Kenneth Edward Herkenhoff, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 145
Surface ages and resurfacing rates of the Polar Layered Deposits on Mars
Interpretation of the polar stratigraphy of Mars in terms of global climate changes is complicated by the significant difference in surface ages between the north and south polar layered terrains inferred from crater statistics. We have reassessed the cratering record in both polar regions using Viking Orbiter and Mariner 9 images. No craters have been found in the north polar layered terrain, but
Authors
Kenneth E. Herkenhoff, Jeffrey J. Plaut
Results of the Imager for Mars Pathfinder windsock experiment
The Imager for Mars Pathfinder (IMP) windsock experiment measured wind speeds at three heights within 1.2 m of the Martian surface during Pathfinder landed operations. These wind data allowed direct measurement of near-surface wind profiles on Mars for the first time, including determination of aerodynamic roughness length and wind friction speeds. Winds were light during periods of windsock imagi
Authors
Robert Sullivan, Ronald Greeley, Michael Kraft, Gregory Wilson, Matthew P. Golombek, Kenneth E. Herkenhoff, James Murphy, Peter Smith
Observations of Phobos, Deimos, and bright stars with the Imager for Mars Pathfinder
The Imager for Mars Pathfinder (IMP) was used to observe several objects during the Martian night. The satellites, Phobos and Deimos, were observed on two occasions each, through the IMP geological filters covering the wavelength range 440 nm to 1 μm. The observations were converted to geometric albedo using triaxial ellipsoid models of the satellites and phase functions derived from Viking Orbite
Authors
Nick Thomas, D.T. Britt, Kenneth E. Herkenhoff, Scott L. Murchie, B. Semenov, H.U. Keller, P. H. Smith
Mars Pathfinder spectral measurements of Phobos and Deimos: Comparison with previous data
The Imager for Mars Pathfinder (IMP) acquired four spectra of parts of the sub‐Mars hemispheres of Phobos and Deimos. The measured region of Phobos is expected to be a mixture of the two spectral units identified on that satellite from Phobos 2 data, and the IMP spectra of Phobos are intermediate to the two units as expected. The derived geometric albedo is consistent with the value for that part
Authors
Scott L. Murchie, Nick Thomas, Daniel Britt, Kenneth E. Herkenhoff, James F. Bell
Overview of the Mars Pathfinder Mission: Launch through landing, surface operations, data sets, and science results
Mars Pathfinder successfully landed at Ares Vallis on July 4, 1997, deployed and navigated a small rover about 100 m clockwise around the lander, and collected data from three science instruments and ten technology experiments. The mission operated for three months and returned 2.3 Gbits of data, including over 16,500 lander and 550 rover images, 16 chemical analyses of rocks and soil, and 8.5 mil
Authors
M. P. Golombek, R. C. Anderson, J.R. Barnes, J. F. III Bell, N. T. Bridges, D.T. Britt, J. Brückner, R. A. Cook, D. Crisp, J.A. Crisp, T. Economou, W. M. Folkner, R. Greeley, R.M. Haberle, R.B. Hargraves, J.A. Harris, A. F. C. Haldemann, Kenneth E. Herkenhoff, S.F. Hviid, R. Jaumann, J. R. Johnson, P. H. Kallemeyn, H.U. Keller, Randolph L. Kirk, J. M. Knudsen, S. Larsen, M. T. Lemmon, M.B. Madsen, J.A. Magalhães, J.N. Maki, M.C. Malin, R. M. Manning, J. Matijevic, H.Y. McSween, H. J. Moore, S.L. Murchie, J.R. Murphy, T. J. Parker, R. Rieder, T.P. Rivellini, J. T. Schofield, A. Seiff, R.B. Singer, P. H. Smith, Laurence A. Soderblom, D.A. Spencer, C. R. Stoker, R. Sullivan, N. Thomas, S.W. Thurman, M.G. Tomasko, R. M. Vaughan, H. Wänke, A. W. Ward, G.R. Wilson
Preliminary results on photometric properties of materials at the Sagan Memorial Station, Mars
Reflectance measurements of selected rocks and soils over a wide range of illumination geometries obtained by the Imager for Mars Pathfinder (IMP) camera provide constraints on interpretations of the physical and mineralogical nature of geologic materials at the landing site. The data sets consist of (1) three small “photometric spot” subframed scenes, covering phase angles from 20° to 150°; (2) t
