Kenneth Edward Herkenhoff, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 145
An atlas of Mars sedimentary rocks as seen by HiRISE
Images of distant and unknown places have long stimulated the imaginations of both explorers and scientists. The atlas of photographs collected during the Hayden (1872)expedition to the Yellowstone region was essential to its successful advocacy and selection in 1872 as America’s first national park. Photographer William Henry Jackson of the Hayden expedition captured the public’s imagination and
Authors
Ross Beyer, Kathryn M. Stack, Jennifer L. Griffes, Ralph E. Milliken, Kenneth E. Herkenhoff, Shane Byrne, John W. Holt, John P. Grotzinger
Ancient impact and aqueous processes at Endeavour Crater, Mars
The rover Opportunity has investigated the rim of Endeavour Crater, a large ancient impact crater on Mars. Basaltic breccias produced by the impact form the rim deposits, with stratigraphy similar to that observed at similar-sized craters on Earth. Highly localized zinc enrichments in some breccia materials suggest hydrothermal alteration of rim deposits. Gypsum-rich veins cut sedimentary rocks ad
Authors
S. W. Squyres, R. E. Arvidson, J.F. Bell, F.J. Calef, B. C. Clark, B. A. Cohen, L.A. Crumpler, P. A. de Souza, W. H. Farrand, Ralf Gellert, J. Grant, Kenneth E. Herkenhoff, J.A. Hurowitz, J. R. Johnson, B.L. Jolliff, A.H. Knoll, R. Li, S. M. McLennan, D. W. Ming, D. W. Mittlefehldt, T. J. Parker, G. Paulsen, M.S. Rice, S. W. Ruff, C. Schröder, A. S. Yen, K. Zacny
Temporal observations of bright soil exposures at Gusev crater, Mars
The Mars Exploration Rover Spirit has discovered bright soil deposits in its wheel tracks that previously have been confirmed to contain ferric sulfates and/or opaline silica. Repeated Pancam multispectral observations have been acquired at four of these deposits to monitor spectral and textural changes over time during exposure to Martian surface conditions. Previous studies suggested that tempor
Authors
M.S. Rice, J.F. Bell, E.A. Cloutis, J.J. Wray, Kenneth E. Herkenhoff, R. Sullivan, J. R. Johnson, R.B. Anderson
Characteristics, distribution, origin, and significance of opaline silica observed by the Spirit rover in Gusev crater, Mars
The presence of outcrops and soil (regolith) rich in opaline silica (∼65–92 wt % SiO2) in association with volcanic materials adjacent to the “Home Plate” feature in Gusev crater is evidence for hydrothermal conditions. The Spirit rover has supplied a diverse set of observations that are used here to better understand the formation of silica and the activity, abundance, and fate of water in the fi
Authors
S. W. Ruff, J.D. Farmer, W. M. Calvin, Kenneth E. Herkenhoff, J. R. Johnson, R.V. Morris, M.S. Rice, R. E. Arvidson, J.F. Bell, P. R. Christensen, S. W. Squyres
Spectral heterogeneity on Phobos and Deimos: HiRISE observations and comparisons to Mars Pathfinder results
The High-Resolution Imaging Science Experiment (HiRISE) onboard Mars Reconnaissance Orbiter (MRO) has been used to observe Phobos and Deimos at spatial scales of around 6 and 20 m/px, respectively. HiRISE (McEwen et al.; JGR, 112, CiteID E05S02, DOI: 10.1029/2005JE002605, 2007) has provided, for the first time, high-resolution colour images of the surfaces of the Martian moons. When processed, by
Authors
N. Thomas, R. Stelter, A. Ivanov, N.T. Bridges, Kenneth E. Herkenhoff, A. S. McEwen
Seasonal erosion and restoration of Mars' northern polar dunes
Despite radically different environmental conditions, terrestrial and martian dunes bear a strong resemblance, indicating that the basic processes of saltation and grainfall (sand avalanching down the dune slipface) operate on both worlds. Here, we show that martian dunes are subject to an additional modification process not found on Earth: springtime sublimation of Mars' CO 2 seasonal polar caps.
