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Dickson JL, Palumbo AM, Head JW, Kerber L, Fassett CI, Kreslavsky MA. Gullies on Mars could have formed by melting of water ice during periods of high obliquity. Science 2023; 380:1363-1367. [PMID: 37384686 DOI: 10.1126/science.abk2464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 05/19/2023] [Indexed: 07/01/2023]
Abstract
Gullies on Mars resemble water-carved channels on Earth, but they are mostly at elevations where liquid water is not expected under current climate conditions. It has been suggested that sublimation of carbon dioxide ice alone could have formed Martian gullies. We used a general circulation model to show that the highest-elevation Martian gullies coincide with the boundary of terrain that experienced pressures above the triple point of water when Mars' rotational axis tilt reached 35°. Those conditions have occurred repeatedly over the past several million years, most recently ~630,000 years ago. Surface water ice, if present at these locations, could have melted when temperatures rose >273 kelvin. We propose a dual gully formation scenario that is driven by melting of water ice followed by carbon dioxide ice sublimation.
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Affiliation(s)
- J L Dickson
- Division of Geological and Planetary Sciences, Caltech, Pasadena, CA, USA
- Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, USA
| | - A M Palumbo
- Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, USA
| | - J W Head
- Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, USA
| | - L Kerber
- Jet Propulsion Laboratory, Caltech, Pasadena, CA, USA
| | - C I Fassett
- NASA Marshall Space Flight Center, Huntsville, AL, USA
| | - M A Kreslavsky
- Earth and Planetary Sciences, University of California, Santa Cruz, CA, USA
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2
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Gary‐Bicas CE, Michaels TI, Rogers AD, Fenton LK, Warner NH, Cowart AC. Investigating the Role of Amazonian Mesoscale Wind Patterns and Strength on the Spatial Distribution of Martian Bedrock Exposures. JOURNAL OF GEOPHYSICAL RESEARCH. PLANETS 2022; 127:e2022JE007496. [PMID: 37035522 PMCID: PMC10078484 DOI: 10.1029/2022je007496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/06/2022] [Accepted: 11/06/2022] [Indexed: 06/19/2023]
Abstract
The Martian highlands contain Noachian-aged areally-extensive (>225 km2) bedrock exposures that have been mapped using thermal and visible imaging datasets. Given their age, crater density and impact gardening should have led to the formation of decameter scale layers of regolith that would overlie and bury these outcrops if composed of competent materials like basaltic lavas. However, many of these regions lack thick regolith layers and show clear exposures of bedrock materials with elevated thermal inertia values compared to the global average. Hypothesized reasons for the lack of regolith include: (a) relatively weaker material properties than lavas, where friable materials are comminuted and deflated during wind erosion, (b) long-term protection from regolith development through burial and later exhumation through one or more surface processes, and (c) spatially concentrated aeolian erosion and wind energetics on well-lithified basaltic substrates. To test the third hypothesis, we used the Mars Regional Atmospheric Modeling System to calculate wind erosive strength at 10 regions throughout the Martian highlands and compared it to their thermophysical properties by using thermal infrared data derived from the Thermal Emission Spectrometer to understand the effect that Amazonian mesoscale wind patterns may have on the exposure of bedrock. We also investigated the effect of planet obliquity, Ls of perihelion, and atmospheric mean pressure on wind erosion potential. We found no evidence for increased aeolian activity over bedrock-containing regions relative to surrounding terrains, including at the mafic floor unit at Jezero crater (Máaz formation), supporting the first or second hypotheses for these regions.
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Affiliation(s)
| | | | - A. D. Rogers
- Department of GeosciencesStony Brook UniversityStony BrookNYUSA
| | - L. K. Fenton
- Carl Sagan CenterSETI InstituteMountain ViewCAUSA
| | - N. H. Warner
- Department of Geological SciencesState University of New York at GeneseoGeneseoNYUSA
| | - A. C. Cowart
- Department of GeosciencesStony Brook UniversityStony BrookNYUSA
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3
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Abstract
Ground-based telescopes and space exploration have provided outstanding observations of the complexity of icy planetary surfaces. This work presents our review of the varying nature of carbon dioxide (CO2) and carbon monoxide (CO) ices from the cold traps on the Moon to Pluto in the Kuiper Belt. This review is organized into five parts. First, we review the mineral physics (e.g., rheology) relevant to these environments. Next, we review the radiation-induced chemical processes and the current interpretation of spectral signatures. The third section discusses the nature and distribution of CO2 in the giant planetary systems of Jupiter and Saturn, which are much better understood than the satellites of Uranus and Neptune, discussed in the subsequent section. The final sections focus on Pluto in comparison to Triton, having mainly CO, and a brief overview of cometary materials. We find that CO2 ices exist on many of these icy bodies by way of magnetospheric influence, while intermixing into solid ices with CH4 (methane) and N2 (nitrogen) out to Triton and Pluto. Such radiative mechanisms or intermixing can provide a wide diversity of icy surfaces, though we conclude where further experimental research of these ices is still needed.
