Kenneth Edward Herkenhoff, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 149
Rocks of the Columbia Hills
The Mars Exploration Rover Spirit has identified five distinct rock types in the Columbia Hills of Gusev crater. Clovis Class rock is a poorly sorted clastic rock that has undergone substantial aqueous alteration. We interpret it to be aqueously altered ejecta deposits formed by impacts into basaltic materials. Wishstone Class rock is also a poorly sorted clastic rock that has a distinctive chemic
Authors
S. W. Squyres, R. E. Arvidson, D.L. Blaney, B. C. Clark, L. Crumpler, W. H. Farrand, S. Gorevan, Kenneth E. Herkenhoff, J. Hurowitz, A. Kusack, H.Y. McSween, D. W. Ming, R.V. Morris, S. W. Ruff, A. Wang, A. Yen
Evidence of phyllosilicates in Wooly Patch, an altered rock encountered at West Spur, Columbia Hills, by the Spirit rover in Gusev crater, Mars
On its traverse to Columbia Hills, the Mars Exploration Rover Spirit investigated an outcrop designated “Wooly Patch” that exhibited morphological, mineralogical, and geochemical characteristics at the extreme ends of ranges observed among rocks studied at West Spur, a westward projecting salient near the foot of the Columbia Hills, Gusev crater. The major‐element composition and Fe‐mineralogy, as
Authors
A. Wang, R.L. Korotev, B.L. Jolliff, L.A. Haskin, L. Crumpler, W. H. Farrand, Kenneth E. Herkenhoff, Jr. de Souza, A.G. Kusack, J.A. Hurowitz, N.J. Tosca
Soil grain analyses at Meridiani Planum, Mars
Grain‐size analyses of the soils at Meridiani Planum have been used to identify rock sources for the grains and provide information about depositional processes under past and current conditions. Basaltic sand, dust, millimeter‐size hematite‐rich spherules interpreted as concretions, spherule fragments, coated partially buried spherules, basalt fragments, sedimentary outcrop fragments, and centime
Authors
C.M. Weitz, R. C. Anderson, J.F. Bell, W. H. Farrand, Kenneth E. Herkenhoff, J. R. Johnson, B.L. Jolliff, R.V. Morris, S. W. Squyres, R.J. Sullivan
Sedimentary textures formed by aqueous processes, Erebus crater Meridiani Planum, Mars
New observations at Erebus crater (Olympia outcrop) by the Mars Exploration Rover Opportunity between sols 671 and 735 (a sol is a martian day) indicate that a diverse suite of primary and penecontemporaneous sedimentary structures is preserved in sulfate-rich bedrock. Centimeter-scale trough (festoon) cross-lamination is abundant, and is better expressed and thicker than previously described exam
Authors
J. Grotzinger, J. Bell, Kenneth E. Herkenhoff, J. Johnson, A. Knoll, E. McCartney, S. McLennan, J. Metz, Jeff Moore, S. Squyres, R. Sullivan, O. Ahronson, R. Arvidson, B. Joliff, M. Golombek, K. Lewis, T. Parker, J. Soderblom
Bedrock formation at Meridiani Planum
The Mars Exploration Rover Opportunity discovered sulphate-rich sedimentary rocks at Meridiani Planum on Mars, which are interpreted by McCollom and Hynek as altered volcanic rocks. However, their conclusions are derived from an incorrect representation of our depositional model, which is upheld by more recent Rover data. We contend that all the available data still support an aeolian and aqueous
Authors
S. W. Squyres, O. Aharonson, R. E. Arvidson, J.F. Bell, P. R. Christensen, B. C. Clark, J.A. Crisp, W. Farrand, T. Glotch, M.P. Golombek, J. Grant, J. Grotzinger, Kenneth E. Herkenhoff, J. R. Johnson, B.L. Jolliff, A.H. Knoll, S. M. McLennan, H.Y. McSween, Johnnie N. Moore, J. W. Rice, N. Tosca
Alkaline volcanic rocks from the Columbia Hills, Gusev crater, Mars
