Imperial College London
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ProfessorSamuelKounaves

Faculty of Engineering, Department of Earth Science & Engineering

Visiting Professor
 
 
 
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Contact

 

+44 (0)7763 262 356s.kounaves Website CV

 
 
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Location

 

2.34Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@inbook{Kounaves:2018,
author = {Kounaves, S and Oberlin, E},
booktitle = {Volatiles in the Martian Crust},
editor = {Filiberto and Schwenzer},
publisher = {Elsevier},
title = {Volatiles Measured by the Phoenix Lander at the Northern Plains of Mars},
url = {http://planetary.chem.tufts.edu/index.html},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - CHAP
AB  - The science goals of the Phoenix lander were to verify near-surface H2O ice surrounding the north polar cap, characterize the shallow icy soil and overlying soil deposits, document the high latitude surface and atmospheric environments, and evaluate the habitability. These goals guided payload selection which included; the Thermal and Evolved Gas Analyzer (TEGA), consisting of eight differential scanning calorimetry (DSC) cells coupled to a magnetic-sector mass spec (MS) for identification and quantification of organics and inorganics in the atmosphere and minerals; the Wet Chemistry Laboratory (WCL) to analyze the soil chemistry at the surface and depth to better understand the history of the water, habitability, chemical energy sources, and the general geochemistry including  SO42-, Cl-, Br-, I-, NO3-, and ClO4-; and the Thermal and Electrical Conductivity Probe (TECP), mounted near the end of the 2.3 m Robotic Arm (RA), to characterize, control, distribution, and exchange of H2O between the atmosphere and subsurface.  These instruments provided a wealth of data about volatiles, especially, sulfur, carbon, chlorine, and water.  A significant discovery was that the dominant chlorine (Cl)  phase in the soil was perchlorate (ClO4-) at ~ 0.6 wt% at a ratio of ClO4- to Cl- of 6:1. The production of ClO4- on Cl-mineral surfaces would result in highly oxidizing intermediates (ClO-, ClO2, •OCl, •Cl, •OH), capable of destroying or altering organics. Results also showed that the soil contained a 3:2 ratio of Ca(ClO4)2 to Mg(ClO4)2, strongly supporting the conclusion that the Phoenix site has been extremely arid for at least ~ 600 Myr. Other results included; ~ 1.3 wt% SO42-, most likely as a hydrated MgSO4, limiting the S phases to predominantly insoluble sulfur compounds; isotopic composition for atmospheric CO2 of δ13CVPDB = -2.5 ± 4.3‰ and δ18OVSMOW = 31.0 ±5.7‰, notably lacking in 13C; and calcium rich carbonate pha
AU  - Kounaves,S
AU  - Oberlin,E
PB  - Elsevier
PY  - 2018///
SN  - 9780128041918
TI  - Volatiles Measured by the Phoenix Lander at the Northern Plains of Mars
T1  - Volatiles in the Martian Crust
UR  - http://planetary.chem.tufts.edu/index.html
ER  -
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