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SHARAD Observations of Temporal Variations of CO2 Ice Deposits at the South Pole of Mars. REMOTE SENSING 2022. [DOI: 10.3390/rs14030435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mars’s polar regions are covered by kilometers-thick layered deposits which carry a record of the planet’s climate history. The deposition and volatilization of the shallow CO2 deposits in the south pole have a large impact on the planet’s atmosphere and environment. This research focuses on the timing variation of the thickness of the shallow deposits based on the SHARAD data collected from the past 11 terrestrial years, and analysis of the contributing factors based on the volatilization and deposition mechanisms of surface and subsurface materials. In this work, we selected more than four thousand data points, covering several seasons and Martian years, to extract radar echoes and calculate the thickness changes in the subsurface layer over time. We found that the thickness of the CO2 layer becomes thinner in the summer, with seasonal variation in the range of ~16–45 m. The thickness variations have a Gaussian-like distribution and do not increase with the distance between the compared node pair, implying that the phenomenon is not caused by regional differences. The overall thickness within the 11 terrestrial years does not show a clear trend of thickening or thinning, indicating a moderate vertical change of the southern deposits.
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Thomas N, Becerra P, Smith IB. Mars and the ESA Science Programme - the case for Mars polar science. EXPERIMENTAL ASTRONOMY 2021; 54:677-693. [PMID: 36915620 PMCID: PMC9998569 DOI: 10.1007/s10686-021-09760-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 05/07/2021] [Indexed: 06/18/2023]
Abstract
Current plans within the European Space Agency (ESA) for the future investigation of Mars (after the ExoMars programme) are centred around participation in the Mars Sample Return (MSR) programme led by NASA. This programme is housed within the Human and Robotic Exploration (HRE) Directorate of ESA. This White Paper, in response to the Voyage 2050 call, focuses on the important scientific objectives for the investigation of Mars outside the present HRE planning. The achievement of these objectives by Science Directorate missions is entirely consistent with ESA's Science Programme. We illustrate this with a theme centred around the study of the Martian polar caps and the investigation of recent (Amazonian) climate change produced by known oscillations in Mars' orbital parameters. Deciphering the record of climate contained within the polar caps would allow us to learn about the climatic evolution of another planet over the past few to hundreds of millions of years, and also addresses the more general goal of investigating volatile-related dynamic processes in the Solar System.
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Affiliation(s)
- Nicolas Thomas
- Physikalisches Institut, University of Bern, Sidlerstr. 5, CH-3012 Bern, Switzerland
| | - P. Becerra
- Physikalisches Institut, University of Bern, Sidlerstr. 5, CH-3012 Bern, Switzerland
| | - I. B. Smith
- Earth and Space Science and Engineering, Lassonde School of Engineering, York University, Toronto, Canada
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6
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Orosei R, Ding C, Fa W, Giannopoulos A, Hérique A, Kofman W, Lauro SE, Li C, Pettinelli E, Su Y, Xing S, Xu Y. The Global Search for Liquid Water on Mars from Orbit: Current and Future Perspectives. Life (Basel) 2020; 10:life10080120. [PMID: 32722008 PMCID: PMC7460233 DOI: 10.3390/life10080120] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/17/2020] [Accepted: 07/20/2020] [Indexed: 12/02/2022] Open
Abstract
Due to its significance in astrobiology, assessing the amount and state of liquid water present on Mars today has become one of the drivers of its exploration. Subglacial water was identified by the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) aboard the European Space Agency spacecraft Mars Express through the analysis of echoes, coming from a depth of about 1.5 km, which were stronger than surface echoes. The cause of this anomalous characteristic is the high relative permittivity of water-bearing materials, resulting in a high reflection coefficient. A determining factor in the occurrence of such strong echoes is the low attenuation of the MARSIS radar pulse in cold water ice, the main constituent of the Martian polar caps. The present analysis clarifies that the conditions causing exceptionally strong subsurface echoes occur solely in the Martian polar caps, and that the detection of subsurface water under a predominantly rocky surface layer using radar sounding will require thorough electromagnetic modeling, complicated by the lack of knowledge of many subsurface physical parameters. Higher-frequency radar sounders such as SHARAD cannot penetrate deep enough to detect basal echoes over the thickest part of the polar caps. Alternative methods such as rover-borne Ground Penetrating Radar and time-domain electromagnetic sounding are not capable of providing global coverage. MARSIS observations over the Martian polar caps have been limited by the need to downlink data before on-board processing, but their number will increase in coming years. The Chinese mission to Mars that is to be launched in 2020, Tianwen-1, will carry a subsurface sounding radar operating at frequencies that are close to those of MARSIS, and the expected signal-to-noise ratio of subsurface detection will likely be sufficient for identifying anomalously bright subsurface reflectors. The search for subsurface water through radar sounding is thus far from being concluded.
