Paul Mahaffy is an Emeritus Scientist in the Solar System Exploration Division at NASA Goddard. He has participated for many years at Goddard Space Flight Center in study of planetary atmospheres and development of space qualified instrumentation. His main research interests are: (1) Planetary science, especially chemical and isotopic composition of planetary atmospheres and comets, (2) Advanced instrument development for organic and light isotope analysis in planetary targets, and (3) Analog studies for martian and cometary materials including both laboratory and field work.
Paul R Mahaffy
(DIR, SOLAR SYSTEM EXPLORATION DIV)
| Email: | paul.r.mahaffy@nasa.gov |
| Phone: | 301.614.6379 |
| Org Code: | 690 |
| Address: |
NASA/GSFC Mail Code 690 Greenbelt, MD 20771 |
| Employer: | EMERITUS |
Brief Bio
Research Interests
Mass Spectrometer Projects
Solar System: Solar SystemMission participation
Paul Mahaffy served until his retirement in December 2021 as the Principal Investigator (PI) on the Sample Analysis at Mars Instrument Suite on the Curiosity Rover currently operating on the surface of Mars as well as the PI on the Neutral Gas and Ion Mass Spectrometer on the MAVEN Mars orbiter mission, and the PI on the Neutral Mass Spectrometer on the LADEE mission that recently finished a very successful mission in lunar orbit exploring the tenuous lunar exosphere. One of his past career highlights was studying the atmosphere of Jupiter using data from a mass spectrometer on the Galileo Probe as it parachuted down into that atmosphere and sent its data back to Earth.
Recent refereed publications
P.R. Mahaffy and 26 CoAuthors, The imprint of atmospheric evolution in the D/H of Hesperian clay minerals on Mars, Science 23, 412-414 (2015).
P.R. Mahaffy and P. Conrad, Volatile and Isotopic Imprints of Ancient Mars, Elements 11, 51 (2015).
C.R. Webster, P.R. Mahaffy and 29 CoAuthors, Mars methane detection and variability at Gale crater, Science 23, 415-417 (2015).
C. Freissinet, D. Glavin, P.R. Mahaffy and other CoAuthors, Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars, accepted, Journal of Geophysical Research (2015).
H. Franz and several CoAuthors including P.R. Mahaffy, Reevaluated Martian Atmospheric Mixing Ratios from the Mass Spectrometer on the Curiosity Rover, accepted Planetary and Space Science (2015).
J. Stern and several CoAuthors including P.R. Mahaffy, Evidence for indigenous nitrogen in sedimentary and aeolian deposits from the Curiosity rover, accepted, Journal of the National Academy of Sciences (2015).
Y. Chen, P. Mahaffy, V. Holmes, J. Burris, P. Morey, K.K. Lehmann, B Sherwood Lollar, G. Lacrampe-Couloume, T.C. Onstott, Near infrared cavity ring-down spectroscopy for isotopic analyses of CH4 on future Martian surface missions, Planetary and Space Science 105, 117 (2015).
R.C. Elphic, G.T. Delory, B. Hine, P.R. Mahaffy, M. Horanyi, A. Colaprete, M. Benna, S.K. Noble, The Lunar Atmosphere and Dust Environment Explorer Mission, Space Science Review, 185, 3, (2015).
H. Franz and several CoAuthors including P.R. Mahaffy, Analytical Techniques for Retrieval of Atmospheric Composition with the Quadrupole Mass Spectrometer of the Sample Analysis at Mars Instrument Suite on Mars Science Laboratory, accepted by Planetary and Space Sciences (2014).
P.R. Mahaffy and 35 CoAuthors, The Neutral Gas and Ion Mass Spectrometer on the Mars Atmosphere and Volatile Evolution Mission, Space Science Reviews, DOI 10.1007/s11214-014-0091-1 (2014).
P.R. Mahaffy and 35 CoAuthors, The Neutral Mass Spectrometer on the Lunar Atmosphere and Dust Environment Explorer Mission, DOI: 10.1007/s11214-014-0043-9 (2014).
McAdam, Amy C.; Franz, Heather B.; Sutter, Brad; Archer, Paul D.; Freissinet, Caroline; Eigenbrode, Jennifer L.; Ming, Douglas W.; Atreya, Sushil K.; Bish, David L.; Blake, David F.; Bower, Hannah E.; Brunner, Anna; Buch, Arnaud; Glavin, Daniel P.; Grotzinger, John P.; Mahaffy, Paul R.; McLennan, Scott M.; Morris, Richard V.; Navarro-González, Rafael; Rampe, Elizabeth B.; Squyres, Steven W.; Steele, Andrew; Stern, Jennifer C.; Sumner, Dawn Y.; Wray, James J., Sulfur-bearing phases detected by evolved gas analysis of the Rocknest aeolian deposit, Gale Crater, Mars, Journal of Geophysical Research: Planets, 119, 373 (2014).
Paul D. Archer, Heather B. Franz, Brad Sutter, Ricardo D. Arevalo Jr., Patrice Coll, Jennifer L. Eigenbrode, Alberto G. Fairen, Daniel P. Glavin, John J. Jones, Laurie A. Leshin, Paul R. Mahaffy, Amy C. McAdam, Christopher P. McKay, Douglas W. Ming, Richard V. Morris, Rafael Navarro-Gonzalez, Paul B. Niles, Alex Pavlov, Steven W. Squyres, Jennifer Claire Stern, Andrew Steele, James J. Wray, Abundances and implications of volatile-bearing species from Evolved Gas Analysis of the Rocknest aeolian bedform, Gale Crater, Mars, JGR Planets, 119, 237 (2014).
Pavlov, A. A., Pavlov, A. K., Ostryakov, V. M., Vasilyev, G. I., Mahaffy, P., & Steele, A. (2014). Alteration of the carbon and nitrogen isotopic composition in the Martian surface rocks due to cosmic ray exposure. Journal of Geophysical Research (Planets), 119, 1390-1402.
Paul R. Mahaffy, Christopher R. Webster, Sushil K. Atreya, Heather Franz, Michael Wong, Pamela G. Conrad, Dan Harpold, John J. Jones, Laurie A. Leshin, Heidi Manning, Tobias Owen, Robert O. Pepin, Steven Squyres, Melissa Trainer and the MSL Science Team, Abundance and Isotopic Composition of Gases in the Martian Atmosphere from the Curiosity Rover, Science 343 (2013).
