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1. Photogeologic Map of the Perseverance Rover Field Site in Jezero Crater Constructed by the Mars 2020 Science Team

Author

Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Stack, Kathryn M., Williams, Nathan R., Calef, Fred, Sun, Vivian Z., Williford, Kenneth H., Farley, Kenneth A., Eide, Sigurd, Flannery, David, Hughes, Cory, Jacob, Samantha R., Kah, Linda C., Meyen, Forrest, Molina, Antonio, Nataf, Cathy Quantin, Rice, Melissa, Russell, Patrick, Scheller, Eva, Seeger, Christina H., Abbey, William J., Adler, Jacob B., Amundsen, Hans, Anderson, Ryan B., Angel, Stanley M., Arana, Gorka, Atkins, James, Barrington, Megan, Berger, Tor, Borden, Rose, Boring, Beau, Brown, Adrian, Carrier, Brandi L., Conrad, Pamela, Dypvik, Henning, Fagents, Sarah A., Gallegos, Zachary E., Garczynski, Brad, Golder, Keenan, Gomez, Felipe, Goreva, Yulia, Gupta, Sanjeev, Hamran, Svein-Erik, Hicks, Taryn, Hinterman, Eric Daniel, Horgan, Briony N., Hurowitz, Joel, Johnson, Jeffrey R., Lasue, Jeremie, Kronyak, Rachel E., Liu, Yang, Madariaga, Juan Manuel, Mangold, Nicolas, McClean, John, Miklusicak, Noah, Nunes, Daniel, Rojas, Corrine, Runyon, Kirby, Schmitz, Nicole, Scudder, Noel, Shaver, Emily, SooHoo, Jason G., Spaulding, Russell, Stanish, Evan, Tamppari, Leslie K., Tice, Michael M., Turenne, Nathalie, Willis, Peter A., Aileen Yingst, R., Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Stack, Kathryn M., Williams, Nathan R., Calef, Fred, Sun, Vivian Z., Williford, Kenneth H., Farley, Kenneth A., Eide, Sigurd, Flannery, David, Hughes, Cory, Jacob, Samantha R., Kah, Linda C., Meyen, Forrest, Molina, Antonio, Nataf, Cathy Quantin, Rice, Melissa, Russell, Patrick, Scheller, Eva, Seeger, Christina H., Abbey, William J., Adler, Jacob B., Amundsen, Hans, Anderson, Ryan B., Angel, Stanley M., Arana, Gorka, Atkins, James, Barrington, Megan, Berger, Tor, Borden, Rose, Boring, Beau, Brown, Adrian, Carrier, Brandi L., Conrad, Pamela, Dypvik, Henning, Fagents, Sarah A., Gallegos, Zachary E., Garczynski, Brad, Golder, Keenan, Gomez, Felipe, Goreva, Yulia, Gupta, Sanjeev, Hamran, Svein-Erik, Hicks, Taryn, Hinterman, Eric Daniel, Horgan, Briony N., Hurowitz, Joel, Johnson, Jeffrey R., Lasue, Jeremie, Kronyak, Rachel E., Liu, Yang, Madariaga, Juan Manuel, Mangold, Nicolas, McClean, John, Miklusicak, Noah, Nunes, Daniel, Rojas, Corrine, Runyon, Kirby, Schmitz, Nicole, Scudder, Noel, Shaver, Emily, SooHoo, Jason G., Spaulding, Russell, Stanish, Evan, Tamppari, Leslie K., Tice, Michael M., Turenne, Nathalie, Willis, Peter A., and Aileen Yingst, R.