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Affiliation(s)
- Roberto Orosei
- Istituto di Radioastronomia, Istituto Nazionale di Astrofisica, Via Piero Gobetti 101, 40129 Bologna, Italy
- Correspondence:
| | - Chunyu Ding
- School of Atmosphere Sciences, Sun Yat-sen University, 2 Daxue Road, Xiangzhou District, Zhuhai City 519000, China;
| | - Wenzhe Fa
- Institute of Remote Sensing and Geographical Information System, School of Earth and Space Sciences, Peking University, Beijing 100871, China;
| | - Antonios Giannopoulos
- School of Engineering, The University of Edinburgh, Alexander Graham Bell Building, Thomas Bayes Road, Edinburgh EH9 3FG, UK;
| | - Alain Hérique
- Université Grenoble Alpes, CNRS, CNES, IPAG, 38000 Grenoble, France; (A.H.); (W.K.)
| | - Wlodek Kofman
- Université Grenoble Alpes, CNRS, CNES, IPAG, 38000 Grenoble, France; (A.H.); (W.K.)
- Centrum Badan Kosmicznych Polskiej Akademii Nauk (CBK PAN), Bartycka 18A, 00-716 Warsaw, Poland
| | - Sebastian E. Lauro
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy; (S.E.L.); (E.P.)
| | - Chunlai Li
- Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100101, China; (C.L.); (Y.S.)
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Elena Pettinelli
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy; (S.E.L.); (E.P.)
| | - Yan Su
- Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100101, China; (C.L.); (Y.S.)
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Shuguo Xing
- Piesat Information Technology Co., Ltd, Beijing 100195, China;
| | - Yi Xu
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau;
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7
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Liquid Water Detection under the South Polar Layered Deposits of Mars—a Probabilistic Inversion Approach. REMOTE SENSING 2019. [DOI: 10.3390/rs11202445] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Liquid water was present on the surface of Mars in the distant past; part of that water is now in the ground in the form of permafrost and heat from the molten interior of the planet could cause it to melt at depth. MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) has surveyed the Martian subsurface for more than fifteen years in search for evidence of such water buried at depth. Radar detection of liquid water can be stated as an inverse electromagnetic scattering problem, starting from the echo intensity collected by the antenna. In principle, the electromagnetic problem can be modelled as a normal plane wave that propagates through a three-layered medium made of air, ice and basal material, with the final goal of determining the dielectric permittivity of the basal material. In practice, however, two fundamental aspects make the inversion procedure of this apparent simple model rather challenging: i) the impossibility to use the absolute value of the echo intensity in the inversion procedure; ii) the impossibility to use a deterministic approach to retrieve the basal permittivity. In this paper, these issues are faced by assuming a priori information on the ice electromagnetic properties and adopting an inversion probabilistic approach. All the aspects that can affect the estimation of the basal permittivity below the Martian South polar cap are discussed and how detection of the presence of basal liquid water was done is described.
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8
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Habitability of Mars: How Welcoming Are the Surface and Subsurface to Life on the Red Planet? GEOSCIENCES 2019. [DOI: 10.3390/geosciences9090361] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mars is a planet of great interest in the search for signatures of past or present life beyond Earth. The years of research, and more advanced instrumentation, have yielded a lot of evidence which may be considered by the scientific community as proof of past or present habitability of Mars. Recent discoveries including seasonal methane releases and a subglacial lake are exciting, yet challenging findings. Concurrently, laboratory and environmental studies on the limits of microbial life in extreme environments on Earth broaden our knowledge of the possibility of Mars habitability. In this review, we aim to: (1) Discuss the characteristics of the Martian surface and subsurface that may be conducive to habitability either in the past or at present; (2) discuss laboratory-based studies on Earth that provide us with discoveries on the limits of life; and (3) summarize the current state of knowledge in terms of direction for future research.
