Sinton Bands: Evidence for Deuterated Water on Mars. 
The infrared absorption bands observed by Sinton at 2710, 2793, and 2898 cm(-1), in the spectrum of Mars, may be due to gaseous D(2)O and HDO in the Martian atmosphere.  The implication would be that the deuterium: hydrogen ratio exceeds that on Earth, presumably because of escape of the lighter gases from Mars, with accompanying gravitational fractionation of the hydrogen isotopes.