J. P. Grotzinger, D. Y. Sumner, L. C. Kah, K. Stack, S. Gupta, L. Edgar, D. Rubin, K. Lewis, J. Schieber, N. Mangold, R. Milliken, P. G. Conrad, D. DesMarais, J. Farmer, K. Siebach, F. Calef, J. Hurowitz, S. M. McLennan, D. Ming, D. Vaniman, J. Crisp, A. Vasavada, K. S. Edgett, M. Malin, D. Blake, R. Gellert, P. Mahaffy, R. C. Wiens, S. Maurice, J. A. Grant, S. Wilson, R. C. Anderson, L. Beegle, R. Arvidson, B. Hallet, R. S. Sletten, M. Rice, J. Bell, J. Griffes, B. Ehlmann, R. B. Anderson, T. F. Bristow, W. E. Dietrich, G. Dromart, J. Eigenbrode, A. Fraeman, C. Hardgrove, K. Herkenhoff, L. Jandura, G. Kocurek, S. Lee, L. A. Leshin, R. Leveille, D. Limonadi, J. Maki, S. McCloskey, M. Meyer, M. Minitti, H. Newsom, D. Oehler, A. Okon, M. Palucis, T. Parker, S. Rowland, M. Schmidt, S. Squyres, A. Steele, E. Stolper, R. Summons, A. Treiman, R. Williams, A. Yingst, M. S. Team, A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars. Science, (December 9, 2013, 2013).
D. W. A. Ming, P.D; Glavin,D.P.; Eigenbrode,J.L.;Franz,H.B.; Sutter,B.; Brunner,A.E.;Stern,J.C.; Freissinet,C.; McAdam,A.C.; Mahaffy,P.R.; Cabane,M.; Coll,P.; Campbell,J.L.; Atreya,S.K.; Niles,P.B.; Bell,J.F.; Bish,D.L.; Brinckerhoff,W.B.; Buch,A.; Conrad,P.G.; Des Marais,D.J.; Ehlmann,B.L.;Fairén,A.G.; Farley,K.; Flesch,G.J.; Francois,P.; Gellert,R.; Grant,J.A.; Grotzinger,J.P.; Gupta,S.; Herkenhoff,K.E.; Hurowitz,J.A.; Leshin,L.A.; Lewis,K.W.; McLennan,S.M.; Miller,K.E.; Moersch,J.; Morris,R.V.; Navarro-González,R.; Pavlov,A.A.; Perrett,G.M.; Pradler,I.; Squyres,S.W.; Summons,R.E.; Steele,A.; Stolper,E.M.; Sumner,D.Y.; Szopa,C.; Teinturier,S.; Trainer,M.G.; Treiman,A.H.; Vaniman,D.T.; Vasavada,A.R.; Webster,C.R.; Wray,J.J.; Yingst,R.A.; MSL Science Team., Volatile and Organic Compositions of Sedimentary Rocks in Yellowknife Bay, Gale crater, Mars. Science Express 342, (2013).
Atreya, Sushil K.; Trainer, Melissa G.; Franz, Heather B.; Wong, Michael H.; Manning, Heidi L. K.; Malespin, Charles A.; Mahaffy, Paul R.; Conrad, Pamela G.; Brunner, Anna E.; Leshin, Laurie A.; Jones, John H.; Webster, Christopher R.; Owen, Tobias C.; Pepin, Robert O.; Navarro-González, R., Primordial argon isotope fractionation in the atmosphere of Mars measured by the SAM instrument on Curiosity and implications for atmospheric loss, Geophysical Research Letters, 40, 5605-5609 (2013).
Wong, M.H., S.K. Atreya, P.N. Mahaffy, H.B. Franz, C. Malespin, M.G. Trainer, P.G. Conrad, H.L.K. Manning, R.O. Pepin, R.H. Becker, C.P. McKay, T.C. Owen, R. Navarro-González, J.H. Jones, B.M. Jakosky, A. Steele (2013) Isotopes of nitrogen on Mars: Atmospheric measurements by Curiosity's mass spectrometer. Geophysical Research Letters, in press, DOI: 10.1002/2013GL057840.
K. A. M. Farley, C.; Mahaffy, P.; Grotzinger, J.; Vasconcelos,P.; Milliken, R.; Malin, M.; Edgett, K.; Pavlov,A.; Jurowitz, J.; Grant, J.; Miller, H.; Arvidson, R.; Beegle, L.; Calef, F.; Conrad, P.; Eietrich, W.E.; Eigenbrode, J.; Gellert, R.; Gupta, S.; Hamilton, V.; Hassler, D.; Lewis, K.; McLennan, S.; Ming, D.; Navarro-Gonzalez, R.;Schwenzer, S.; Stolper, E.;Sumner, D.; Vaniman, D.; Vasavada, A.; Williford, K.; Wimmer-Schweingruber, R.F.; MSL Science Team, In-situ Radiometric and Exposure age Dating of the Martian surface. Science Magazine 342, (2013).
Sittler, E. C.; Cooper, J. F.; Hartle, R. E.; Paterson, W. R.; Christian, E. R.; Lipatov, A. S.; Mahaffy, P. R.; Paschalidis, N. P.; Coplan, M. A.; Cassidy, T. A.; Richardson, J. D.; Fegley, B.; Andre, N., Plasma ion composition measurements for Europa, Planetary and Space Science 88, 26-41 (2013).
C. R. M. Webster, P.R.; Flesch, G.J.; Niles, P.B.; Jones, J.H.; Leshin, L.A.; Atreya, S.K.; Stern, J.; Christensen, L.C.; Owen, T.; Franz, H.; Pepin, R.O.; Steele, A.; MSL Science Team, Isotope Ratios of H, C, and O in CO2 and H2O of the Martian Atmosphere. Science 341, 3 (2013).