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9
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Orosei R, Lauro SE, Pettinelli E, Cicchetti A, Coradini M, Cosciotti B, Di Paolo F, Flamini E, Mattei E, Pajola M, Soldovieri F, Cartacci M, Cassenti F, Frigeri A, Giuppi S, Martufi R, Masdea A, Mitri G, Nenna C, Noschese R, Restano M, Seu R. Radar evidence of subglacial liquid water on Mars. Science 2018; 361:490-493. [PMID: 30045881 DOI: 10.1126/science.aar7268] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 06/20/2018] [Indexed: 11/02/2022]
Abstract
The presence of liquid water at the base of the martian polar caps has long been suspected but not observed. We surveyed the Planum Australe region using the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) instrument, a low-frequency radar on the Mars Express spacecraft. Radar profiles collected between May 2012 and December 2015 contain evidence of liquid water trapped below the ice of the South Polar Layered Deposits. Anomalously bright subsurface reflections are evident within a well-defined, 20-kilometer-wide zone centered at 193°E, 81°S, which is surrounded by much less reflective areas. Quantitative analysis of the radar signals shows that this bright feature has high relative dielectric permittivity (>15), matching that of water-bearing materials. We interpret this feature as a stable body of liquid water on Mars.
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Affiliation(s)
- R Orosei
- Istituto di Radioastronomia, Istituto Nazionale di Astrofisica, Via Piero Gobetti 101, 40129 Bologna, Italy.
| | - S E Lauro
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
| | - E Pettinelli
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
| | - A Cicchetti
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica, Via del Fosso del Cavaliere 100, 00133 Roma, Italy
| | - M Coradini
- Agenzia Spaziale Italiana, Via del Politecnico, 00133 Roma, Italy
| | - B Cosciotti
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
| | - F Di Paolo
- Istituto di Radioastronomia, Istituto Nazionale di Astrofisica, Via Piero Gobetti 101, 40129 Bologna, Italy
| | - E Flamini
- Agenzia Spaziale Italiana, Via del Politecnico, 00133 Roma, Italy
| | - E Mattei
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica, Via del Fosso del Cavaliere 100, 00133 Roma, Italy
| | - M Pajola
- Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, Vicolo Osservatorio 5, 35122 Padova, Italy
| | - F Soldovieri
- Consiglio Nazionale delle Ricerche, Istituto per il Rilevamento Elettromagnetico dell'Ambiente, Via Diocleziano 328, 80124 Napoli, Italy
| | - M Cartacci
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica, Via del Fosso del Cavaliere 100, 00133 Roma, Italy
| | - F Cassenti
- Dipartimento di Ingegneria dell'Informazione, Elettronica e Telecomunicazioni, Università degli Studi di Roma "La Sapienza," Via Eudossiana 18, 00184 Roma, Italy
| | - A Frigeri
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica, Via del Fosso del Cavaliere 100, 00133 Roma, Italy
| | - S Giuppi
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica, Via del Fosso del Cavaliere 100, 00133 Roma, Italy
| | - R Martufi
- Dipartimento di Ingegneria dell'Informazione, Elettronica e Telecomunicazioni, Università degli Studi di Roma "La Sapienza," Via Eudossiana 18, 00184 Roma, Italy
| | - A Masdea
- E.P. Elettronica Progetti, Via Traspontina 25, 00040 Ariccia (RM), Italy
| | - G Mitri
- International Research School of Planetary Sciences, Università degli Studi "Gabriele d'Annunzio," Viale Pindaro 42, 65127 Pescara (PE), Italy
| | - C Nenna
- Danfoss Drives, Romstrasse 2 - Via Roma 2, 39014 Burgstall - Postal (BZ), Italy
| | - R Noschese
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica, Via del Fosso del Cavaliere 100, 00133 Roma, Italy
| | - M Restano
- Serco, c/o ESA Centre for Earth Observation, Largo Galileo Galilei 1, 00044 Frascati (RM), Italy
| | - R Seu
- Dipartimento di Ingegneria dell'Informazione, Elettronica e Telecomunicazioni, Università degli Studi di Roma "La Sapienza," Via Eudossiana 18, 00184 Roma, Italy
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10