Authors
Jeffrey R. Johnson, Randolph L. Kirk, Laurence A. Soderblom, Lisa R. Gaddis, Robert J. Reid, Daniel T. Britt, Peter Smith, Mark T. Lemmon, Nicolas Thomas, James F. Bell, Nathan T. Bridges, Robert Anderson, Kenneth E. Herkenhoff, Justin N. Maki, Scott L. Murchie, Andreas Dummel, Ralf Jaumann, Frank Trauthan, Gabriele Arnold
Ventifacts at the Pathfinder landing site
About half of the rocks at the Mars Pathfinder Ares Vallis landing site appear to be ventifacts, rocks abraded by windborne particles. Comparable resolution images taken by the Imager for Mars Pathfinder (IMP) camera and the Viking landers show that ventifacts are more abundant at the Pathfinder site. The ventifacts occur in several forms, including rocks with faceted edges, finger‐like projection
Authors
N.T. Bridges, R. Greeley, A. F. C. Haldemann, Kenneth E. Herkenhoff, M. Kraft, T. J. Parker, A. W. Ward
Aeolian features and processes at the Mars Pathfinder landing site
The Mars Pathfinder landing site contains abundant features attributed to aeolian, or wind, processes. These include wind tails, drift deposits, duneforms of various types, ripplelike features, and ventifacts (the first clearly seen on Mars). Many of these features are consistant with formation involving sand-size particles. Although some features, such as dunes, could develop from saltating sand-
Authors
Ronald Greeley, Michael Kraft, Robert Sullivan, Gregory Wilson, Nathan Bridges, Kenneth E. Herkenhoff, Ruslan O. Kuzmin, Michael Malin, Wes Ward
Imager for Mars Pathfinder (IMP) image calibration
The Imager for Mars Pathfinder returned over 16,000 high-quality images from the surface of Mars. The camera was well-calibrated in the laboratory, with <5% radiometric uncertainty. The photometric properties of two radiometric targets were also measured with 3% uncertainty. Several data sets acquired during the cruise and on Mars confirm that the system operated nominally throughout the course of
Authors
R.J. Reid, P. H. Smith, M. Lemmon, R. Tanner, M. Burkland, E. Wegryn, J. Weinberg, R. Marcialis, D.T. Britt, N. Thomas, R. Kramm, A. Dummel, D. Crowe, B.J. Bos, J.F. Bell, P. Rueffer, F. Gliem, J. R. Johnson, J.N. Maki, Kenneth E. Herkenhoff, Robert B. Singer
Geology of the Upheaval Dome impact structure, southeast Utah
Two vastly different phenomena, impact and salt diapirism, have been proposed for the origin of Upheaval Dome, a spectacular scenic feature in southeast Utah. Detailed geologic mapping and seismic refraction data indicate that the dome originated by collapse of a transient cavity formed by impact. Evidence is as follows: (1) sedimentary strata in the center of the structure are pervasively imbrica
Authors
Bryan J. Kriens, Eugene M. Shoemaker, Kenneth E. Herkenhoff
Dark material in the polar layered deposits and dunes on Mars
Viking infrared thermal mapping and bistatic radar data suggest that the bulk density of the north polar erg material is much lower than that of the average Martian surface or of dark dunes at lower latitudes. We have derived a thermal inertia of 245–280 J m−2 s−1/2 K−1 (5.9–6.7×10−3 cal cm−2 s−1/2 K−1) for the Proctor dune field and 25–150 J m−2 s−1/2 K−1 (0.6–3.6×10−3cal cm−2 s−1/2 K−1) for the
Authors
Kenneth E. Herkenhoff, Ashwin R. Vasavada
Results from the Mars Pathfinder camera
Images of the martian surface returned by the Imager for Mars Pathfinder (IMP) show a complex surface of ridges and troughs covered by rocks that have been transported and modified by fluvial, aeolian, and impact processes. Analysis of the spectral signatures in the scene (at 440- to 1000-nanometer wavelength) reveal three types of rock and four classes of soil. Upward-looking IMP images of the pr
Authors
P. H. Smith, J. F. III Bell, N. T. Bridges, D.T. Britt, Lisa R. Gaddis, R. Greeley, H.U. Keller, Kenneth E. Herkenhoff, R. Jaumann, J. R. Johnson, Randolph L. Kirk, M. Lemmon, J.N. Maki, M.C. Malin, S.L. Murchie, J. Oberst, T. J. Parker, R.J. Reid, R.M. Sablotny, Laurence A. Soderblom, C. Stoker, R. Sullivan, N. Thomas, M.G. Tomasko, W. Ward, E. Wegryn