Abstract

The Mars 2020 Perseverance rover landing site is located within Jezero crater, a ∼50 km diameter impact crater interpreted to be a Noachian-aged lake basin inside the western edge of the Isidis impact structure. Jezero hosts remnants of a fluvial delta, inlet and outlet valleys, and infill deposits containing diverse carbonate, mafic, and hydrated minerals. Prior to the launch of the Mars 2020 mission, members of the Science Team collaborated to produce a photogeologic map of the Perseverance landing site in Jezero crater. Mapping was performed at a 1:5000 digital map scale using a 25 cm/pixel High Resolution Imaging Science Experiment (HiRISE) orthoimage mosaic base map and a 1 m/pixel HiRISE stereo digital terrain model. Mapped bedrock and surficial units were distinguished by differences in relative brightness, tone, topography, surface texture, and apparent roughness. Mapped bedrock units are generally consistent with those identified in previously published mapping efforts, but this study’s map includes the distribution of surficial deposits and sub-units of the Jezero delta at a higher level of detail than previous studies. This study considers four possible unit correlations to explain the relative age relationships of major units within the map area. Unit correlations include previously published interpretations as well as those that consider more complex interfingering relationships and alternative relative age relationships. The photogeologic map presented here is the foundation for scientific hypothesis development and strategic planning for Perseverance’s exploration of Jezero crater.

Published
2021

2. Photogeologic Map of the Perseverance Rover Field Site in Jezero Crater Constructed by the Mars 2020 Science Team

Author

Stack, Kathryn M., Williams, Nathan R., Calef, Fred, Sun, Vivian Z., Williford, Kenneth H., Farley, Kenneth A., Eide, Sigurd, Flannery, David, Hughes, Cory, Jacob, Samantha R., Kah, Linda C., Meyen, Forrest, Molina, Antonio, Nataf, Cathy Quantin, Rice, Melissa, Russell, Patrick, Scheller, Eva, Seeger, Christina H., Abbey, William J., Adler, Jacob B., Amundsen, Hans, Anderson, Ryan B., Angel, Stanley M., Arana, Gorka, Atkins, James, Barrington, Megan, Berger, Tor, Borden, Rose, Boring, Beau, Brown, Adrian, Carrier, Brandi L., Conrad, Pamela, Dypvik, Henning, Fagents, Sarah A., Gallegos, Zachary E., Garczynski, Brad, Golder, Keenan, Gomez, Felipe, Goreva, Yulia, Gupta, Sanjeev, Hamran, Svein Erik, Hicks, Taryn, Hinterman, Eric D., Horgan, Briony N., Hurowitz, Joel, Johnson, Jeffrey R., Lasue, Jeremie, Kronyak, Rachel E., Liu, Yang, Madariaga, Juan Manuel, Mangold, Nicolas, McClean, John, Miklusicak, Noah, Nunes, Daniel, Rojas, Corrine, Runyon, Kirby, Schmitz, Nicole, Scudder, Noel, Shaver, Emily, SooHoo, Jason, Spaulding, Russell, Stanish, Evan, Tamppari, Leslie K., Tice, Michael M., Turenne, Nathalie, Willis, Peter A., Aileen Yingst, R., Stack, Kathryn M., Williams, Nathan R., Calef, Fred, Sun, Vivian Z., Williford, Kenneth H., Farley, Kenneth A., Eide, Sigurd, Flannery, David, Hughes, Cory, Jacob, Samantha R., Kah, Linda C., Meyen, Forrest, Molina, Antonio, Nataf, Cathy Quantin, Rice, Melissa, Russell, Patrick, Scheller, Eva, Seeger, Christina H., Abbey, William J., Adler, Jacob B., Amundsen, Hans, Anderson, Ryan B., Angel, Stanley M., Arana, Gorka, Atkins, James, Barrington, Megan, Berger, Tor, Borden, Rose, Boring, Beau, Brown, Adrian, Carrier, Brandi L., Conrad, Pamela, Dypvik, Henning, Fagents, Sarah A., Gallegos, Zachary E., Garczynski, Brad, Golder, Keenan, Gomez, Felipe, Goreva, Yulia, Gupta, Sanjeev, Hamran, Svein Erik, Hicks, Taryn, Hinterman, Eric D., Horgan, Briony N., Hurowitz, Joel, Johnson, Jeffrey R., Lasue, Jeremie, Kronyak, Rachel E., Liu, Yang, Madariaga, Juan Manuel, Mangold, Nicolas, McClean, John, Miklusicak, Noah, Nunes, Daniel, Rojas, Corrine, Runyon, Kirby, Schmitz, Nicole, Scudder, Noel, Shaver, Emily, SooHoo, Jason, Spaulding, Russell, Stanish, Evan, Tamppari, Leslie K., Tice, Michael M., Turenne, Nathalie, Willis, Peter A., and Aileen Yingst, R.