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Putzig NE, Smith IB, Perry MR, Foss FJ, Campbell BA, Phillips RJ, Seu R. Three-dimensional radar imaging of structures and craters in the Martian polar caps. ICARUS 2018; 308:138-147. [PMID: 29749975 PMCID: PMC5937288 DOI: 10.1016/j.icarus.2017.09.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Over the last decade, observations acquired by the Shallow Radar (SHARAD) sounder on individual passes of the Mars Reconnaissance Orbiter have revealed the internal structure of the Martian polar caps and provided new insights into the formation of the icy layers within and their relationship to climate. However, a complete picture of the cap interiors has been hampered by interfering reflections from off-nadir surface features and signal losses associated with sloping structures and scattering. Foss et al. (2017) addressed these limitations by assembling three-dimensional data volumes of SHARAD observations from thousands of orbital passes over each polar region and applying geometric corrections simultaneously. The radar volumes provide unprecedented views of subsurface features, readily imaging structures previously inferred from time-intensive manual analysis of single-orbit data (e.g., trough-bounding surfaces, a buried chasma, and a basal unit in the north, massive carbon-dioxide ice deposits and discontinuous layered sequences in the south). Our new mapping of the carbon-dioxide deposits yields a volume of 16,500 km3, 11% larger than the prior estimate. In addition, the radar volumes newly reveal other structures, including what appear to be buried impact craters with no surface expression. Our first assessment of 21 apparent craters at the base of the north polar layered deposits suggests a Hesperian age for the substrate, consistent with that of the surrounding plains as determined from statistics of surface cratering rates. Planned mapping of similar features throughout both polar volumes may provide new constraints on the age of the icy layered deposits. The radar volumes also provide new topographic data between the highest latitudes observed by the Mars Orbiter Laser Altimeter and those observed by SHARAD. In general, mapping of features in these radar volumes is placing new constraints on the nature and evolution of the polar deposits and associated climate changes.
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Affiliation(s)
- Nathaniel E Putzig
- Planetary Science Institute, 1546 Cole Boulevard, Suite 120, Lakewood, CO 80401, USA
| | - Isaac B Smith
- Planetary Science Institute, 1546 Cole Boulevard, Suite 120, Lakewood, CO 80401, USA
| | - Matthew R Perry
- Planetary Science Institute, 1546 Cole Boulevard, Suite 120, Lakewood, CO 80401, USA
| | - Frederick J Foss
- Freestyle Analytical and Quantitative Services, LLC, 2210 Parkview Drive, Longmont, CO 80504, USA
| | - Bruce A Campbell
- Smithsonian Institution, MRC 315, Center for Earth and Planetary Studies, National Air and Space Museum, 4th and Independence Ave, SW, Washington, DC 20560, USA
| | - Roger J Phillips
- Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University in St. Louis, MO 63130, USA
| | - Roberto Seu
- Sapienza University of Rome, DIET Department, Via Eudossiana, 18, 00184 Rome, ITALY
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11
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Foss FJ, Putzig NE, Campbell BA, Phillips RJ. 3-D Imaging of Mars' Polar Ice Caps Using Orbital Radar Data. ACTA ACUST UNITED AC 2018; 36:43-57. [PMID: 29400351 DOI: 10.1190/tle36010043.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Since its arrival in early 2006, various instruments aboard NASA's Mars Reconnaissance Orbiter (MRO) have been collecting a variety of scientific and engineering data from orbit around Mars. Among these is the SHAllow RADar (SHARAD) instrument, supplied by Agenzia Spaziale Italiana (ASI) and designed for subsurface sounding in the 15-25 MHz frequency band. As of this writing, MRO has completed over 46,000 nearly polar orbits of Mars, 30% of which have included active SHARAD data collection. By 2009, a sufficient density of SHARAD coverage had been obtained over the polar regions to support 3-D processing and analysis of the data. Using tools and techniques commonly employed in terrestrial seismic data processing, we have processed subsets of the resulting collection of SHARAD observations covering the north and south polar regions as SHARAD 3-D volumes, imaging the interiors of the north and south polar ice caps known, respectively, as Planum Boreum and Planum Australe. After overcoming a series of challenges revealed during the 3-D processing and analysis, a completed Planum Boreum 3-D volume is currently being used for scientific research. Lessons learned in the northern work fed forward into our 3-D processing and analysis of the Planum Australe 3-D volume, currently under way. We discuss our experiences with these projects and present results and scientific insights stemming from these efforts.