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Filter Total Items: 145
Surface ages and resurfacing rates of the Polar Layered Deposits on Mars
Interpretation of the polar stratigraphy of Mars in terms of global climate changes is complicated by the significant difference in surface ages between the north and south polar layered terrains inferred from crater statistics. We have reassessed the cratering record in both polar regions using Viking Orbiter and Mariner 9 images. No craters have been found in the north polar layered terrain, butAuthorsKenneth E. Herkenhoff, Jeffrey J. PlautResults of the Imager for Mars Pathfinder windsock experiment
The Imager for Mars Pathfinder (IMP) windsock experiment measured wind speeds at three heights within 1.2 m of the Martian surface during Pathfinder landed operations. These wind data allowed direct measurement of near-surface wind profiles on Mars for the first time, including determination of aerodynamic roughness length and wind friction speeds. Winds were light during periods of windsock imagiAuthorsRobert Sullivan, Ronald Greeley, Michael Kraft, Gregory Wilson, Matthew P. Golombek, Kenneth E. Herkenhoff, James Murphy, Peter SmithObservations of Phobos, Deimos, and bright stars with the Imager for Mars Pathfinder
The Imager for Mars Pathfinder (IMP) was used to observe several objects during the Martian night. The satellites, Phobos and Deimos, were observed on two occasions each, through the IMP geological filters covering the wavelength range 440 nm to 1 μm. The observations were converted to geometric albedo using triaxial ellipsoid models of the satellites and phase functions derived from Viking OrbiteAuthorsNick Thomas, D.T. Britt, Kenneth E. Herkenhoff, Scott L. Murchie, B. Semenov, H.U. Keller, P. H. SmithMars Pathfinder spectral measurements of Phobos and Deimos: Comparison with previous data
The Imager for Mars Pathfinder (IMP) acquired four spectra of parts of the sub‐Mars hemispheres of Phobos and Deimos. The measured region of Phobos is expected to be a mixture of the two spectral units identified on that satellite from Phobos 2 data, and the IMP spectra of Phobos are intermediate to the two units as expected. The derived geometric albedo is consistent with the value for that partAuthorsScott L. Murchie, Nick Thomas, Daniel Britt, Kenneth E. Herkenhoff, James F. BellOverview of the Mars Pathfinder Mission: Launch through landing, surface operations, data sets, and science results
Mars Pathfinder successfully landed at Ares Vallis on July 4, 1997, deployed and navigated a small rover about 100 m clockwise around the lander, and collected data from three science instruments and ten technology experiments. The mission operated for three months and returned 2.3 Gbits of data, including over 16,500 lander and 550 rover images, 16 chemical analyses of rocks and soil, and 8.5 milAuthorsM. P. Golombek, R. C. Anderson, J.R. Barnes, J. F. III Bell, N. T. Bridges, D.T. Britt, J. Brückner, R. A. Cook, D. Crisp, J.A. Crisp, T. Economou, W. M. Folkner, R. Greeley, R.M. Haberle, R.B. Hargraves, J.A. Harris, A. F. C. Haldemann, Kenneth E. Herkenhoff, S.F. Hviid, R. Jaumann, J. R. Johnson, P. H. Kallemeyn, H.U. Keller, Randolph L. Kirk, J. M. Knudsen, S. Larsen, M. T. Lemmon, M.B. Madsen, J.A. Magalhães, J.N. Maki, M.C. Malin, R. M. Manning, J. Matijevic, H.Y. McSween, H. J. Moore, S.L. Murchie, J.R. Murphy, T. J. Parker, R. Rieder, T.P. Rivellini, J. T. Schofield, A. Seiff, R.B. Singer, P. H. Smith, Laurence A. Soderblom, D.A. Spencer, C. R. Stoker, R. Sullivan, N. Thomas, S.W. Thurman, M.G. Tomasko, R. M. Vaughan, H. Wänke, A. W. Ward, G.R. WilsonPreliminary results on photometric properties of materials at the Sagan Memorial Station, Mars