L.A. Leshin, P.R. Mahaffy, C.R. Webster, M. Cabane, P. Coll, P.G. Conrad, P.D. Archer, Jr., S.K. Atreya, A.E. Brunner, A. Buch, J.L. Eigenbrode, G.J. Flesch, H.B. Franz, C. Freissinet, D.P. Glavin, A.C. McAdam, K.E. Miller, D.W. Ming, R.V. Morris, R. Navarro-González, P.B. Niles, T. Owen, R.O. Pepin, S. Squyres, A. Steele, J.C. Stern, R.E. Summons, D. Sumner, B. Sutter, C. Szopa, S. Teinturier, M.G. Trainer, J.J. Wray, J.P. Grotzinger and the MSL Science Team, Volatile, Isotope and Organic Analysis of Martian Fines with the Mars Curiosity Rover, Science, 341, id. 1238937 (2013).
Daniel P. Glavin, Caroline Freissinet, Kristen E. Miller, Jennifer L. Eigenbrode, Anna E. Brunner, Arnaud Buch, Brad Sutter, Doug P. Archer, Jr., Sushil K. Atreya, William B. Brinckerhoff, Michel Cabane, Patrice Coll, Pamela G. Conrad, David Coscia, Jason P. Dworkin, Heather B. Franz, John P. Grotzinger, Laurie A. Leshin, Mildred G. Martin, Christopher McKay, Douglas W. Ming, Rafael Navarro-González, Alexander Pavlov, Andrew Steele, Roger E. Summons, Cyril Szopa, Samuel Teinturier, and Paul R. Mahaffy, JGR Planets, final revisions submitted July 2013.
Chris R. Webster, Paul R. Mahaffy, Sushil K. Atreya, Gregory J. Flesch, Kenneth A. Farley, and the MSL Science Team, Low Upper Limit to Methane Abundance on Mars. Science 342, 355 (2013)Doi 10.1126/Science.1242902.
Bishop, Janice L., Franz, Heather B., Goetz, Walter, Blake, David F., Freissinet, Caroline, Steininger, Harald, Goesmann, Fred, Brinckerhoff, William B., Getty, Stephanie, Pinnick, Veronica T., Mahaffy, Paul R., Dyar, M. Darby, Coordinated analyses of Antarctic sediments as Mars analog materials using reflectance spectroscopy and current flight-like instruments for CheMin, SAM and MOMA, Icarus, 224, 309-325 (2013).
D. F. Blake, R. V. Morris, G. Kocurek, S. M. Morrison, R. T. Downs, D. Bish, D. W. Ming, K. S. Edgett, D. Rubin, W. Goetz, M. B. Madsen, R. Sullivan, R. Gellert, I. Campbell, A. H. Treiman, S.M. McLennan, A. S. Yen, J. Grotzinger, D. T. Vaniman, S. J. Chipera, C. N. Achilles, E. B. Rampe, D. Sumner, P-Y Meslin, S. Maurice, O. Forni1, O. Gasnault, M. Fisk, M. Schmidt, P. Mahaffy, L. A. Leshin, D. Glavin, A. Steele, C. Freissinet, R. Navarro-González, R. A. Yingst, L. C. Kah, N. Bridges, K. W. Lewis,T. F. Bristow, J. D. Farmer, J. A. Crisp, E. M. Stolper, D. J. Des Marais, P. Sarrazin and the MSL Science Team, Curiosity at Gale crater, Mars: Characterization and analysis of the Rocknest sand shadow, Science, accepted (2013).
Stern, Jennifer C.; McAdam, Amy C.; Ten Kate, Inge L.; Bish, David L.; Blake, David F.; Morris, Richard V.; Bowden, Roxane; Fogel, Marilyn L.; Glamoclija, Mihaela; Mahaffy, Paul R.; Steele, Andrew; Amundsen, Hans E. F., Isotopic and geochemical investigation of two distinct Mars analog environments using evolved gas techniques in Svalbard, Norway, Icarus, 224, 297-308 (2013).
Heather B. Franz, Melissa G. Trainer, Michael H. Wong, Heidi L. K. Manning, Jennifer C. Stern, Paul R. Mahaffy, Sushil K. Atreya, Pamela G. Conrad, Dan N. Harpold, Laurie A. Leshin, Charles A. Malespin, Christopher P. McKay,J. Thomas Nolan,Eric Raaen, Analytical Techniques for Retrieval of Atmospheric Gas Abundances and Isotope Ratios Measured by the Quadrupole Mass Spectrometer of the Sample Analysis at Mars Instrument Suite on Mars Science Laboratory, Submitted to Space Science Review (2013).
A. C. McAdam, H. Franz, P. Archer, Jr., C. Freissinet, B. Sutter, J. L. Eigenbrode, Daniel P. Glavin, S. Atreya, D. Bish, D. Blake, H. Bower, A. Brunner, J. Grotzinger, P. R. Mahaffy, D. Ming, R. Morris, R. Navarro-Gonzalez, E. Rampe, S. Squyres, A. Steele, J. Stern, J. Wray, Evidence for sulfur-bearing phases in Martian soil fines from SAM volatile analyses at Rocknest, in preparation for submission to JGR Planets (2013).
Stalport, F.; Glavin, D. P.; Eigenbrode, J. L.; Bish, D.; Blake, D.; Coll, P.; Szopa, C.; Buch, A.; McAdam, A.; Dworkin, J. P.; Mahaffy, P. R.: The influence of mineralogy on recovering organic acids from Mars analogue materials using the derivatization experiment on the Sample Analysis at Mars (SAM) instrument suite. Planet Space Sci 2012, 67, 1-13.
Pavlov, A. A.; Vasilyev, G.; Ostryakov, V. M.; Pavlov, A. K.; Mahaffy, P.: Degradation of the organic molecules in the shallow subsurface of Mars due to irradiation by cosmic rays. Geophys Res Lett 2012, 39, 13202.