Authors
C.J. Hansen, M. Bourke, Nathan T. Bridges, Shane Byrne, C. Colon, S. Diniega, Colin M. Dundas, Kenneth E. Herkenhoff, A. McEwen, M. Mellon, Ganna Portyankina, N. Thomas
Opportunity Mars Rover mission: Overview and selected results from Purgatory ripple to traverses to Endeavour crater
Opportunity has been traversing the Meridiani plains since 25 January 2004 (sol 1), acquiring numerous observations of the atmosphere, soils, and rocks. This paper provides an overview of key discoveries between sols 511 and 2300, complementing earlier papers covering results from the initial phases of the mission. Key new results include (1) atmospheric argon measurements that demonstrate the imp
Authors
R. E. Arvidson, James W. Ashley, J.F. Bell, M. Chojnacki, J. Cohen, T.E. Economou, W. H. Farrand, Robin L. Fergason, I. Fleischer, Paul E. Geissler, Ralf Gellert, M.P. Golombek, J.P. Grotzinger, E.A. Guinness, R.M. Haberle, Kenneth E. Herkenhoff, J.A. Herman, K.D. Iagnemma, B.L. Jolliff, J. R. Johnson, G. Klingelhofer, A.H. Knoll, A.T. Knudson, R. Li, S. M. McLennan, D. W. Mittlefehldt, R.V. Morris, T. J. Parker, M.S. Rice, C. Schroder, Laurence A. Soderblom, S. W. Squyres, R.J. Sullivan, M.J. Wolff
Evidence for mechanical and chemical alteration of iron-nickel meteorites on Mars: Process insights for Meridiani Planum
The weathering of meteorites found on Mars involves chemical and physical processes that can provide clues to climate conditions at the location of their discovery. Beginning on sol 1961, the Opportunity rover encountered three large iron meteorites within a few hundred meters of each other. In order of discovery, these rocks have been assigned the unofficial names Block Island, Shelter Island, an
Authors
James W. Ashley, M.P. Golombek, P. R. Christensen, S. W. Squyres, T.J. McCoy, C. Schroder, I. Fleischer, J. R. Johnson, Kenneth E. Herkenhoff, T. J. Parker
Meteorites at Meridiani Planum provide evidence for significant amounts of surface and near-surface water on early Mars
Six large iron meteorites have been discovered in the Meridiani Planum region of Mars by the Mars Exploration Rover Opportunity in a nearly 25 km-long traverse. Herein, we review and synthesize the available data to propose that the discovery and characteristics of the six meteorites could be explained as the result of their impact into a soft and wet surface, sometime during the Noachian or the H
Authors
Alberto G. Fairen, James M. Dohm, Victor R. Baker, Shane D. Thompson, William C. Mahaney, Kenneth E. Herkenhoff, J. Alexis P. Rodriguez, Alfonso F. Davila, Dirk Schulze-Makuch, M. Ramy El Maarry, Esther R. Uceda, Ricardo Amils, Hirdy Miyamoto, Kyeong J. Kim, Robert C. Anderson, Christopher P. McKay
Crater population and resurfacing of the Martian north polar layered deposits
Present‐day accumulation in the north polar layered deposits (NPLD) is thought to occur via deposition on the north polar residual cap. Understanding current mass balance in relation to current climate would provide insight into the climatic record of the NPLD. To constrain processes and rates of NPLD resurfacing, a search for craters was conducted using images from the Mars Reconnaissance Orbiter
Authors
Maria E. Banks, Shane Byrne, Kapil Galla, Alfred S. McEwen, Veronica J. Bray, Colin M. Dundas, Kathryn E. Fishbaugh, Kenneth E. Herkenhoff, Bruce C. Murray
Visible and near-infrared multispectral analysis of geochemically measured rock fragments at the Opportunity landing site in Meridiani Planum
We have used visible and near‐infrared Panoramic Camera (Pancam) spectral data acquired by the Opportunity rover to analyze 15 rock fragments at the Meridiani Planum landing site. These spectral results were then compared to geochemistry measurements made by the in situ instruments Mössbauer (MB) and Alpha Particle X‐ray Spectrometer (APXS) to determine the feasibility of mineralogic characterizat
Authors
Catherine M. Weitz, William H. Farrand, Jeffrey R. Johnson, Iris Fleischer, Christian Schröder, Aileen Yingst, Bradley L. Jolliff, Ralf Gellert, Jim Bell, Kenneth E. Herkenhoff, G. Klingelhoefer, Barbara Cohen, Wendy M. Calvin, Malcolm Rutherford, James W. Ashley
Properties and distribution of paired candidate stony meteorites at Meridiani Planum
