NASA's MAVEN gets unprecedented look at Mars' upper atmosphere

It observed a storm of energetic solar particles at Mars, produced unprecedented ultraviolet images of the tenuous oxygen, hydrogen, and carbon coronas surrounding the Red Planet, and yielded a comprehensive map of highly-variable ozone in the atmosphere underlying the coronas.

Davin Larson of the Space Sciences Laboratory at the University of California, said that after traveling through interplanetary space, these energetic particles of mostly protons deposit their energy in the upper atmosphere of Mars and a SEP event like this typically occurs every couple weeks.

The hydrogen and oxygen coronas of Mars are the tenuous outer fringe of the planet's upper atmosphere, where the edge of the atmosphere meets space. In this region, atoms that were once a part of carbon dioxide or water molecules near the surface can escape to space.

These molecules control the climate, so following them allowed them to understand the history of Mars over the last four billion years and to track the change from a warm and wet climate to the cold, dry climate that's seen today. MAVEN observed the edges of the Martian atmosphere using the Imaging Ultraviolet Spectrograph (IUVS), which was sensitive to the sunlight reflected by these atoms.

IUVS also created a map of the atmospheric ozone on Mars by detecting the absorption of ultraviolet sunlight by the molecule.

There will be about two weeks of additional instrument calibration and testing before MAVEN starts its primary science mission. This includes an end-to-end test to transmit data between NASA's Curiosity rover on the surface of Mars and Earth using the MAVEN mission's Electra telecommunications relay. The mission aims to start full science gathering in early to mid-November.