P.R. Mahaffy, Christopher R.Webster, Michel Cabane, Pamela G. Conrad, Patrice Coll, Sushil K. Atreya, Robert Arvey, Michael Barciniak, Mehdi Benna, Lora Bleacher,William B. Brinckerhoff, Jennifer L. Eigenbrode, Daniel Carignan, Mark Cascia, Robert A. Chalmers, Jason P. Dworkin, Therese Errigo, Paula Everson, Heather Franz, Rodger Farley, Steven Feng, Gregory Frazier, Caroline Freissinet, Daniel P. Glavin, Daniel N. Harpold, Douglas Hawk,
Vincent Holmes, Christopher S. Johnson, Andrea Jones, Patrick Jordan, James Kellogg, Jesse Lewis, Eric Lyness, Charles A. Malespin, David K. Martin, John Maurer, Amy C. McAdam, Douglas McLennan, Thomas J. Nolan, Marvin Noriega, Alexander A. Pavlov, Benito Prats, Eric Raaen, Oren Sheinman, David Sheppard, James Smith, Jennifer C. Stern, Florence Tan, Melissa Trainer, Douglas W. Ming, Richard V. Morris, John Jones, Cindy Gundersen, Andrew Steele, James Wray, Oliver Botta, Laurie A. Leshin, Tobias Owen, Steve Battel, Bruce M. Jakosky, Heidi Manning, Steven Squyres, Rafael Navarro-González, Christopher P. McKay, Francois Raulin, Robert Sternberg, Arnaud Buch, Paul Sorensen, Robert Kline-Schoder, David Coscia, Cyril Szopa, Samuel Teinturier, Curt Baffes, Jason Feldman, Greg Flesch, Siamak Forouhar, Ray Garcia, Didier Keymeulen, Steve Woodward, Bruce P. Block, Ken Arnett, Ryan Miller, Charles Edmonson, Stephen Gorevan, Erik Mumm, The Sample Analysis at Mars Investigation and Instrument Suite, Space Science Reviews DOI 10.1007/s11214-012-9879-z (2012).
Grotzinger, J. P.; Crisp, J.; Vasavada, A. R.; Anderson, R. C.; Baker, C. J.; Barry, R.; Blake, D. F.; Conrad, P.; Edgett, K. S.; Ferdowski, B.; Gellert, R.; Gilbert, J. B.; Golombek, M.; Gómez-Elvira, J.; Hassler, D. M.; Jandura, L.; Litvak, M.; Mahaffy, P.; Maki, J.; Meyer, M.; Malin, M. C.; Mitrofanov, I.; Simmonds, J. J.; Vaniman, D.; Welch, R. V.; Wiens, R. C.: Mars Science Laboratory Mission and Science Investigation. Space Sci Rev 2012, 170, 5-56.
Conrad, P. G.; Eigenbrode, J. L.; Von der Heydt, M. O.; Mogensen, C. T.; Canham, J.; Harpold, D. N.; Johnson, J.; Errigo, T.; Glavin, D. P.; Mahaffy, P. R.: The Mars Science Laboratory Organic Check Material. Space Sci Rev 2012, 170, 479-501.
S. K. Atreya, O. Witasse, V. F. Chevrier, F. Forget, P. R. Mahaffy, P. B. Price, . . . R. W. Zurek. Methane on Mars: Current observations, interpretation, and future plans Preface. Planetary and Space Science 59(2-3), 133-136 (2011).
Webster, C. R.; Mahaffy, P. R.: Determining the local abundance of Martian methane and itsâ™ 13C/12C and D/H isotopic ratios for comparison with related gas and soil analysis on the 2011 Mars Science Laboratory (MSL) mission. Planet Space Sci 2011, 59, 271-283.
D. H. Atkinson, T. R. Spilker, K. Reh, S. K. Atreya, T. S. Balint, R. Beebe, . . . P. Mahaffy (2010). Exploring Saturn With Shallow Probes. Bulletin of the American Astronomical Society. 42: 1007.
H. L. K. Manning, I. L. Ten Kate, S. J. Battel and P. R. Mahaffy. Electric discharge in the Martian atmosphere, Paschen curves and implications for future missions. Advances in Space Research 46, 1334-1340 (2010).
S. A. Getty, I. L. ten Kate, S. H. Feng, W. B. Brinckerhoff, E. H. Cardiff, V. E. Holmes, . . . P. Mahaffy, D. P. Glavin. Development of an evolved gas-time-of-flight mass spectrometer for the Volatile Analysis by Pyrolysis of Regolith (VAPoR) instrument. International Journal of Mass Spectrometry 295(3), 124-132 (2010).
S. A. Getty, O. Auciello, A. V. Sumant, X. P. Wang, D. P. Glavin and P. R. Mahaffy. Characterization of Nitrogen-Incorporated Ultrananocrystalline Diamond as a Robust Cold Cathode Material. Micro- and Nanotechnology Sensors, Systems, and Applications Ii 7679 (2010).
R. C. Elphic, G. T. Delory, E. J. Grayzeck, A. Colaprete, M. Horanyi, P. Mahaffy, . . . J. S. Salute. The Lunar Atmosphere and Dust Environment Explorer (LADEE): New Mission, Longstanding Questions. LPI Contributions 1595, 22 (2010).
P. R. Mahaffy, Geochemical News, Sample Analysis at Mars: Developing Analytical Tools to Search for a Habitable Environment on the Red Planet 121 (2009).
A. Buch, R. Sternberg, C. Szopa, C. Freissinet a,b, C. Garnier, El J. Bekri,
C. Rodier, R. Navarro-Gonza´lez, F. Raulin, M. Cabane, M. Stambouli, D.P. Glavin, P.R. Mahaffy, Development of a gas chromatography compatible Sample Processing System (SPS) for the in-situ analysis of refractory organic matter in martian soil: preliminary results, Advances in Space Research 43, 143-151 (2009).
Getty, Stephanie A., Li, Mary, Hess, Larry, Costen, Nick, King, Todd T., Roman, Patrick A., Brinckerhoff, William B., Mahaffy, Paul R., “Integration of a carbon nanotube field emission electron gun for a miniaturized time-of-flight mass spectrometer,” Proceedings of the SPIE 7318, 731816 (2009)
Coustenis, A., and many CoAuthors including Mahaffy, P.R., TandEM: Titan and Enceladus mission, Experimental Astronomy: 23(3), 893 (2009).
B. Marty, T. Guillot, A. Coustenis, N. Achilleos, Y. Alibert, S. Asmar, . . . J. Zarnecki. Kronos: exploring the depths of Saturn with probes and remote sensing through an international mission. Experimental Astronomy 23, 947-976 (2009).