The Mars Exploration Rover Opportunity investigated four rocks, informally dubbed Barberton, Santa Catarina, Santorini, and Kasos, that are possible stony meteorites. Their chemical and mineralogical composition is similar to the howardite, eucrite, and diogenite group but with additional metal, similar to mesosiderite silicate clasts. Because of their virtually identical composition and because t
Authors
Christian Schröder, Kenneth E. Herkenhoff, William H. Farrand, John E. Chappelow, Wei Wang, L.R. Nittler, James W. Ashley, Iris Fleischer, Ralf Gellert, Matthew P. Golombek, Jeffrey R. Johnson, G. Klingelhoefer, Ron Li, Richard V. Morris, Steven W. Squyres
Science and Products
Filter Total Items: 145
An atlas of Mars sedimentary rocks as seen by HiRISE
Images of distant and unknown places have long stimulated the imaginations of both explorers and scientists. The atlas of photographs collected during the Hayden (1872)expedition to the Yellowstone region was essential to its successful advocacy and selection in 1872 as America’s first national park. Photographer William Henry Jackson of the Hayden expedition captured the public’s imagination and
Authors
Ross Beyer, Kathryn M. Stack, Jennifer L. Griffes, Ralph E. Milliken, Kenneth E. Herkenhoff, Shane Byrne, John W. Holt, John P. Grotzinger
Ancient impact and aqueous processes at Endeavour Crater, Mars
The rover Opportunity has investigated the rim of Endeavour Crater, a large ancient impact crater on Mars. Basaltic breccias produced by the impact form the rim deposits, with stratigraphy similar to that observed at similar-sized craters on Earth. Highly localized zinc enrichments in some breccia materials suggest hydrothermal alteration of rim deposits. Gypsum-rich veins cut sedimentary rocks ad
Authors
S. W. Squyres, R. E. Arvidson, J.F. Bell, F.J. Calef, B. C. Clark, B. A. Cohen, L.A. Crumpler, P. A. de Souza, W. H. Farrand, Ralf Gellert, J. Grant, Kenneth E. Herkenhoff, J.A. Hurowitz, J. R. Johnson, B.L. Jolliff, A.H. Knoll, R. Li, S. M. McLennan, D. W. Ming, D. W. Mittlefehldt, T. J. Parker, G. Paulsen, M.S. Rice, S. W. Ruff, C. Schröder, A. S. Yen, K. Zacny
Temporal observations of bright soil exposures at Gusev crater, Mars
The Mars Exploration Rover Spirit has discovered bright soil deposits in its wheel tracks that previously have been confirmed to contain ferric sulfates and/or opaline silica. Repeated Pancam multispectral observations have been acquired at four of these deposits to monitor spectral and textural changes over time during exposure to Martian surface conditions. Previous studies suggested that tempor
Authors
M.S. Rice, J.F. Bell, E.A. Cloutis, J.J. Wray, Kenneth E. Herkenhoff, R. Sullivan, J. R. Johnson, R.B. Anderson
Characteristics, distribution, origin, and significance of opaline silica observed by the Spirit rover in Gusev crater, Mars
The presence of outcrops and soil (regolith) rich in opaline silica (∼65–92 wt % SiO2) in association with volcanic materials adjacent to the “Home Plate” feature in Gusev crater is evidence for hydrothermal conditions. The Spirit rover has supplied a diverse set of observations that are used here to better understand the formation of silica and the activity, abundance, and fate of water in the fi
Authors
S. W. Ruff, J.D. Farmer, W. M. Calvin, Kenneth E. Herkenhoff, J. R. Johnson, R.V. Morris, M.S. Rice, R. E. Arvidson, J.F. Bell, P. R. Christensen, S. W. Squyres
Spectral heterogeneity on Phobos and Deimos: HiRISE observations and comparisons to Mars Pathfinder results
The High-Resolution Imaging Science Experiment (HiRISE) onboard Mars Reconnaissance Orbiter (MRO) has been used to observe Phobos and Deimos at spatial scales of around 6 and 20 m/px, respectively. HiRISE (McEwen et al.; JGR, 112, CiteID E05S02, DOI: 10.1029/2005JE002605, 2007) has provided, for the first time, high-resolution colour images of the surfaces of the Martian moons. When processed, by
Authors
N. Thomas, R. Stelter, A. Ivanov, N.T. Bridges, Kenneth E. Herkenhoff, A. S. McEwen
Seasonal erosion and restoration of Mars' northern polar dunes
Despite radically different environmental conditions, terrestrial and martian dunes bear a strong resemblance, indicating that the basic processes of saltation and grainfall (sand avalanching down the dune slipface) operate on both worlds. Here, we show that martian dunes are subject to an additional modification process not found on Earth: springtime sublimation of Mars' CO 2 seasonal polar caps.