Irvine, Backstay, and Wishstone are the type specimens for three classes of fine-grained or fragmental, relatively unaltered rocks with distinctive thermal emission spectra, found as float on the flanks of the Columbia Hills. Chemical analyses indicate that these rocks are mildly alkaline basalt, trachybasalt, and tephrite, respectively. Their mineralogy consists of Na- and K-rich feldspar(s), low
Authors
H.Y. McSween, S. W. Ruff, R.V. Morris, J.F. Bell, Kenneth E. Herkenhoff, Ralf Gellert, K.R. Stockstill, L.L. Tornabene, S. W. Squyres, J.A. Crisp, P. R. Christensen, T.J. McCoy, D. W. Mittlefehldt, M. Schmidt
Two years at Meridiani Planum: Results from the Opportunity Rover
The Mars Exploration Rover Opportunity has spent more than 2 years exploring Meridiani Planum, traveling ∼8 kilometers and detecting features that reveal ancient environmental conditions. These include well-developed festoon (trough) cross-lamination formed in flowing liquid water, strata with smaller and more abundant hematite-rich concretions than those seen previously, possible relict “hopper c
Authors
S. W. Squyres, A.H. Knoll, R. E. Arvidson, B. C. Clark, J.P. Grotzinger, B.L. Jolliff, S. M. McLennan, N. Tosca, J.F. Bell, W. M. Calvin, W. H. Farrand, T.D. Glotch, M.P. Golombek, Kenneth E. Herkenhoff, J. R. Johnson, G. Klingelhofer, H.Y. McSween, A. S. Yen
Stratigraphy and sedimentology of a dry to wet eolian depositional system, Burns formation, Meridiani Planum, Mars
Outcrop exposures of sedimentary rocks at the Opportunity landing site (Meridiani Planum) form a set of genetically related strata defined here informally as the Burns formation. This formation can be subdivided into lower, middle, and upper units which, respectively, represent eolian dune, eolian sand sheet, and mixed eolian sand sheet and interdune facies associations. Collectively, these three
Authors
J. P. Grotzinger, R. E. Arvidson, J. F. III Bell, W. Calvin, B. C. Clark, D.A. Fike, M. Golombek, R. Greeley, A. Haldemann, Kenneth E. Herkenhoff, B. L. Jolliff, A. H. Knoll, M. Malin, S. M. McLennan, T. Parker, Laurence A. Soderblom, J. N. Sohl-Dickstein, S. W. Squyres, N.J. Tosca, W.A. Watters
An integrated view of the chemistry and mineralogy of martian soils
The mineralogical and elemental compositions of the martian soil are indicators of chemical and physical weathering processes. Using data from the Mars Exploration Rovers, we show that bright dust deposits on opposite sides of the planet are part of a global unit and not dominated by the composition of local rocks. Dark soil deposits at both sites have similar basaltic mineralogies, and could refl
Authors
A. S. Yen, Ralf Gellert, C. Schroder, R.V. Morris, J.F. Bell, A.T. Knudson, B. C. Clark, D. W. Ming, J.A. Crisp, R. E. Arvidson, D. Blaney, J. Brückner, P. R. Christensen, D.J. DesMarais, P.A. De Souza, T.E. Economou, A. Ghosh, B.C. Hahn, Kenneth E. Herkenhoff, L.A. Haskin, J.A. Hurowitz, B.L. Joliff, J. R. Johnson, G. Klingelhofer, M.B. Madsen, S. M. McLennan, H.Y. McSween, L. Richter, R. Rieder, D. Rodionov, Laurence A. Soderblom, S. W. Squyres, N.J. Tosca, A. Wang, M. Wyatt, J. Zipfel
Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater
Gusev crater was selected as the landing site for the Spirit rover because of the possibility that it once held a lake. Thus one of the rover's tasks was to search for evidence of lake sediments. However, the plains at the landing site were found to be covered by a regolith composed of olivine-rich basaltic rock and wind-blown 'global' dust. The analyses of three rock interiors exposed by the rock
Authors
L.A. Haskin, A. Wang, B.L. Jolliff, H.Y. McSween, B. C. Clark, D.J. Des Marais, S. M. McLennan, N.J. Tosca, J.A. Hurowitz, J.D. Farmer, A. Yen, S. W. Squyres, R. E. Arvidson, G. Klingelhofer, C. Schroder, P.A. De Souza, D. W. Ming, Ralf Gellert, J. Zipfel, J. Brückner, J.F. Bell, Kenneth E. Herkenhoff, P. R. Christensen, S. Ruff, D. Blaney, S. Gorevan, N.A. Cabrol, L. Crumpler, J. Grant, L. Soderblom
