Thursday, June 02 2022, 16:00
online only
(for the zoom link contact michael.spira@psi.ch, johannes.schlenk@psi.ch or
antonio.coutinho@psi.ch)
Emily Cardarelli, JPL Nasa
Abstract:
The Perseverance rover successfully landed in Jezero crater, Mars on
February 18, 2021 at the Octavia E. Butler landing site and began its
mission to explore and sample an ancient crater lake basin. Principal
goals of the Mars 2020 mission are to characterize the geology and
seeking signs of ancient microbial life on Mars. The Scanning Habitable
Environments with Raman and Luminescence for Organics and Chemicals
(SHERLOC) instrument is a deep UV Raman spectrometer that utilizes a
248.6 nm pulsed laser. Part of SHERLOC is a color camera known as the
Wide Angle Topographic Sensor for Operations and eNgineering (WATSON).
The SHERLOC suite provides coordinated spectroscopic and imaging
capabilities at high spatial resolution (~100 μm), to detect minerals
and organic molecules in microtextural context via resonance Raman and
native fluorescence spectroscopy. SHERLOC enables texture-specific
molecular composition measurements of rock and regolith targets on Mars.
SHERLOC/WATSON results acquired from the Séítah Formation (Fm) of the Jezero crater floor illuminate the organomineral associations and the biosignature preservation potential of these rocks. The identification of primary and secondary mineral phases observed suggests a release of cations from primary ultramafic minerals through aqueous alteration. Co-occurring olivine and Mg-rich carbonate found within abraded targets of the Séítah Fm indicates that the carbonation of olivine occurred within the mineral matrix hosted in a subsurface system. On Earth, carbonates derived from abiotic and biotic reactions preserve biosignatures (i.e. indices of habitability. Fluorescent features (~330 nm) are unique to the Garde and Dourbes abrasion targets, though they are co-located to carbonate signatures solely within Garde -- between the light toned minerals. The limit of detection for Raman is multiple orders of magnitude greater than the limit of detection required for fluorescence and identification of these fluorescent features may be consistent with 1-2 ring aromatic compounds. The formation of carbonates by an aqueous alteration process, such as carbonation of olivine is also consistent with hypotheses for carbonate within the greater regional-olivine bearing unit found within the Séítah Fm, which may represent a high-potential biosignature preserving environment on Mars.
NASA's Mars 2020 Mission and SHERLOC Instrument team member Dr. Emily
Cardarelli outlines how Perseverance has spent its first year on Mars,
and the ways its moving toward key mission objectives, such as seeking
signs of ancient microbial life in the rocks of Jezero.