Mahaffy, P.R., Exploration of the Habitability of Mars: Development of Analytical Protocols for Measurement of Organic Carbon on the 2009 Mars Science Laboratory, Space Science Reviews, 135, 255 (2008).
Wong, M. H., J.I. Lunine, S.K. Atreya, T. Johnson, P.R. Mahaffy, T. C. Owen, and T. Encrenaz, Oxyten and Other Volatiles in the Giant Planets and Their Satellites, in Reviews in Mineralogy and Geochemistry, Vol 68, 219-246 (2008).
Ten Kate, I.L., Canham, J.S., Conrad, P. G, Errigo, T., Katz, I, and Mahaffy, P.R., Impact of Terrestrial Contamination on Organic Measurements from the Mars Science Laboratory, Astrobiology 8, 571-582 (2008).
Education
PhD. 1977, Iowa State University (Physical Chemistry Major)
B.S. 1972, Dordt College (Cum Laude, Chemistry Major, Mathematics Minor)
B.S. 1972, Dordt College (Cum Laude, Chemistry Major, Mathematics Minor)
Professional Societies
American Society of Mass Spectrometry American Chemical Society American Vacuum Society American Geophysical Union AAA/Division of Planetary Sciences Geochemical Society
1999 - Present
Professional Service
National Research Council Decadal Study Mars Panel (2009-2010)
Instrument Technology Capabilities Roadmap team (2004-2005)
Neptune New Visions Orbiter with Deep Probe Study (2003-2005)
Mars Organic Contamination Science Steering Group (2003-2004) (chair)
Mars Strategic Roadmap Federal Advisory committee (2004-2005)
Entry Probe Working Group (2003, 2003)
Mars Planning Science Synthesis Group (2002,2003)
MIDP Review Panel (2003)
Mars Icy Samples Study Team (2003)
Mars Science Laboratory Project and Science Working Group (2002, 2003)
Planetary Instrument Definition and Development Panel (2002)
Technology Assessment for Solar System Exploration, 2002
New Frontiers Jupiter Mission Assessment (2002)
New Frontiers Comet Nucleus Sample Return Assessment (2002)
Planetary Atmospheres Selection Panel (2001)
Mars Smart Lander Science Definition Team (2001)
Planetary Instrument Selection Panel (1997)
New Millenium Deep Space 1 Science Team Selection Board (1997)
Surveyor Lander Selection Team (1995)
Near Earth Astroid Science Team Selection (1994)
Cassini Ion and Neutral Mass Spectrometer Facility Instrument Definition Team (1991)
Cosmic Dust Collection Facility Review Board (1990)
Instrument Technology Capabilities Roadmap team (2004-2005)
Neptune New Visions Orbiter with Deep Probe Study (2003-2005)
Mars Organic Contamination Science Steering Group (2003-2004) (chair)
Mars Strategic Roadmap Federal Advisory committee (2004-2005)
Entry Probe Working Group (2003, 2003)
Mars Planning Science Synthesis Group (2002,2003)
MIDP Review Panel (2003)
Mars Icy Samples Study Team (2003)
Mars Science Laboratory Project and Science Working Group (2002, 2003)
Planetary Instrument Definition and Development Panel (2002)
Technology Assessment for Solar System Exploration, 2002
New Frontiers Jupiter Mission Assessment (2002)
New Frontiers Comet Nucleus Sample Return Assessment (2002)
Planetary Atmospheres Selection Panel (2001)
Mars Smart Lander Science Definition Team (2001)
Planetary Instrument Selection Panel (1997)
New Millenium Deep Space 1 Science Team Selection Board (1997)
Surveyor Lander Selection Team (1995)
Near Earth Astroid Science Team Selection (1994)
Cassini Ion and Neutral Mass Spectrometer Facility Instrument Definition Team (1991)
Cosmic Dust Collection Facility Review Board (1990)
Awards
John C. Lindsay Memorial Award (2014)
Maryland Chemist of the Year Award (American Chemical Society – 2013)
Robert C. Boumann Award for Mission Success (2011).
Sample Analysis at Mars Experiment Team Award (2010).
IRAD Innovator of the Year Team Award (2007).
New Business Capture Award (2005).
GSFC Special Act Award (2004).
GSFC Special Achievement Award (2000).
Galileo Probe Mass Spectrometer Experiment Team Award (1996)
Galileo Probe Mass Spectrometer Team Centerwide Group Achievement Award (1996)
NASA/Goddard/Laboratory for Atmospheres, Technical Achievement Award (1988)
Galileo Probe Mass Spectrometer, Special Service Award (1990)
Pullman Scholar Award (1968-1972)
Argonne National Laboratory Study Grant Award (1972)
Procter and Gamble Scholarship (1972-1973)
American Chemical Society Outstanding Chemistry Major (1972).