Aeolian processes at the Mars Exploration Rover Meridiani Planum landing site
The martian surface is a natural laboratory for testing our understanding of the physics of aeolian (wind-related) processes in an environment different from that of Earth. Martian surface markings and atmospheric opacity are time-variable, indicating that fine particles at the surface are mobilized regularly by wind. Regolith (unconsolidated surface material) at the Mars Exploration Rover Opportu
Authors
R. Sullivan, D. Banfield, J.F. Bell, W. Calvin, D. Fike, M. Golombek, R. Greeley, J. Grotzinger, Kenneth E. Herkenhoff, D. Jerolmack, M. Malin, D. Ming, Laurence A. Soderblom, S. W. Squyres, S. Thompson, W.A. Watters, C.M. Weitz, A. Yen
Mars exploration rover geologic traverse by the spirit rover in the plains of Gusev crater, Mars
The Spirit rover completed a 2.5 km traverse across gently sloping plains on the floor of Gusev crater from its location on the outer rim of Bonneville crater to the lower slopes of the Columbia Hills, Mars. Using the Athena suite of instruments in a transect approach, a systematic series of overlapping panoramic mosaics, remote sensing observations, surface analyses, and trenching operations docu
Authors
L.S. Crumpler, S. W. Squyres, R. E. Arvidson, J.F. Bell, D. Blaney, N.A. Cabrol, P. R. Christensen, D.J. DesMarais, J.D. Farmer, R. Fergason, M.P. Golombek, F.D. Grant, J. A. Grant, R. Greeley, B. Hahn, Kenneth E. Herkenhoff, J.A. Hurowitz, A.T. Knudson, G. A. Landis, R. Li, J. Maki, H.Y. McSween, D. W. Ming, J.E. Moersch, M.C. Payne, J.W. Rice, L. Richter, S. W. Ruff, M. Sims, S.D. Thompson, N. Tosca, A. Wang, P. Whelley, S.P. Wright, M.B. Wyatt
Science and Products
Filter Total Items: 149
Rocks of the Columbia Hills
The Mars Exploration Rover Spirit has identified five distinct rock types in the Columbia Hills of Gusev crater. Clovis Class rock is a poorly sorted clastic rock that has undergone substantial aqueous alteration. We interpret it to be aqueously altered ejecta deposits formed by impacts into basaltic materials. Wishstone Class rock is also a poorly sorted clastic rock that has a distinctive chemic
Authors
S. W. Squyres, R. E. Arvidson, D.L. Blaney, B. C. Clark, L. Crumpler, W. H. Farrand, S. Gorevan, Kenneth E. Herkenhoff, J. Hurowitz, A. Kusack, H.Y. McSween, D. W. Ming, R.V. Morris, S. W. Ruff, A. Wang, A. Yen
Evidence of phyllosilicates in Wooly Patch, an altered rock encountered at West Spur, Columbia Hills, by the Spirit rover in Gusev crater, Mars
On its traverse to Columbia Hills, the Mars Exploration Rover Spirit investigated an outcrop designated “Wooly Patch” that exhibited morphological, mineralogical, and geochemical characteristics at the extreme ends of ranges observed among rocks studied at West Spur, a westward projecting salient near the foot of the Columbia Hills, Gusev crater. The major‐element composition and Fe‐mineralogy, as
Authors
A. Wang, R.L. Korotev, B.L. Jolliff, L.A. Haskin, L. Crumpler, W. H. Farrand, Kenneth E. Herkenhoff, Jr. de Souza, A.G. Kusack, J.A. Hurowitz, N.J. Tosca
Soil grain analyses at Meridiani Planum, Mars
Grain‐size analyses of the soils at Meridiani Planum have been used to identify rock sources for the grains and provide information about depositional processes under past and current conditions. Basaltic sand, dust, millimeter‐size hematite‐rich spherules interpreted as concretions, spherule fragments, coated partially buried spherules, basalt fragments, sedimentary outcrop fragments, and centime