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Affiliation(s)
- Frederick J Foss
- Freestyle Analytical & Quantitative Services, LLC, 2210 Parkview Drive, Longmont, CO 80504
| | - Nathaniel E Putzig
- Planetary Science Institute, 1546 Cole Blvd, Suite 120, Lakewood, CO 80401
| | - Bruce A Campbell
- Smithsonian Institution, MRC 315, PO Box 37012, Washington, DC 20013-7012
| | - Roger J Phillips
- Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University in St. Louis, Campus Box 1169, One Brookings Drive, St. Louis, MO 63130-4899
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12
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Jakosky BM, Slipski M, Benna M, Mahaffy P, Elrod M, Yelle R, Stone S, Alsaeed N. Mars' atmospheric history derived from upper-atmosphere measurements of 38Ar/ 36Ar. Science 2017; 355:1408-1410. [PMID: 28360326 DOI: 10.1126/science.aai7721] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 03/06/2017] [Indexed: 11/02/2022]
Abstract
The history of Mars' atmosphere is important for understanding the geological evolution and potential habitability of the planet. We determine the amount of gas lost to space through time using measurements of the upper-atmospheric structure made by the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft. We derive the structure of 38Ar/36Ar between the homopause and exobase altitudes. Fractionation of argon occurs as a result of loss of gas to space by pickup-ion sputtering, which preferentially removes the lighter atom. The measurements require that 66% of the atmospheric argon has been lost to space. Thus, a large fraction of Mars' atmospheric gas has been lost to space, contributing to the transition in climate from an early, warm, wet environment to today's cold, dry atmosphere.
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Affiliation(s)
| | - M Slipski
- University of Colorado, Boulder, CO, USA
| | - M Benna
- NASA/Goddard Spaceflight Center, Greenbelt, MD, USA
| | - P Mahaffy
- NASA/Goddard Spaceflight Center, Greenbelt, MD, USA
| | - M Elrod
- NASA/Goddard Spaceflight Center, Greenbelt, MD, USA
| | - R Yelle
- University of Arizona, Tucson, AZ, USA
| | - S Stone
- University of Arizona, Tucson, AZ, USA
| | - N Alsaeed
- University of Colorado, Boulder, CO, USA.,American University of Sharjah, Sharjah, United Arab Emirates
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13
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Read PL, Lewis SR, Mulholland DP. The physics of Martian weather and climate: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2015; 78:125901. [PMID: 26534887 DOI: 10.1088/0034-4885/78/12/125901] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The planet Mars hosts an atmosphere that is perhaps the closest in terms of its meteorology and climate to that of the Earth. But Mars differs from Earth in its greater distance from the Sun, its smaller size, its lack of liquid oceans and its thinner atmosphere, composed mainly of CO(2). These factors give Mars a rather different climate to that of the Earth. In this article we review various aspects of the martian climate system from a physicist's viewpoint, focusing on the processes that control the martian environment and comparing these with corresponding processes on Earth. These include the radiative and thermodynamical processes that determine the surface temperature and vertical structure of the atmosphere, the fluid dynamics of its atmospheric motions, and the key cycles of mineral dust and volatile transport. In many ways, the climate of Mars is as complicated and diverse as that of the Earth, with complex nonlinear feedbacks that affect its response to variations in external forcing. Recent work has shown that the martian climate is anything but static, but is almost certainly in a continual state of transient response to slowly varying insolation associated with cyclic variations in its orbit and rotation. We conclude with a discussion of the physical processes underlying these long- term climate variations on Mars, and an overview of some of the most intriguing outstanding problems that should be a focus for future observational and theoretical studies.
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Affiliation(s)
- P L Read
- Atmospheric, Oceanic & Planetary Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
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14
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Hu R, Kass DM, Ehlmann BL, Yung YL. Tracing the fate of carbon and the atmospheric evolution of Mars. Nat Commun 2015; 6:10003. [PMID: 26600077 PMCID: PMC4673500 DOI: 10.1038/ncomms10003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/26/2015] [Indexed: 11/18/2022] Open
Abstract
The climate of Mars likely evolved from a warmer, wetter early state to the cold, arid current state. However, no solutions for this evolution have previously been found to satisfy the observed geological features and isotopic measurements of the atmosphere. Here we show that a family of solutions exist, invoking no missing reservoirs or loss processes. Escape of carbon via CO photodissociation and sputtering enriches heavy carbon (13C) in the Martian atmosphere, partially compensated by moderate carbonate precipitation. The current atmospheric 13C/12C and rock and soil carbonate measurements indicate an early atmosphere with a surface pressure <1 bar. Only scenarios with large amounts of carbonate formation in open lakes permit higher values up to 1.8 bar. The evolutionary scenarios are fully testable with data from the MAVEN mission and further studies of the isotopic composition of carbonate in the Martian rock record through time. Mars likely evolved from a warmer, wetter early state to the cold, arid current climate, but this evolution is not reflected in recent observations and measurements. Here, the authors derive quantitative constraints on the atmospheric pressure through time, identifying a mechanism that explains the carbon data.