Publications
Refereed
2025. "Diverse Organic Molecules on Mars Revealed by the SAM TMAH Experiment." Nature [Journal Article/Letter]
2024. "Environmental Changes Recorded in Sedimentary Rocks in the Clay-Sulfate Transition Region in Gale Crater, Mars: Results from the Sample Analysis at Mars-Evolved Gas Analysis Instrument onboard the Mars Science Laboratory Curiosity Rover." Journal of Geophysical Research: Planets 129 e2024JE008587 [Full Text] [10.1029/2024JE008587] [Journal Article/Letter]
2024. "Long-chain alkanes preserved in a martian mudstone." PNAS [Journal Article/Letter]
2024. "Overview: ‘The Life Detection Knowledge Base’ Special Issue." Astrobiology [Journal Article/Letter]
2023. "Detection of Short Peptide Biosignatures of Psychrophiles via Laser Desorption Mass Spectrometry." Astrobiology 23 (6): 657–669 [Full Text] [10.1089/ast.2022.0138] [Journal Article/Letter]
2022. "Constraining Alteration Processes Along the Siccar Point Group Unconformity, Gale Crater, Mars: Results from the Sample Analysis at Mars Instrument." Journal of Geophysical Research - Planets 127 (11): e2022JE007387 [10.1029/2022JE007387] [Journal Article/Letter]
2022. "Organic carbon concentrations in 3.5-billion-year-old lacustrine mudstones of Mars." Proceedings of the National Academy of Science 119 (27): e2201139119 [Full Text] [10.1073/pnas.2201139119] [Journal Article/Letter]
2022. "Evolved gas analyses of sedimentary rocks from the Glen Torridon Clay-Bearing Unit, Gale crater, Mars: Results from the Mars Science Laboratory Sample Analysis at Mars Instrument Suite." Journal of Geophysical Research: Planets 127 (9): e2022JE007179 [10.1029/2022JE007179] [Journal Article/Letter]
2022. "Depleted carbon isotope compositions observed at Gale crater, Mars." Proceedings of the National Academy of Sciences 119 (4): e2115651119 [Full Text] [10.1073/pnas.2115651119] [Journal Article/Letter]
2021. "Planetary Mass Spectrometry for Agnostic Life Detection in the Solar System." Frontiers in Astronomy and Space Sciences 8 (173): [Full Text] [10.3389/fspas.2021.755100] [Journal Article/Letter]
2021. "Influence of calcium perchlorate on search for Martian organic compounds with MTBSTFA/DMF derivatization." Astrobiology 21 (9): 1137-1156 [Full Text] [10.1089/ast.2020.2393] [Journal Article/Letter]
2021. "A review of Sample Analysis at Mars-Evolved Gas Analysis (SAM-EGA) laboratory analog work supporting the presence of perchlorates and chlorates in Gale crater, Mars." Minerals 11 (5): [Full Text] [10.3390/min11050475] [Journal Article/Letter]
2021. "Pyrolysis of Oxalate, Acetate, and Perchlorate Mixtures and the Implications for Organic Salts on Mars." Journal of Geophysical Research - Planets 126 (4): e2020JE006803 [Full Text] [10.1029/2020JE006803] [Journal Article/Letter]
2021. "Influence of Calcium Perchlorate on the Search for Organics on Mars with Tetramethylammonium Hydroxide Thermochemolysis." Astrobiology 21 (3): 279-297 [10.1089/ast.2020.2252] [Journal Article/Letter]
2020. "Benzoic Acid as the Preferred Precursor for the Chlorobenzene Detected on Mars: Insights from the Unique Cumberland Analog Investigation." The Planetary Science Journal 1 (2): 41 [10.3847/psj/aba690] [Journal Article/Letter]
2020. "Mars Extant Life: What's Next? Conference Report." Astrobiology 20 (6): 785-814 [Full Text] [10.1089/ast.2020.2237] [Journal Article/Letter]
2020. "Constraints on the Mineralogy and Geochemistry of the Vera Rubin ridge, Gale Crater, Mars, from Mars Science Laboratory Sample Analysis at Mars Evolved Gas Analyses." Journal of Geophysical Research: Planets [Full Text] [10.1029/2019JE006309] [Journal Article/Letter]
2020. "The search for organic compounds with TMAH thermochemolysis: from Earth analyses to space exploration experiments." TrAC Trends in Analytical Chemistry 115896 [Full Text] [10.1016/j.trac.2020.115896] [Journal Article/Letter]
2020. "Indigenous and exogenous organics and surface-atmosphere cycling inferred from carbon and oxygen isotopes at Gale crater." Nature Astronomy 4 526-532 [Full Text] [10.1038/s41550-019-0990-x] [Journal Article/Letter]
2020. "Influence of perchlorate on the search for organics on Mars with TMAH thermochemolysis." Talanta [10.1016/j.talanta.2019.06.076] [Journal Article/Letter]
2020. "Surface temperature trends recorded in thiophene from two impact craters: Chicxulub (Earth) and Gale (Mars)." Advances in Astronomy [Journal Article/Letter]
2019. "Seasonal Variations in Atmospheric Composition as Measured in Gale Crater, Mars." Journal of Geophysical Research: Planets 124 (11): 3000-3024 [10.1029/2019je006175] [Journal Article/Letter]
2019. "MAVEN/NGIMS Thermospheric Neutral Wind Observations: Interpretation Using the M‐GITM General Circulation Model." Journal of Geophysical Research: Planets 2019JE005957 [10.1029/2019je005957] [Journal Article/Letter]
2019. "Global circulation of Mars’ upper atmosphere." Science 366 (6471): 1363-1366 [10.1126/science.aax1553] [Journal Article/Letter]
2019. "Importance of Ambipolar Electric Field in Driving Ion Loss From Mars: Results From a Multifluid MHD Model With the Electron Pressure Equation Included." Journal of Geophysical Research: Space Physics 124 (11): 9040-9057 [10.1029/2019ja027091] [Journal Article/Letter]
2019. "The Methane Diurnal Variation and Microseepage Flux at Gale Crater, Mars as Constrained by the ExoMars Trace Gas Orbiter and Curiosity Observations." Geophysical Research Letters 46 (16): 9430-9438 [10.1029/2019gl083800] [Journal Article/Letter]
2019. "Mars Upper Atmospheric Responses to the 10 September 2017 Solar Flare: A Global, Time‐Dependent Simulation." Geophysical Research Letters 46 (16): 9334-9343 [10.1029/2019gl084515] [Journal Article/Letter]