Abstract

The Mars 2020 Perseverance rover landing site is located within Jezero crater, a ∼50km diameter impact crater interpreted to be a Noachian-aged lake basin inside the western edge of the Isidis impact structure. Jezero hosts remnants of a fluvial delta, inlet and outlet valleys, and infill deposits containing diverse carbonate, mafic, and hydrated minerals. Prior to the launch of the Mars 2020 mission, members of the Science Team collaborated to produce a photogeologic map of the Perseverance landing site in Jezero crater. Mapping was performed at a 1:5000 digital map scale using a 25 cm/pixel High Resolution Imaging Science Experiment (HiRISE) orthoimage mosaic base map and a 1 m/pixel HiRISE stereo digital terrain model. Mapped bedrock and surficial units were distinguished by differences in relative brightness, tone, topography, surface texture, and apparent roughness. Mapped bedrock units are generally consistent with those identified in previously published mapping efforts, but this study’s map includes the distribution of surficial deposits and sub-units of the Jezero delta at a higher level of detail than previous studies. This study considers four possible unit correlations to explain the relative age relationships of major units within the map area. Unit correlations include previously published interpretations as well as those that consider more complex interfingering relationships and alternative relative age relationships. The photogeologic map presented here is the foundation for scientific hypothesis development and strategic planning for Perseverance’s exploration of Jezero crater.

Published
2020

3. Seasonal Variations in Atmospheric Composition as Measured in Gale Crater, Mars

Author

National Aeronautics and Space Administration (US), Universidad Nacional Autónoma de México, Trainer, Melissa G., Wong, Michael H., McConnochie, Timothy H., Franz, Heather B., Atreya, Sushil K., Conrad, Pamela G., Lefèvre, F., Mahaffy, P.R., Malespin, Charles A., Manning, H. L. K., Martín-Torres, F. J., Martínez, Germán, McKay, Christopher P., Navarro-González, Rafael, Vicente-Retortillo, Álvaro, Webster, Christopher R., Zorzano, María Paz, National Aeronautics and Space Administration (US), Universidad Nacional Autónoma de México, Trainer, Melissa G., Wong, Michael H., McConnochie, Timothy H., Franz, Heather B., Atreya, Sushil K., Conrad, Pamela G., Lefèvre, F., Mahaffy, P.R., Malespin, Charles A., Manning, H. L. K., Martín-Torres, F. J., Martínez, Germán, McKay, Christopher P., Navarro-González, Rafael, Vicente-Retortillo, Álvaro, Webster, Christopher R., and Zorzano, María Paz

Abstract

The Sample Analysis at Mars (SAM) instrument onboard the Mars Science Laboratory Curiosity rover measures the chemical composition of major atmospheric species (CO2, N2, 40Ar, O2, and CO) through a dedicated atmospheric inlet. We report here measurements of volume mixing ratios in Gale Crater using the SAM quadrupole mass spectrometer, obtained over a period of nearly 5 years (3 Mars years) from landing. The observation period spans the northern summer of MY 31 and solar longitude (LS) of 175° through spring of MY 34, LS = 12°. This work expands upon prior reports of the mixing ratios measured by SAM QMS in the first 105 sols of the mission. The SAM QMS atmospheric measurements were taken periodically, with a cumulative coverage of four or five experiments per season on Mars. Major observations include the seasonal cycle of CO2, N2, and Ar, which lags approximately 20¿40° of LS behind the pressure cycle driven by CO2 condensation and sublimation from the winter poles. This seasonal cycle indicates that transport occurs on faster timescales than mixing. The mixing ratio of O2 shows significant seasonal and interannual variability, suggesting an unknown atmospheric or surface process at work. The O2 measurements are compared to several parameters, including dust optical depth and trace CH4 measurements by Curiosity. We derive annual mean volume mixing ratios for the atmosphere in Gale Crater: CO2 = 0.951 (±0.003), N2 = 0.0259 (±0.0006), 40Ar = 0.0194 (±0.0004), O2 = 1.61 (±0.09) x 10-3, and CO = 5.8 (±0.8) x 10-4. ©2019. The Authors.