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Affiliation(s)
- Renyu Hu
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
| | - David M Kass
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
| | - Bethany L Ehlmann
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
| | - Yuk L Yung
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
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15
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Kofman W, Herique A, Barbin Y, Barriot JP, Ciarletti V, Clifford S, Edenhofer P, Elachi C, Eyraud C, Goutail JP, Heggy E, Jorda L, Lasue J, Levasseur-Regourd AC, Nielsen E, Pasquero P, Preusker F, Puget P, Plettemeier D, Rogez Y, Sierks H, Statz C, Svedhem H, Williams I, Zine S, Van Zyl J. COMETARY SCIENCE. Properties of the 67P/Churyumov-Gerasimenko interior revealed by CONSERT radar. Science 2015; 349:aab0639. [PMID: 26228153 DOI: 10.1126/science.aab0639] [Citation(s) in RCA: 159] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Philae lander provides a unique opportunity to investigate the internal structure of a comet nucleus, providing information about its formation and evolution in the early solar system. We present Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) measurements of the interior of Comet 67P/Churyumov-Gerasimenko. From the propagation time and form of the signals, the upper part of the "head" of 67P is fairly homogeneous on a spatial scale of tens of meters. CONSERT also reduced the size of the uncertainty of Philae's final landing site down to approximately 21 by 34 square meters. The average permittivity is about 1.27, suggesting that this region has a volumetric dust/ice ratio of 0.4 to 2.6 and a porosity of 75 to 85%. The dust component may be comparable to that of carbonaceous chondrites.
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Affiliation(s)
- Wlodek Kofman
- Université Grenoble Alpes, IPAG, F-38000 Grenoble, France (2) Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), F-38000 Grenoble, France
| | - Alain Herique
- Université Grenoble Alpes, IPAG, F-38000 Grenoble, France (2) Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), F-38000 Grenoble, France
| | - Yves Barbin
- MIO, UM 110, CNRS-Institut National des Sciences de l'Univers (INSU), Université de Toulon, Aix-Marseille Université, IRD 83957 La Garde, France
| | | | - Valérie Ciarletti
- Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) (UPSay); Université Pierre et Marie Curie (UPMC) (Sorbonne Univ.); CNRS/INSU; Laboratoire Atmosphéres, Milieux, Observations Spatiales (LATMOS)-Institut Pierre-Simon Laplace (IPSL), 11 Boulevard d'Alembert, 78280 Guyancourt, France
| | - Stephen Clifford
- Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, TX 77058, USA
| | - Peter Edenhofer
- Ruhr-University of Bochum, Faculty of Electrical Engineering and Information Technology, 44780 Bochum, Germany
| | - Charles Elachi
- Jet Propulsion Laboratory, 4800 Oak Grove Drive, MS 300-243E, Pasadena, CA 91109, USA
| | - Christelle Eyraud
- Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel UMR 7249, 13013 Marseille, France
| | - Jean-Pierre Goutail
- Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) (UPSay); Université Pierre et Marie Curie (UPMC) (Sorbonne Univ.); CNRS/INSU; Laboratoire Atmosphéres, Milieux, Observations Spatiales (LATMOS)-Institut Pierre-Simon Laplace (IPSL), 11 Boulevard d'Alembert, 78280 Guyancourt, France
| | - Essam Heggy
- Jet Propulsion Laboratory, 4800 Oak Grove Drive, MS 300-243E, Pasadena, CA 91109, USA. University of Southern California, Ming Hsieh Department of Electrical Engineering, Viterbi School of Engineering, Los Angeles, CA 90089, USA
| | - Laurent Jorda
- Laboratoire d'Astrophysique de Marseille Pôle de l'Étoile Site de Château-Gombert 38, Rue Frédéric Joliot-Curie 13388 Marseille, France
| | - Jérémie Lasue
- Université de Toulouse; UPS-OMP; IRAP; (2) CNRS; IRAP; 9 Avenue Colonel Roche, BP 44 346, F-31028 Toulouse Cedex 4, Toulouse, France
| | | | - Erling Nielsen
- Max-Planck-Institüt fur Sonnensystemforschung (MPS), Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | - Pierre Pasquero
- Université Grenoble Alpes, IPAG, F-38000 Grenoble, France (2) Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), F-38000 Grenoble, France
| | - Frank Preusker
- German Aerospace Center (DLR) Rutherfordstraße 2 12489 Berlin, Germany
| | - Pascal Puget
