reveals Argyre Basin, one of Mars’ deepest craters, filled with atmospheric haze depicted as pale pink. At the top left, the deep canyons of Valles Marineris emerge, covered in clouds that appear tan in this image. The southern polar ice cap, seen at the bottom in white, undergoes shrinkage due to the relative warmth of summer.
Moving to the second image, taken in January 2023, we can see Mars’ northern hemisphere after reaching the farthest point in its orbit from the Sun. The rapid changes in seasons within the north-polar region result in abundant white clouds. As seen in the image, the deep canyons of Valles Marineris are portrayed in tan at the lower left, accompanied by numerous craters.
In this UV view, ozone appears magenta and has built up during the cold polar nights of the northern winter. However, chemical reactions with water vapour, restricted to lower atmospheric altitudes, lead to ozone destruction as the northern spring arrives.
The MAVEN mission launched in November 2013 and entered Mars’ orbit in September 2014. It has been dedicated to exploring the planet’s upper atmosphere, ionosphere, and its interactions with the Sun and solar wind.
By studying the loss of the Martian atmosphere into space, scientists aim to gain valuable insights into the history of Mars’s atmosphere, climate, liquid water, and potential for habitability.
As MAVEN approaches its 10th year at Mars in September 2024, the team behind the mission is gearing up to celebrate a decade of groundbreaking discoveries.