Published
2019

4. Abiotic Input of Fixed Nitrogen by Bolide Impacts to Gale Crater During the Hesperian: Insights From the Mars Science Laboratory

Author

Universidad Nacional Autónoma de México, Consejo Nacional de Ciencia y Tecnología (México), Navarro-González, Rafael, Navarro, Karina F., Coll, Patrice, McKay, Christopher P., Stern, Jennifer C., Sutter, Brad, Douglas Archer Jr, P., Cabane, Michel, Conrad, Pamela G., Eigenbrode, Jennifer L., Franz, Heather B., Freissinet, Caroline, Glavin, Daniel P., Hogancamp, Joanna V., McAdam, Amy C., Malespin, Charles A., Martín-Torres, F. J., Ming, Douglas W., Morris, Richard V., Prats, Benny, Raulin, François, Rodriguez Manfredi, Jose Antonio, Szopa, Cyril, Zorzano, María Paz, Mahaffy, P.R., Atreya, Sushil, Trainer, Melissa G., Vasavada, Ashwin R., Universidad Nacional Autónoma de México, Consejo Nacional de Ciencia y Tecnología (México), Navarro-González, Rafael, Navarro, Karina F., Coll, Patrice, McKay, Christopher P., Stern, Jennifer C., Sutter, Brad, Douglas Archer Jr, P., Cabane, Michel, Conrad, Pamela G., Eigenbrode, Jennifer L., Franz, Heather B., Freissinet, Caroline, Glavin, Daniel P., Hogancamp, Joanna V., McAdam, Amy C., Malespin, Charles A., Martín-Torres, F. J., Ming, Douglas W., Morris, Richard V., Prats, Benny, Raulin, François, Rodriguez Manfredi, Jose Antonio, Szopa, Cyril, Zorzano, María Paz, Mahaffy, P.R., Atreya, Sushil, Trainer, Melissa G., and Vasavada, Ashwin R.

Abstract

Molecular hydrogen (H2) from volcanic emissions is suggested to warm the Martian surface when carbon dioxide (CO2) levels dropped from the Noachian (4100 to 3700 Myr) to the Hesperian (3700 to 3000 Myr). Its presence is expected to shift the conversion of molecular nitrogen (N2) into different forms of fixed nitrogen (N). Here we present experimental data and theoretical calculations that investigate the efficiency of nitrogen fixation by bolide impacts in CO2‐N2 atmospheres with or without H2. Surprisingly, nitricoxide(NO)wasproducedmoreefficientlyin20%H2 inspiteofbeingareducingagentandnotlikelyto increase the rate of nitrogen oxidation. Nevertheless, its presence led to a faster cooling of the shock wave raising the freeze‐out temperature of NO resulting in an enhanced yield. We estimate that the nitrogen fixation rate by bolide impacts varied from 7 × 10−4 to 2 × 10−3 g N·Myr−1·cm−2 and could imply fluvial concentration to explain the nitrogen (1.4 ± 0.7 g N·Myr−1·cm−2) detected as nitrite (NO2−) and nitrate (NO3−) by Curiosity at Yellowknife Bay. One possible explanation is that the nitrogen detected in the lacustrine sediments at Gale was deposited entirely on the crater's surface and was subsequently dissolved and transported by superficial and ground waters to the lake during favorable wet climatic conditions. The nitrogencontentsharplydecreasesinyoungersedimentsoftheMurrayformationsuggestingadeclineofH2 in the atmosphere and the rise of oxidizing conditions causing a shortage in the supply to putative microbial life.