Authors
C.M. Weitz, R. C. Anderson, J.F. Bell, W. H. Farrand, Kenneth E. Herkenhoff, J. R. Johnson, B.L. Jolliff, R.V. Morris, S. W. Squyres, R.J. Sullivan
Sedimentary textures formed by aqueous processes, Erebus crater Meridiani Planum, Mars
New observations at Erebus crater (Olympia outcrop) by the Mars Exploration Rover Opportunity between sols 671 and 735 (a sol is a martian day) indicate that a diverse suite of primary and penecontemporaneous sedimentary structures is preserved in sulfate-rich bedrock. Centimeter-scale trough (festoon) cross-lamination is abundant, and is better expressed and thicker than previously described exam
Authors
J. Grotzinger, J. Bell, Kenneth E. Herkenhoff, J. Johnson, A. Knoll, E. McCartney, S. McLennan, J. Metz, Jeff Moore, S. Squyres, R. Sullivan, O. Ahronson, R. Arvidson, B. Joliff, M. Golombek, K. Lewis, T. Parker, J. Soderblom
Bedrock formation at Meridiani Planum
The Mars Exploration Rover Opportunity discovered sulphate-rich sedimentary rocks at Meridiani Planum on Mars, which are interpreted by McCollom and Hynek as altered volcanic rocks. However, their conclusions are derived from an incorrect representation of our depositional model, which is upheld by more recent Rover data. We contend that all the available data still support an aeolian and aqueous
Authors
S. W. Squyres, O. Aharonson, R. E. Arvidson, J.F. Bell, P. R. Christensen, B. C. Clark, J.A. Crisp, W. Farrand, T. Glotch, M.P. Golombek, J. Grant, J. Grotzinger, Kenneth E. Herkenhoff, J. R. Johnson, B.L. Jolliff, A.H. Knoll, S. M. McLennan, H.Y. McSween, Johnnie N. Moore, J. W. Rice, N. Tosca
Alkaline volcanic rocks from the Columbia Hills, Gusev crater, Mars
Irvine, Backstay, and Wishstone are the type specimens for three classes of fine-grained or fragmental, relatively unaltered rocks with distinctive thermal emission spectra, found as float on the flanks of the Columbia Hills. Chemical analyses indicate that these rocks are mildly alkaline basalt, trachybasalt, and tephrite, respectively. Their mineralogy consists of Na- and K-rich feldspar(s), low
Authors
H.Y. McSween, S. W. Ruff, R.V. Morris, J.F. Bell, Kenneth E. Herkenhoff, Ralf Gellert, K.R. Stockstill, L.L. Tornabene, S. W. Squyres, J.A. Crisp, P. R. Christensen, T.J. McCoy, D. W. Mittlefehldt, M. Schmidt
Two years at Meridiani Planum: Results from the Opportunity Rover
The Mars Exploration Rover Opportunity has spent more than 2 years exploring Meridiani Planum, traveling ∼8 kilometers and detecting features that reveal ancient environmental conditions. These include well-developed festoon (trough) cross-lamination formed in flowing liquid water, strata with smaller and more abundant hematite-rich concretions than those seen previously, possible relict “hopper c
Authors
S. W. Squyres, A.H. Knoll, R. E. Arvidson, B. C. Clark, J.P. Grotzinger, B.L. Jolliff, S. M. McLennan, N. Tosca, J.F. Bell, W. M. Calvin, W. H. Farrand, T.D. Glotch, M.P. Golombek, Kenneth E. Herkenhoff, J. R. Johnson, G. Klingelhofer, H.Y. McSween, A. S. Yen
Stratigraphy and sedimentology of a dry to wet eolian depositional system, Burns formation, Meridiani Planum, Mars
Outcrop exposures of sedimentary rocks at the Opportunity landing site (Meridiani Planum) form a set of genetically related strata defined here informally as the Burns formation. This formation can be subdivided into lower, middle, and upper units which, respectively, represent eolian dune, eolian sand sheet, and mixed eolian sand sheet and interdune facies associations. Collectively, these three
Authors