Reflectance measurements of selected rocks and soils over a wide range of illumination geometries obtained by the Imager for Mars Pathfinder (IMP) camera provide constraints on interpretations of the physical and mineralogical nature of geologic materials at the landing site. The data sets consist of (1) three small “photometric spot” subframed scenes, covering phase angles from 20° to 150°; (2) tAuthorsJeffrey R. Johnson, Randolph L. Kirk, Laurence A. Soderblom, Lisa R. Gaddis, Robert J. Reid, Daniel T. Britt, Peter Smith, Mark T. Lemmon, Nicolas Thomas, James F. Bell, Nathan T. Bridges, Robert Anderson, Kenneth E. Herkenhoff, Justin N. Maki, Scott L. Murchie, Andreas Dummel, Ralf Jaumann, Frank Trauthan, Gabriele ArnoldVentifacts at the Pathfinder landing site
About half of the rocks at the Mars Pathfinder Ares Vallis landing site appear to be ventifacts, rocks abraded by windborne particles. Comparable resolution images taken by the Imager for Mars Pathfinder (IMP) camera and the Viking landers show that ventifacts are more abundant at the Pathfinder site. The ventifacts occur in several forms, including rocks with faceted edges, finger‐like projectionAuthorsN.T. Bridges, R. Greeley, A. F. C. Haldemann, Kenneth E. Herkenhoff, M. Kraft, T. J. Parker, A. W. WardAeolian features and processes at the Mars Pathfinder landing site
The Mars Pathfinder landing site contains abundant features attributed to aeolian, or wind, processes. These include wind tails, drift deposits, duneforms of various types, ripplelike features, and ventifacts (the first clearly seen on Mars). Many of these features are consistant with formation involving sand-size particles. Although some features, such as dunes, could develop from saltating sand-AuthorsRonald Greeley, Michael Kraft, Robert Sullivan, Gregory Wilson, Nathan Bridges, Kenneth E. Herkenhoff, Ruslan O. Kuzmin, Michael Malin, Wes WardImager for Mars Pathfinder (IMP) image calibration
The Imager for Mars Pathfinder returned over 16,000 high-quality images from the surface of Mars. The camera was well-calibrated in the laboratory, with <5% radiometric uncertainty. The photometric properties of two radiometric targets were also measured with 3% uncertainty. Several data sets acquired during the cruise and on Mars confirm that the system operated nominally throughout the course ofAuthorsR.J. Reid, P. H. Smith, M. Lemmon, R. Tanner, M. Burkland, E. Wegryn, J. Weinberg, R. Marcialis, D.T. Britt, N. Thomas, R. Kramm, A. Dummel, D. Crowe, B.J. Bos, J.F. Bell, P. Rueffer, F. Gliem, J. R. Johnson, J.N. Maki, Kenneth E. Herkenhoff, Robert B. SingerGeology of the Upheaval Dome impact structure, southeast Utah
Two vastly different phenomena, impact and salt diapirism, have been proposed for the origin of Upheaval Dome, a spectacular scenic feature in southeast Utah. Detailed geologic mapping and seismic refraction data indicate that the dome originated by collapse of a transient cavity formed by impact. Evidence is as follows: (1) sedimentary strata in the center of the structure are pervasively imbricaAuthorsBryan J. Kriens, Eugene M. Shoemaker, Kenneth E. HerkenhoffDark material in the polar layered deposits and dunes on Mars
Viking infrared thermal mapping and bistatic radar data suggest that the bulk density of the north polar erg material is much lower than that of the average Martian surface or of dark dunes at lower latitudes. We have derived a thermal inertia of 245–280 J m−2 s−1/2 K−1 (5.9–6.7×10−3 cal cm−2 s−1/2 K−1) for the Proctor dune field and 25–150 J m−2 s−1/2 K−1 (0.6–3.6×10−3cal cm−2 s−1/2 K−1) for theAuthorsKenneth E. Herkenhoff, Ashwin R. VasavadaResults from the Mars Pathfinder camera
Images of the martian surface returned by the Imager for Mars Pathfinder (IMP) show a complex surface of ridges and troughs covered by rocks that have been transported and modified by fluvial, aeolian, and impact processes. Analysis of the spectral signatures in the scene (at 440- to 1000-nanometer wavelength) reveal three types of rock and four classes of soil. Upward-looking IMP images of the prAuthorsP. H. Smith, J. F. III Bell, N. T. Bridges, D.T. Britt, Lisa R. Gaddis, R. Greeley, H.U. Keller, Kenneth E. Herkenhoff, R. Jaumann, J. R. Johnson, Randolph L. Kirk, M. Lemmon, J.N. Maki, M.C. Malin, S.L. Murchie, J. Oberst, T. J. Parker, R.J. Reid, R.M. Sablotny, Laurence A. Soderblom, C. Stoker, R. Sullivan, N. Thomas, M.G. Tomasko, W. Ward, E. Wegryn - News