- Université Grenoble Alpes, IPAG, F-38000 Grenoble, France (2) Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), F-38000 Grenoble, France
| | - Dirk Plettemeier
- Technische Universitaet Dresden Helmholtzstraße 10 D-01069 Dresden, Germany
| | - Yves Rogez
- Université Grenoble Alpes, IPAG, F-38000 Grenoble, France (2) Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), F-38000 Grenoble, France
| | - Holger Sierks
- Max-Planck-Institüt fur Sonnensystemforschung (MPS), Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | - Christoph Statz
- Technische Universitaet Dresden Helmholtzstraße 10 D-01069 Dresden, Germany
| | - Hakan Svedhem
- European Space Agency (ESA)/European Space Research and Technology Centre (ESTEC) Noordwijk, Netherlands
| | - Iwan Williams
- Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Sonia Zine
- Université Grenoble Alpes, IPAG, F-38000 Grenoble, France (2) Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), F-38000 Grenoble, France
| | - Jakob Van Zyl
- Jet Propulsion Laboratory, 4800 Oak Grove Drive, MS 300-243E, Pasadena, CA 91109, USA
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Blake DF, Morris RV, Kocurek G, Morrison SM, Downs RT, Bish D, Ming DW, Edgett KS, Rubin D, Goetz W, Madsen MB, Sullivan R, Gellert R, Campbell I, Treiman AH, McLennan SM, Yen AS, Grotzinger J, Vaniman DT, Chipera SJ, Achilles CN, Rampe EB, Sumner D, Meslin PY, Maurice S, Forni O, Gasnault O, Fisk M, Schmidt M, Mahaffy P, Leshin LA, Glavin D, Steele A, Freissinet C, Navarro-González R, Yingst RA, Kah LC, Bridges N, Lewis KW, Bristow TF, Farmer JD, Crisp JA, Stolper EM, Des Marais DJ, Sarrazin P. Curiosity at Gale crater, Mars: characterization and analysis of the Rocknest sand shadow. Science 2013; 341:1239505. [PMID: 24072928 DOI: 10.1126/science.1239505] [Citation(s) in RCA: 231] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand <150 micrometers in size contains ~55% crystalline material consistent with a basaltic heritage and ~45% x-ray amorphous material. The amorphous component of Rocknest is iron-rich and silicon-poor and is the host of the volatiles (water, oxygen, sulfur dioxide, carbon dioxide, and chlorine) detected by the Sample Analysis at Mars instrument and of the fine-grained nanophase oxide component first described from basaltic soils analyzed by MERs. The similarity between soils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basaltic materials or globally and regionally sourced basaltic components deposited locally at all three locations.
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Affiliation(s)
- D F Blake
- National Aeronautics and Space Administration Ames Research Center, Moffett Field, CA 94035, USA.
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Brown AJ, Calvin WM, Murchie SL. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) north polar springtime recession mapping: First 3 Mars years of observations. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012je004113] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lee MW, Plattner N, Meuwly M. Structure, spectroscopy and dynamics of layered H2O and CO2 ices. Phys Chem Chem Phys 2012; 14:15464-74. [PMID: 23072896 DOI: 10.1039/c2cp41904a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Myung Won Lee
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
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Abstract
Clay minerals, recently discovered to be widespread in Mars's Noachian terrains, indicate long-duration interaction between water and rock over 3.7 billion years ago. Analysis of how they formed should indicate what environmental conditions prevailed on early Mars. If clays formed near the surface by weathering, as is common on Earth, their presence would indicate past surface conditions warmer and wetter than at present. However, available data instead indicate substantial Martian clay formation by hydrothermal groundwater circulation and a Noachian rock record dominated by evidence of subsurface waters. Cold, arid conditions with only transient surface water may have characterized Mars's surface for over 4 billion years, since the early-Noachian period, and the longest-duration aqueous, potentially habitable environments may have been in the subsurface.
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Affiliation(s)
- Peter C Thomas
- Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853, USA.
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