Mars Spacecraft Reveal Comet Flyby Effects on Martian Atmosphere | NASA

The MAVEN spacecraft, recently arrived at Mars, detected the comet encounter in two ways. The remote-sensing Imaging Ultraviolet Spectrograph observed intense ultraviolet emission from magnesium and iron ions high in the atmosphere in the aftermath of the meteor shower. Not even the most intense meteor storms on Earth have produced as strong a response as this one. The emission dominated Mars’ ultraviolet spectrum for several hours after the encounter and then dissipated over the next two days.

MAVEN also was able to directly sample and determine the composition of some of the comet dust in Mars’ atmosphere. Analysis of these samples by the spacecraft’s Neutral Gas and Ion Mass Spectrometer detected eight different types of metal ions, including sodium, magnesium and iron. These are the first direct measurements of the composition of dust from an Oort Cloud comet.

via Mars Spacecraft Reveal Comet Flyby Effects on Martian Atmosphere | NASA. posted the actual atmosphere spectrum measurements.

MAVEN did not actually see streaks of light in the Martian atmosphere–the spacecraft was sheltering behind the body of Mars during the comet’s flyby. But when MAVEN emerged, it found a glowing layer of Mg+ (a constituent of meteor smoke) floating 150 km above the planet’s surface.

The blue is Mars’ atmosphere before the comet flyby, red is after.

The “smoke” was made of ionized magnesium and other metals shed by the disintegrating meteoroids. The data are consistent with “a few tons of comet dust being deposited in the atmosphere of Mars,” says Nick Schneider, the instrument lead for MAVEN’s Imaging Ultraviolet Spectrograph at University of Colorado, Boulder. “A human on the surface of Mars might have seen thousands of shooting stars per hour, possibly a meteor storm.” He further speculated that the meteor shower would have produced a yellow afterglow in the skies of Mars because the meteor smoke was rich in sodium ions.

How cool is that to have MAVEN arrive in time for the flyby.