Comet Put Magnesium and Iron into Martian Atmosphere
Comet Put Magnesium and Iron into Martian Atmosphere
The places where the red line on this graph extends higher than the blue line show detection of metals added to the Martian atmosphere from dust particles released by a passing comet. The graphed data are from the Imaging Ultraviolet Spectrograph (IUVS) on NASA’s MAVEN spacecraft, which recorded the intensities of emission by ingredients in the Martian atmosphere just before (blue line) and after (red line) comet C/2013 A1 Siding Spring sped within about 87,000 miles (139,500 kilometers) of Mars on Oct. 19, 2014. The “before” line records the usual main gases in the atmosphere, primarily carbon dioxide and its byproducts. The “after” line includes those plus peaks at 280 nanometer wavelength — a fingerprint of ionized magnesium — and other wavelengths that are fingerprints of iron. Researchers interpret this change as a result of vaporization of dust particles that came from the comet and entered the Martian atmosphere at high speed. IUVS uses limb scans to map the chemical makeup and vertical structure across Mars’ upper atmosphere. (Courtesy NASA/University of Colorado Boulder/LASP)