Published
2019

5. Mars methane detection and variability at Gale crater

Author

Webster, Christopher R., Mahaffy, Paul R., Atreya, Sushil K., Flesch, Gregory J., Mischna, Michael A., Meslin, Pierre-Yves, Farley, Kenneth A., Conrad, Pamela G., Christensen, Lance E., Pavlov, Alexander A., Martin-Torres, Javier, Zorzano, Maria-Paz, McConnochie, Timothy H., Owen, Tobias, Eigenbrode, Jennifer L., Glavin, Daniel P., Steele, Andrew, Malespin, Charles A., Archer, P. Douglas, Jr., Sutter, Brad, Coll, Patrice, Freissinet, Caroline, McKay, Christopher P., Moores, John E., Schwenzer, Susanne P., Bridges, John C., Navarro-Gonzalez, Rafael, Gellert, Ralf, Lemmon, Mark T., Stipp, Susan Louise Svane, Webster, Christopher R., Mahaffy, Paul R., Atreya, Sushil K., Flesch, Gregory J., Mischna, Michael A., Meslin, Pierre-Yves, Farley, Kenneth A., Conrad, Pamela G., Christensen, Lance E., Pavlov, Alexander A., Martin-Torres, Javier, Zorzano, Maria-Paz, McConnochie, Timothy H., Owen, Tobias, Eigenbrode, Jennifer L., Glavin, Daniel P., Steele, Andrew, Malespin, Charles A., Archer, P. Douglas, Jr., Sutter, Brad, Coll, Patrice, Freissinet, Caroline, McKay, Christopher P., Moores, John E., Schwenzer, Susanne P., Bridges, John C., Navarro-Gonzalez, Rafael, Gellert, Ralf, Lemmon, Mark T., and Stipp, Susan Louise Svane

Published
2015

6. Transient liquid water and water activity at Gale crater on Mars

Author

Martin-Torres, F. Javier, Zorzano, Maria-Paz, Valentin-Serrano, Patricia, Harri, Ari-Matti, Genzer, Maria, Kemppinen, Osku, Rivera-Valentin, Edgard G., Jun, Insoo, Wray, James, Bo Madsen, Morten, Goetz, Walter, McEwen, Alfred S., Hardgrove, Craig, Renno, Nilton, Chevrier, Vincent F., Mischna, Michael, Navarro-Gonzalez, Rafael, Martinez-Frias, Jesus, Conrad, Pamela, McConnochie, Tim, Cockell, Charles, Berger, Gilles, Vasavada, Ashwin R., Sumner, Dawn, Vaniman, David, Martin-Torres, F. Javier, Zorzano, Maria-Paz, Valentin-Serrano, Patricia, Harri, Ari-Matti, Genzer, Maria, Kemppinen, Osku, Rivera-Valentin, Edgard G., Jun, Insoo, Wray, James, Bo Madsen, Morten, Goetz, Walter, McEwen, Alfred S., Hardgrove, Craig, Renno, Nilton, Chevrier, Vincent F., Mischna, Michael, Navarro-Gonzalez, Rafael, Martinez-Frias, Jesus, Conrad, Pamela, McConnochie, Tim, Cockell, Charles, Berger, Gilles, Vasavada, Ashwin R., Sumner, Dawn, and Vaniman, David

Published
2015

7. Possible detection of perchlorates by the Sample Analysis at Mars (SAM) Instrument : Comparison with previous missions

Author

Navarro-Gonzalez, Rafael, Sutter, Brad, Archer, Doug, Ming, Doug, Eigenbrode, Jennifer, Franz, Heather, Glavin, Daniel, McAdam, Amy, Stern, Jennifer, McKay, Christopher, Coll, Patrice, Cabane, Michel, Conrad, Pamela, Mahaffy, Paul, Martin-Torres, Javier, Zorzano-Mier, Maria, Grotzinger, John, Navarro-Gonzalez, Rafael, Sutter, Brad, Archer, Doug, Ming, Doug, Eigenbrode, Jennifer, Franz, Heather, Glavin, Daniel, McAdam, Amy, Stern, Jennifer, McKay, Christopher, Coll, Patrice, Cabane, Michel, Conrad, Pamela, Mahaffy, Paul, Martin-Torres, Javier, Zorzano-Mier, Maria, and Grotzinger, John