Authors
C.J. Hansen, M. Bourke, Nathan T. Bridges, Shane Byrne, C. Colon, S. Diniega, Colin M. Dundas, Kenneth E. Herkenhoff, A. McEwen, M. Mellon, Ganna Portyankina, N. Thomas
Opportunity Mars Rover mission: Overview and selected results from Purgatory ripple to traverses to Endeavour crater
Opportunity has been traversing the Meridiani plains since 25 January 2004 (sol 1), acquiring numerous observations of the atmosphere, soils, and rocks. This paper provides an overview of key discoveries between sols 511 and 2300, complementing earlier papers covering results from the initial phases of the mission. Key new results include (1) atmospheric argon measurements that demonstrate the imp
Authors
R. E. Arvidson, James W. Ashley, J.F. Bell, M. Chojnacki, J. Cohen, T.E. Economou, W. H. Farrand, Robin L. Fergason, I. Fleischer, Paul E. Geissler, Ralf Gellert, M.P. Golombek, J.P. Grotzinger, E.A. Guinness, R.M. Haberle, Kenneth E. Herkenhoff, J.A. Herman, K.D. Iagnemma, B.L. Jolliff, J. R. Johnson, G. Klingelhofer, A.H. Knoll, A.T. Knudson, R. Li, S. M. McLennan, D. W. Mittlefehldt, R.V. Morris, T. J. Parker, M.S. Rice, C. Schroder, Laurence A. Soderblom, S. W. Squyres, R.J. Sullivan, M.J. Wolff
Evidence for mechanical and chemical alteration of iron-nickel meteorites on Mars: Process insights for Meridiani Planum
The weathering of meteorites found on Mars involves chemical and physical processes that can provide clues to climate conditions at the location of their discovery. Beginning on sol 1961, the Opportunity rover encountered three large iron meteorites within a few hundred meters of each other. In order of discovery, these rocks have been assigned the unofficial names Block Island, Shelter Island, an
Authors
James W. Ashley, M.P. Golombek, P. R. Christensen, S. W. Squyres, T.J. McCoy, C. Schroder, I. Fleischer, J. R. Johnson, Kenneth E. Herkenhoff, T. J. Parker
Meteorites at Meridiani Planum provide evidence for significant amounts of surface and near-surface water on early Mars
Six large iron meteorites have been discovered in the Meridiani Planum region of Mars by the Mars Exploration Rover Opportunity in a nearly 25 km-long traverse. Herein, we review and synthesize the available data to propose that the discovery and characteristics of the six meteorites could be explained as the result of their impact into a soft and wet surface, sometime during the Noachian or the H
Authors
Alberto G. Fairen, James M. Dohm, Victor R. Baker, Shane D. Thompson, William C. Mahaney, Kenneth E. Herkenhoff, J. Alexis P. Rodriguez, Alfonso F. Davila, Dirk Schulze-Makuch, M. Ramy El Maarry, Esther R. Uceda, Ricardo Amils, Hirdy Miyamoto, Kyeong J. Kim, Robert C. Anderson, Christopher P. McKay
Crater population and resurfacing of the Martian north polar layered deposits
Present‐day accumulation in the north polar layered deposits (NPLD) is thought to occur via deposition on the north polar residual cap. Understanding current mass balance in relation to current climate would provide insight into the climatic record of the NPLD. To constrain processes and rates of NPLD resurfacing, a search for craters was conducted using images from the Mars Reconnaissance Orbiter
Authors
Maria E. Banks, Shane Byrne, Kapil Galla, Alfred S. McEwen, Veronica J. Bray, Colin M. Dundas, Kathryn E. Fishbaugh, Kenneth E. Herkenhoff, Bruce C. Murray
Visible and near-infrared multispectral analysis of geochemically measured rock fragments at the Opportunity landing site in Meridiani Planum
We have used visible and near‐infrared Panoramic Camera (Pancam) spectral data acquired by the Opportunity rover to analyze 15 rock fragments at the Meridiani Planum landing site. These spectral results were then compared to geochemistry measurements made by the in situ instruments Mössbauer (MB) and Alpha Particle X‐ray Spectrometer (APXS) to determine the feasibility of mineralogic characterizat
Authors
Catherine M. Weitz, William H. Farrand, Jeffrey R. Johnson, Iris Fleischer, Christian Schröder, Aileen Yingst, Bradley L. Jolliff, Ralf Gellert, Jim Bell, Kenneth E. Herkenhoff, G. Klingelhoefer, Barbara Cohen, Wendy M. Calvin, Malcolm Rutherford, James W. Ashley
Properties and distribution of paired candidate stony meteorites at Meridiani Planum
The Mars Exploration Rover Opportunity investigated four rocks, informally dubbed Barberton, Santa Catarina, Santorini, and Kasos, that are possible stony meteorites. Their chemical and mineralogical composition is similar to the howardite, eucrite, and diogenite group but with additional metal, similar to mesosiderite silicate clasts. Because of their virtually identical composition and because t
Authors
Christian Schröder, Kenneth E. Herkenhoff, William H. Farrand, John E. Chappelow, Wei Wang, L.R. Nittler, James W. Ashley, Iris Fleischer, Ralf Gellert, Matthew P. Golombek, Jeffrey R. Johnson, G. Klingelhoefer, Ron Li, Richard V. Morris, Steven W. Squyres