HiRISE Camera Catches Glimpse of Jarosite Deposit in Noctis Labyrinthus
NASA's Mars Reconnaissance Orbiter has produced some great images over the years.
And this one from Noctis Labyrinthus is no exception.
On November 24, 2015, the HiRISE (High Resolution Imaging Science Experiment ) camera captured a shot of the western edge of an elongated pit in the eastern part of Noctis Labyrinthus, a series of maze-like valleys and collapsed canyon walls on the western end of Valles Marineris.
What is interesting about this picture is the band of light colored soils along the pit's upper wall.
When analyzed by the orbiter's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument, it was clear that the spectra from the deposit indicates the mineral jarosite -- a potassium and iron hydrous sulfate that usually indicates a highly acidic and oxidizing environment.
On Earth, Jarosite can form in iron ore deposits, or from changes iron sulfates experience in and around volcanic vents. And Noctis Labyrinthus is just east of the largest volcanic regions in the solar system -- the Tharsis Montes (Arsia, Pavonis and Ascraeus Mons).
Jarosite has been found at several other locations on Mars -- the Opportunity rover even discovered it at the Meridiani Planum landing site -- indicating that it is a common mineral on the Red Planet.
What's exciting about this image is that the jarosite-bearing deposit could indicate acidic aqueous conditions in the Noctis Labyrinthus -- which would be consistent with this team's theory on the possibility of warm-water lakes on Mars.
It also shows a mantle of finely layered darker-toned material over the Jarosite deposit, but CRISM details did not indicate whether or not this upper darker-toned mantle is hydrated.
They do appear, however, to drape over other, older deposits , suggesting the possibility it may be volcanic ash from ages past.
Which makes this a really cool pic.