Abstract

Upprättat; 2013; 20150702 (ninhul)

Published
2013

8. Possible detection of perchlorates by the Sample Analysis at Mars (SAM) Instrument : Comparison with previous missions

Author

Navarro-Gonzalez, Rafael, Sutter, Brad, Archer, Doug, Ming, Doug, Eigenbrode, Jennifer, Franz, Heather, Glavin, Daniel, McAdam, Amy, Stern, Jennifer, McKay, Christopher, Coll, Patrice, Cabane, Michel, Conrad, Pamela, Mahaffy, Paul, Martin-Torres, Javier, Zorzano-Mier, Maria, Grotzinger, John, Navarro-Gonzalez, Rafael, Sutter, Brad, Archer, Doug, Ming, Doug, Eigenbrode, Jennifer, Franz, Heather, Glavin, Daniel, McAdam, Amy, Stern, Jennifer, McKay, Christopher, Coll, Patrice, Cabane, Michel, Conrad, Pamela, Mahaffy, Paul, Martin-Torres, Javier, Zorzano-Mier, Maria, and Grotzinger, John

Abstract

Upprättat; 2013; 20150702 (ninhul)

Published
2013

9. VERBAL AND NONVERBAL PROCESSING AMONG LEFT- AND RIGHT-HANDED GOOD READERS AND READING-DISABLED CHILDREN.

Author

CONRAD, PAMELA FANKHAUSER. and CONRAD, PAMELA FANKHAUSER.

Abstract

Differences in cerebral lateralization of verbal and nonverbal stimuli between left- and right-handed good readers and left- and right-handed reading-disabled children were examined. The study utilized the dichotic listening paradigm and examined the effects of directed attention on the processing of consonant-vowel (CV) and tonal stimuli by the four groups. The sixty subjects included fifteen right-handed good readers (eleven females and four males, mean age 10-3), fifteen left-handed good readers (eight females and seven males, mean age 10-5), fifteen right-handed reading-disabled children (six females and nine males, mean age 10-5), and fifteen left-handed reading-disabled children (four females and eleven males, mean age 10-8). All left-handed subjects had sinistral relatives. A three-factorial analysis of variance resulted in a significant left ear advantage (LEA) for tonal stimuli across all directed attention conditions for all groups. When presented with CV stimuli, the right-handed good readers produced a significant right ear advantage (REA) across all attentional conditions. The left-handed good readers and left-handed reading-disabled children were left ear (LE) dominant in the free recall and directed left conditions but produced a shift toward the right ear (RE) during the directed right condition. Right-handed reading-disabled children demonstrated a REA during free recall and directed right but were able to direct attention to the LE in the directed left condition. The study provided initial findings on the auditory processing of simple tonal stimuli among anomalous groups of children and documented the strong LEA found in previous studies of adult subjects. Verbal processing results for right-handed good readers and reading-disabled children confirmed previous findings with these populations. Reversed verbal processing (right hemisphere) was documented in both left-handed groups in two of the experimental conditions. The results provide additional s