J. P. Grotzinger, R. E. Arvidson, J. F. III Bell, W. Calvin, B. C. Clark, D.A. Fike, M. Golombek, R. Greeley, A. Haldemann, Kenneth E. Herkenhoff, B. L. Jolliff, A. H. Knoll, M. Malin, S. M. McLennan, T. Parker, Laurence A. Soderblom, J. N. Sohl-Dickstein, S. W. Squyres, N.J. Tosca, W.A. Watters
An integrated view of the chemistry and mineralogy of martian soils
The mineralogical and elemental compositions of the martian soil are indicators of chemical and physical weathering processes. Using data from the Mars Exploration Rovers, we show that bright dust deposits on opposite sides of the planet are part of a global unit and not dominated by the composition of local rocks. Dark soil deposits at both sites have similar basaltic mineralogies, and could refl
Authors
A. S. Yen, Ralf Gellert, C. Schroder, R.V. Morris, J.F. Bell, A.T. Knudson, B. C. Clark, D. W. Ming, J.A. Crisp, R. E. Arvidson, D. Blaney, J. Brückner, P. R. Christensen, D.J. DesMarais, P.A. De Souza, T.E. Economou, A. Ghosh, B.C. Hahn, Kenneth E. Herkenhoff, L.A. Haskin, J.A. Hurowitz, B.L. Joliff, J. R. Johnson, G. Klingelhofer, M.B. Madsen, S. M. McLennan, H.Y. McSween, L. Richter, R. Rieder, D. Rodionov, Laurence A. Soderblom, S. W. Squyres, N.J. Tosca, A. Wang, M. Wyatt, J. Zipfel
Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater
Gusev crater was selected as the landing site for the Spirit rover because of the possibility that it once held a lake. Thus one of the rover's tasks was to search for evidence of lake sediments. However, the plains at the landing site were found to be covered by a regolith composed of olivine-rich basaltic rock and wind-blown 'global' dust. The analyses of three rock interiors exposed by the rock
Authors
L.A. Haskin, A. Wang, B.L. Jolliff, H.Y. McSween, B. C. Clark, D.J. Des Marais, S. M. McLennan, N.J. Tosca, J.A. Hurowitz, J.D. Farmer, A. Yen, S. W. Squyres, R. E. Arvidson, G. Klingelhofer, C. Schroder, P.A. De Souza, D. W. Ming, Ralf Gellert, J. Zipfel, J. Brückner, J.F. Bell, Kenneth E. Herkenhoff, P. R. Christensen, S. Ruff, D. Blaney, S. Gorevan, N.A. Cabrol, L. Crumpler, J. Grant, L. Soderblom
Aeolian processes at the Mars Exploration Rover Meridiani Planum landing site
The martian surface is a natural laboratory for testing our understanding of the physics of aeolian (wind-related) processes in an environment different from that of Earth. Martian surface markings and atmospheric opacity are time-variable, indicating that fine particles at the surface are mobilized regularly by wind. Regolith (unconsolidated surface material) at the Mars Exploration Rover Opportu
Authors
R. Sullivan, D. Banfield, J.F. Bell, W. Calvin, D. Fike, M. Golombek, R. Greeley, J. Grotzinger, Kenneth E. Herkenhoff, D. Jerolmack, M. Malin, D. Ming, Laurence A. Soderblom, S. W. Squyres, S. Thompson, W.A. Watters, C.M. Weitz, A. Yen
Mars exploration rover geologic traverse by the spirit rover in the plains of Gusev crater, Mars
The Spirit rover completed a 2.5 km traverse across gently sloping plains on the floor of Gusev crater from its location on the outer rim of Bonneville crater to the lower slopes of the Columbia Hills, Mars. Using the Athena suite of instruments in a transect approach, a systematic series of overlapping panoramic mosaics, remote sensing observations, surface analyses, and trenching operations docu
Authors
L.S. Crumpler, S. W. Squyres, R. E. Arvidson, J.F. Bell, D. Blaney, N.A. Cabrol, P. R. Christensen, D.J. DesMarais, J.D. Farmer, R. Fergason, M.P. Golombek, F.D. Grant, J. A. Grant, R. Greeley, B. Hahn, Kenneth E. Herkenhoff, J.A. Hurowitz, A.T. Knudson, G. A. Landis, R. Li, J. Maki, H.Y. McSween, D. W. Ming, J.E. Moersch, M.C. Payne, J.W. Rice, L. Richter, S. W. Ruff, M. Sims, S.D. Thompson, N. Tosca, A. Wang, P. Whelley, S.P. Wright, M.B. Wyatt