2019. "Application of TMAH thermochemolysis to the detection of nucleobases: application to the MOMA and SAM space experiment." Talanta 204 802-811 [Full Text] [10.1016/j.talanta.2019.06.076] [Journal Article/Letter]
2019. "Ion‐Neutral Coupling in the Upper Atmosphere of Mars: A Dominant Driver of Topside Ionospheric Structure." Journal of Geophysical Research: Space Physics 124 (5): 3786-3798 [10.1029/2019ja026481] [Journal Article/Letter]
2019. "Recovery of Fatty Acids from Mineralogic Mars Analogs by TMAH Thermochemolysis for the Sample Analysis at Mars Wet Chemistry Experiment on the Curiosity Rover." Astrobiology 19 (4): 522-546 [Full Text] [10.1089/ast.2018.1819] [Journal Article/Letter]
2019. "Mars's Dayside Upper Ionospheric Composition Is Affected by Magnetic Field Conditions." Journal of Geophysical Research: Space Physics 124 2018JA026266 [10.1029/2018ja026266] [Journal Article/Letter]
2019. "First In Situ Evidence of Mars Nonthermal Exosphere." Geophysical Research Letters 46 (8): 4144-4150 [10.1029/2019gl082192] [Journal Article/Letter]
2019. "Lunar soil hydration constrained by exospheric water liberated by meteoroid impacts." Nature Geoscience 12 333-338 [10.1038/s41561-019-0345-3] [Journal Article/Letter]
2019. "Atmospheric Tides at High Latitudes in the Martian Upper Atmosphere Observed by MAVEN and MRO." Journal of Geophysical Research: Space Physics 124 2019JA026601 [10.1029/2019ja026601] [Journal Article/Letter]
2019. "Seasonal Variability of Deuterium in the Upper Atmosphere of Mars." Journal of Geophysical Research: Space Physics 124 (3): 2152-2164 [10.1029/2018ja026244] [Journal Article/Letter]
2018. "Abiotic input of fixed nitrogen by bolide impacts to Gale crater during the Hesperian. Insights from the Mars Science Laboratory." Journal of Geophysical Research-Planets 124 (1): 94-113 [Full Text] [10.1029/2018JE005852] [Journal Article/Letter]
2018. "Variability of Martian Turbopause Altitudes." Journal of Geophysical Research: Planets 123 (11): 2939-2957 [10.1029/2018je005704] [Journal Article/Letter]
2018. "Thermal Structure of the Martian Upper Atmosphere From MAVEN NGIMS." Journal of Geophysical Research: Planets 123 (11): 2842-2867 [10.1029/2018je005559] [Journal Article/Letter]
2018. "Major Volatiles Evolved From Eolian Materials in Gale Crater." Geophysical Research Letters [Full Text] [10.1029/2018gl079059] [Journal Article/Letter]
2018. "Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars." Science 360 (6393): 1096-1101 [Full Text] [10.1126/science.aas9185] [Journal Article/Letter]
2018. "Background levels of methane in Mars’ atmosphere show strong seasonal variations." Science 360 (6393): 1093-1096 [10.1126/science.aaq0131] [Journal Article/Letter]
2018. "Thermospheric Expansion Associated With Dust Increase in the Lower Atmosphere on Mars Observed by MAVEN/NGIMS." Geophysical Research Letters 45 (7): 2901-2910 [10.1002/2018gl077525] [Journal Article/Letter]
2017. "Ion Densities in the Nightside Ionosphere of Mars: Effects of Electron Impact Ionization." Geophysical Research Letters [10.1002/2017gl075431] [Journal Article/Letter]
2017. "Large sulfur isotope fractionations in Martian sediments at Gale crater." Nature Geoscience 10 658–662 [Full Text] [10.1038/ngeo3002] [Journal Article/Letter]
2017. "Evolved Gas Analyses of Sedimentary Rocks and Eolian Sediment in Gale Crater, Mars: Results of the Curiosity Rover's Sample Analysis at Mars (SAM) Instrument from Yellowknife Bay to the Namib Dune." Journal of Geophysical Research: Planets 122 (12): 2574-2609 [Full Text] [10.1002/2016je005225] [Journal Article/Letter]
2017. "Nightside Ionosphere of Mars: Composition, Vertical Structure, and Variability." Journal of Geophysical Research 44 [10.1002/2016JA023508] [Journal Article/Letter]
2017. "The nitrate/(per)chlorate relationship on Mars." Geophysical Research Letters [10.1002/2016gl072199] [Journal Article/Letter]
2016. "Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars." Journal of Geophysical Research: Planets 121 (10): 2176-2192 [10.1002/2016je005017] [Journal Article/Letter]
2016. "In situ measurement of atmospheric krypton and xenon on Mars with Mars Science Laboratory." Earth and Planetary Science Letters 454 1-9 [10.1016/j.epsl.2016.08.028] [Journal Article/Letter]
2016. "Magnesium sulfate as a key mineral for the detection of organic molecules on Mars using pyrolysis." Journal of Geophysical Research: Planets 121 (1): 61-74 [10.1002/2015je004884] [Journal Article/Letter]
2015. "Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars." Journal of Geophysical Research: Planets 120 (3): 495-514 [Full Text] [10.1002/2014JE004737] [Journal Article/Letter]
2015. "Evidence for indigenous nitrogen in sedimentary and aeolian deposits from the Curiosity rover investigations at Gale crater, Mars." Proceedings of National Academy of Science 112 (14): 4245-4250 [Full Text] [10.1073/pnas.1420932112] [Journal Article/Letter]
2015. "Reevaluated martian atmospheric mixing ratios from the mass spectrometer on the Curiosity rover." Planetary and Space Science 109-110 154-158 [doi:10.1016/j.pss.2015.02.014] [Journal Article/Letter]
2015. "Design and Demonstration of the Mars Organic Molecule Analyzer (MOMA) on the ExoMars 2018 Rover." IEEE Aerospace [Journal Article/Letter]
2014. "SAM/MSL Terrestrial Background Spectral Library." NASA Tech Briefs, Software Supplement 23 [Magazine]
2014. "Analytical Techniques for Retrieval of Atmospheric Composition with the Quadrupole Mass Spectrometer of the Sample Analysis at Mars Instrument Suite on Mars Science Laboratory." Planet. Space Sci. [10.1016/j.pss.2014.03.005] [Journal Article/Letter]
2014. "Sulfur-bearing Phases Detected by Evolved Gas Analysis of the Rocknest Aeolian Deposit, Gale Crater." J. Geophys. Res. 119 (2): 373-393 [Full Text] [10.1002/2013JE004518] [Journal Article/Letter]
