Infrared Photos Show the Difference Between Winter and Summer on Mars

Mars Infrared

The Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter has captured some incredible ultraviolet images of the Red Planet taken at two different points along its orbit around the Sun.

MAVEN entered orbit around Mars on September 21, 2014 and was the first spacecraft dedicated to exploring the upper atmosphere of the planet. NASA has just released two infrared photos that were captured by the orbiter, one which was captured last year and one taken more recently this year. The photos represent captures at near opposites of Mars’s elliptical orbit.

“By viewing the planet in ultraviolet wavelengths, scientists can gain insight into the Martian atmosphere and view surface features in remarkable ways,” NASA explains.

The two images were taken by MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument which measures wavelengths between 110 and 340 nanometers, which is outside the visible spectrum.

“To make these wavelengths visible to the human eye and easier to interpret, the images are rendered with the varying brightness levels of three ultraviolet wavelength ranges represented as red, green, and blue,” NASA says.

“In this color scheme, atmospheric ozone appears purple, while clouds and hazes appear white or blue. The surface can appear tan or green, depending on how the images have been optimized to increase contrast and show detail.”

The first image, below, was captured in July 2022 during Mars’s southern hemisphere’s summer season, which coincides with the planet’s closest point to the Sun. Similar to how seasons work on Earth, the summer on Mars is caused by a tilt in the Red Planet’s rotational axis.

Mars Infrared

“Argyre Basin, one of Mars’ deepest craters, appears at bottom left filled with atmospheric haze (depicted here as pale pink),” NASA writes, explaining the image above. “The deep canyons of Valles Marineris appear at top left filled with clouds (colored tan in this image). The southern polar ice cap is visible at bottom in white, shrinking from the relative warmth of summer. Southern summer warming and dust storms drive water vapor to very high altitudes, explaining MAVEN’s discovery of enhanced hydrogen loss from Mars at this time of year.”

The second image, below, was taken this past January at a time when Mars had passed its farthest point in its orbit of the Sun.

Mars Infrared

“The rapidly changing seasons in the north polar region cause an abundance of white clouds. The deep canyons of Valles Marineris can be seen in tan at lower left, along with many craters. Ozone, which appears magenta in this UV view, has built up during the northern winter’s chilly polar nights. It is then destroyed in northern spring by chemical reactions with water vapor, which is restricted to low altitudes of the atmosphere at this time of year,” NASA explains.

MAVEN will continue its observations of Mars and the team is preparing to celebrate the orbiter’s 10th year in the Red Planet’s orbit in September of next year.

Image Credits: NASA/LASP/CU Boulder