NASA’s MAVEN mission has taken some ultraviolet global images of Mars, revealing previously unseen behavior in the Red Planet’s atmosphere.
The spacecraft was able to obtain the first images of the “nightglow”, the ultraviolet emission of nitric oxide from the night side of Mars. The oxide is carried in the higher parts of the atmosphere, and it has allowed the researchers to study the wind circulation at high altitude.
The nightglow appears to be in splotches and streaks, an indication that the higher layers of the atmosphere are highly irregular, creating uneven winds. This has global consequences. The high-altitude winds control the impact of the changing seasons on the atmosphere.
To study the seasonal variations, the probe looked at the presence of ozone. The chemical is destroyed by water vapor, so it tends to accumulate in the colder regions. MAVEN discovered that the winds inhibit the spread of water vapor, making the ozone last into spring.
MAVEN's image of the Mars night side shows ultraviolet emissions from nitric oxide. The distribution traces the high altitude winds and it is very irregular. NASA/MAVEN/University of Colorado
"MAVEN obtained hundreds of such images in recent months, giving some of the best high-resolution ultraviolet coverage of Mars ever obtained," said Nick Schneider of the Laboratory for Atmospheric and Space Physics at the University of Colorado in a statement.
Schneider is presenting the findings at the joint meeting of the 48th American Astronomical Society Division for Planetary Sciences and 11th European Planetary Science Congress in Pasadena, California.
MAVEN, which stands for Mars Atmosphere and Volatile EvolutioN, was also able to spot how clouds form in the afternoon over Mars’ giant volcanoes, and snapped images of the whole planet.
"MAVEN's elliptical orbit is just right," said Justin Deighan of the University of Colorado, Boulder, who led the observations.
"It rises high enough to take a global picture, but still orbits fast enough to get multiple views as Mars rotates over the course of a day."
MAVEN has been studying the atmosphere and the surface emission of Mars since 2014. It is equipped with an incredible suite of instruments to analyze the tenuous Martian air as well as its magnetic field and how the solar wind interacts with the two.