2014. "Abundances and Implications of Volatile-bearing Species from Evolved Gas Analysis of the Rocknest Aeolian Deposit, Gale Crater, Mars." Journal of Geophysical Research: Planets 119 (1): 237-254 [Full Text] [10.1002/2013JE004493] [Journal Article/Letter]
2013. "Mars Organic Molecule Analyzer (MOMA) Mass Spectrometer for ExoMars 2018 and Beyond." IEEE Aerospace [Proceedings]
2013. "Isotopic and geochemical investigation of two distinct Mars analog environments using evolved gas techniques in Svalbard, Norway." Icarus 224 (2013): 297-308 [Journal Article/Letter]
2013. "Isotopic and Geochemical Investigation of Two Distinct Mars Analog Environments Using Evolved Gas Techniques in Svalbard." Icarus 224 (2013): 297-308 [Journal Article/Letter]
2013. "Isotopic and Geochemical Investigation of Two Distinct Mars Analog Environments Using Evolved Gas Techniques in Svalbard." [Journal Article/Letter]
2013. "Evidence for perchlorates and the origin of chlorinated hydrocarbons detected by SAM at the Rocknest aeolian deposit in Gale Crater." J. Geophys. Res. 118 1955 – 1973 [10.1002/jgre.20144] [Journal Article/Letter]
2013. "Isotopes of Nitrogen on Mars: Atmospheric Measurements by Curiosity's Mass Spectrometer." Geophys. Res. Lett. 40 6033-6037 [10.1002/2013GL057840] [Journal Article/Letter]
2013. "Abundance and Isotopic Composition of Gases in the Martian Atmosphere from the Curiosity Rover." Science 341 (6143): 263-266 [10.1126/science.1237966] [Journal Article/Letter]
2013. "Evidence for Perchlorates and the Origin of Chlorinated Hydrocarbons Detected by SAM at the Rocknest Aeolian Deposit in Gale Crater." J. Geophys. Res. 118 1955-1973. [Journal Article/Letter]
2013. "Primordial Argon Isotope Fractionation in the Atmosphere of Mars Measured by the SAM Instrument on Curiosity and Implications for Atmospheric Loss." Geophys. Res. Lett. 40 5605-5609. [Journal Article/Letter]
2013. "Organics Analyzer for Sampling Icy Surfaces: a Liquid Chromatograph-Mass Spectrometer for Future in situ Small Body Missions." IEEE Aerospace Conference Proceedings [Proceedings]
2012. "The Mars Science Laboratory Organic Check Material." Space Science Reviews 170 (1-4): 479-501 [10.1007/s11214-012-9893-1] [Journal Article/Letter]
2012. "Volatile Analysis by Pyrolysis of Regolith for Planetary Resource Exploration." IEEE Aerospace Conference Proceedings 1-11, 3-10 [Full Text] [10.1109/AERO.2012.6187065] [Proceedings]
2012. "Rapid Assessment of High Value Samples: An AOTF-LDTOF Spectrometer Suite for Planetary Surfaces." IEEE Aerospace Conference Proceedings [10.1109/AERO.2012.6187060] [Proceedings]
2012. "Coordinated analyses of Antarctic sediments as Mars analog materials using reflectance spectroscopy and current flight-like instruments for CheMin, SAM and MOMA." Icarus 224 (2): 309-325 [10.1016/j.icarus.2012.05.014] [Journal Article/Letter]
2011. "Methane on Mars: Current observations, interpretation, and future plans." Planetary and Space Science 59 133 [Full Text] [10.1016/j.pss.2010.10.008] [Journal Article/Letter]
2011. "Determining the local abundance of Martian methane and its' 13C/12C and D/H isotopic ratios for comparison with related gas and soil analysis on the 2011 Mars Science Laboratory (MSL) mission." Planetary and Space Science 59 271 [Full Text] [10.1016/j.pss.2010.08.021] [Journal Article/Letter]
2010. "Development of an evolved gas-time-of-flight mass spectrometer for the Volatile Analysis by Pyrolysis of Regolith (VAPoR) instrument." International Journal of Mass Spectrometry 295 124-132 [Journal Article/Letter]
2009. "TandEM: Titan and Enceladus mission." Experimental Astronomy 23 893 [Full Text] [10.1007/s10686-008-9103-z] [Journal Article/Letter]
2007. "Multi-fluid model of comet 1P/Halley." [Journal Article/Letter]
Non-Refereed
2018. "A universal approach in the search for life at the molecular level." A White Paper in response to the ASTROBIOLOGY SCIENCE STRATEGY FOR THE SEARCH FOR LIFE IN THE UNIVERSE [Other]
2015. "Martian Chlorobenzene Identified by Curiosity in Yellowknife Bay: Evidence for the Preservation of Organics in a Mudstone on Mars ." Lunar and Planetary Science Conference 46 1178- [Proceedings]
2013. "Detection of Organic Constituents Including Chloromethylpropene in the Analyses of the Rocknest Drift by Sample Analysis at Mars (SAM)." 44th Lunar and Planetary Science Conference [Full Text] [Proceedings]
2013. "Fluorocarbon Contamination from the Drill on the Mars Science Laboratory: Potential Science Impact on Detecting Martian Organics by Sample Analysis at Mars (SAM)." 44th Lunar and Planetary Science Conference [Full Text] [Proceedings]
2011. "Thermochemolysis: A New Sample Preparation Approach for the Detection of Organic Components of Complex Macromolecules in Mars Rocks via Gas Chromatography Mass Spectrometry in SAM on MSL." 42nd Lunar and Planetary Science Conference [Full Text] [Proceedings]
2011. "Environmental Signatures for Habitability: What to Measure and How to Rank the Habitability Potential of Mars." Exploring Mars Habitability, Lisbon, Portugal [Full Text] [Proceedings]
2011. "Field characterizaton of the mineralogy and organic chemistry of carbonates from the 2010 Arctic Mars Analog Svalbard Expedition by Evolved Gas Analysis." LPS XLII Abstract #2136 [Proceedings]
2010. "Laboratory Studies of the Liquid Water Content and the Degradation Rates of Organic Biomarkers in the Shallow Martian Subsurface." Astrobiology Science Conference [Proceedings]
2010. "Organic biosignatures and habitat features of near-surface glacial ice in Svalbard." Astrobiology Science Conference 2010 [Full Text] [Proceedings]
2010. "Evolved Gas Analysis and X-ray Diffraction of Carbonate Samples from the 2009 Arctic Mars Analog Svalbard Expedition: Implications for Mineralogical Inferences from the Mars Science Laboratory." 41st Lunar and Planetary Science Conference [Full Text] [Proceedings]