Published
1987

10. Mars methane detection and variability at Gale crater

Author

Webster, Christopher R., Mahaffy, Paul R., Atreya, Sushil K., Flesh, Gregory J., Mishna, Michael A., Meslin, Pierre-Yves, Farley, Kenneth A., Conrad, Pamela G., Christensen, Lance E., Pavlov, Alexander A., Martin-Torres, Javier, Zorzano, María-Paz, McConnochie, Timothy H., Owen, Tobias, Eigenbrode, Jennifer L., Glavin, Daniel P., Steele, Andrew, Malespin, Charles A., Archer Jr., P. Douglas, Sutter, Brad, Coll, Patrice, Freissnet, Caroline, McKay, Christopher P., Mores, John L., Schwenzer, Susanne P., Bridges, John C., Navarro-Gonzalez, Rafael, Gellert, Ralf, Lemmon, Mark T., Webster, Christopher R., Mahaffy, Paul R., Atreya, Sushil K., Flesh, Gregory J., Mishna, Michael A., Meslin, Pierre-Yves, Farley, Kenneth A., Conrad, Pamela G., Christensen, Lance E., Pavlov, Alexander A., Martin-Torres, Javier, Zorzano, María-Paz, McConnochie, Timothy H., Owen, Tobias, Eigenbrode, Jennifer L., Glavin, Daniel P., Steele, Andrew, Malespin, Charles A., Archer Jr., P. Douglas, Sutter, Brad, Coll, Patrice, Freissnet, Caroline, McKay, Christopher P., Mores, John L., Schwenzer, Susanne P., Bridges, John C., Navarro-Gonzalez, Rafael, Gellert, Ralf, and Lemmon, Mark T.

Abstract

Reports of plumes or patches of methane in the martian atmosphere that vary over monthly time scales have defied explanation to date. From in situ measurements made over a 20-month period by the tunable laser spectrometer of the Sample Analysis at Mars instrument suite on Curiosity at Gale crater, we report detection of background levels of atmospheric methane of mean value 0.69 ± 0.25 parts per billion by volume (ppbv) at the 95% confidence interval (CI). This abundance is lower than model estimates of ultraviolet degradation of accreted interplanetary dust particles or carbonaceous chondrite material. Additionally, in four sequential measurements spanning a 60-sol period (where 1 sol is a martian day), we observed elevated levels of methane of 7.2 ± 2.1 ppbv (95% CI), implying that Mars is episodically producing methane from an additional unknown source.

11. Mars methane detection and variability at Gale crater

Author

Webster, Christopher R., Mahaffy, Paul R., Atreya, Sushil K., Flesh, Gregory J., Mishna, Michael A., Meslin, Pierre-Yves, Farley, Kenneth A., Conrad, Pamela G., Christensen, Lance E., Pavlov, Alexander A., Martin-Torres, Javier, Zorzano, María-Paz, McConnochie, Timothy H., Owen, Tobias, Eigenbrode, Jennifer L., Glavin, Daniel P., Steele, Andrew, Malespin, Charles A., Archer Jr., P. Douglas, Sutter, Brad, Coll, Patrice, Freissnet, Caroline, McKay, Christopher P., Mores, John L., Schwenzer, Susanne P., Bridges, John C., Navarro-Gonzalez, Rafael, Gellert, Ralf, Lemmon, Mark T., Webster, Christopher R., Mahaffy, Paul R., Atreya, Sushil K., Flesh, Gregory J., Mishna, Michael A., Meslin, Pierre-Yves, Farley, Kenneth A., Conrad, Pamela G., Christensen, Lance E., Pavlov, Alexander A., Martin-Torres, Javier, Zorzano, María-Paz, McConnochie, Timothy H., Owen, Tobias, Eigenbrode, Jennifer L., Glavin, Daniel P., Steele, Andrew, Malespin, Charles A., Archer Jr., P. Douglas, Sutter, Brad, Coll, Patrice, Freissnet, Caroline, McKay, Christopher P., Mores, John L., Schwenzer, Susanne P., Bridges, John C., Navarro-Gonzalez, Rafael, Gellert, Ralf, and Lemmon, Mark T.

Abstract

Reports of plumes or patches of methane in the martian atmosphere that vary over monthly time scales have defied explanation to date. From in situ measurements made over a 20-month period by the tunable laser spectrometer of the Sample Analysis at Mars instrument suite on Curiosity at Gale crater, we report detection of background levels of atmospheric methane of mean value 0.69 ± 0.25 parts per billion by volume (ppbv) at the 95% confidence interval (CI). This abundance is lower than model estimates of ultraviolet degradation of accreted interplanetary dust particles or carbonaceous chondrite material. Additionally, in four sequential measurements spanning a 60-sol period (where 1 sol is a martian day), we observed elevated levels of methane of 7.2 ± 2.1 ppbv (95% CI), implying that Mars is episodically producing methane from an additional unknown source.

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