Dr. John W Keller

Dr. John W Keller

  • RESEARCH AST, FIELDS & PARTICLES
  • 301.286.3871 | 301.286.0212
  • NASA/GSFC
  • Mail Code: 691
  • Greenbelt , MD 20771
  • Employer: NASA
  • Research Interests

    Space Plasma Physics Instrumentation and Lunar Remote Sensing using plasma instrumentation and relevant laboratory measurements of particle surface interactions. Atomic and Molecular Physics of Astrophysical Significance


    Positions/Employment

    2012 - 2018

    Project Scientist Lunar Reconnaissance Orbiter Mission

    NASA/GSFC, Greenbelt MD
    1986 - Present

    Astrophysicist, Solar System Exploration Division

    NASA/GSFC, Greenbelt MD
    2006 - 2012

    Deputy Project Scientist Lunar Reconnaissance Orbiter

    NASA/GSFC, Greenbelt MD
    1985 - 1986

    Postdoctoral research associate

    Dept. of Chemistry, University of Maryland, College Park, MD

    Education

    B.S. in mathematics, Texas Tech University, 1977
    M.S. in physical chemistry, Texas Tech University, 1979
    Ph.D. in physical chemistry, University of Maryland, 1984

    Professional Societies

    American Physical Society, 1983 - Present
    American Geophysical Union, 1990 - Present

    Professional Service

    Guest Editor for Icarus Special Issue on the Lunar Reconnaissance Orbiter Mission
    Science Organizing Committee for the 2013 Lunar Science Forum
    Member of the Independent Review Team for the Osiris Rex Mission, 2012.
    Associate Editor, Results of the Lunar Reconnaissance Orbiter Mission, J. Geo. Res., AGU 2012.
    Editor, Lunar Reconnaissance Orbiter Mission, Space Science Reviews, Vol. 150 Issues 1-4, Springer 2010,

    Awards

    NASA Exceptional Achievement Medal - 2010
    NASA Exceptional Achievement Outreach - The LRO Exhibit Team - 2013
    Special Act Award - Osiris-Rex GSRT - 2012
    NASA Group Achievement Award - The LRO Missions Operations Team - 2011
     

    Selected Publications

    Refereed

    Farrell, W. M., J. L. McLain, M. R. Collier, and J. W. Keller. 2017. "The Martian dust devil electron avalanche: Laboratory measurements of the E-field fortifying effects of dust-electron absorption." Icarus, 297: 90-96 [10.1016/j.icarus.2017.06.001]

    Vaisberg, O., J. J. Berthellier, T. Moore, et al. L. Avanov, F. Leblanc, P. Moiseev, D. Moiseenko, J. Becker, M. Collier, G. Laky, J. Keller, G. Koynash, H. Lichtenneger, A. Leibov, R. Zhuravlev, A. Shestakov, J. Burch, D. McComas, S. Shuvalov, D. Chornay, and K. Torkar. 2016. "The 2 pi charged particles analyzer: All-sky camera concept and development for space missions." Journal of Geophysical Research-Space Physics, 121 (12): 11750-11765 [10.1002/2016ja022568]

    Keller, J., N. Petro, and R. Vondrak. 2016. "The Lunar Reconnaissance Orbiter Mission – Six years of science and exploration at the Moon." Icarus, 273: 2-24 [10.1016/j.icarus.2015.11.024]

    Collier, M. R., R. R. Vondrak, R. P. Hoyt, et al. M. A. Mesarch, W. M. Farrell, J. W. Keller, P. E. Clark, N. E. Petro, and K.-J. Hwang. 2016. "Tethered lunar subsatellites for multipoint and low altitude measurements." Acta Astronautica, 128: 464-472 [10.1016/j.actaastro.2016.07.047]

    Farrell, W. M., J. L. McLain, M. R. Collier, et al. J. W. Keller, T. J. Jackson, and G. T. Delory. 2015. "Is the electron avalanche process in a martian dust devil self-quenching?" Icarus, 254: 333-337 [10.1016/j.icarus.2015.04.003]

    Collier, M. R., F. S. Porter, D. G. Sibeck, et al. J. A. Carter, M. P. Chiao, D. J. Chornay, T. E. Cravens, M. Galeazzi, J. W. Keller, D. Koutroumpa, J. Kujawski, K. Kuntz, A. M. Read, I. P. Robertson, S. Sembay, S. L. Snowden, N. Thomas, Y. Uprety, and B. M. Walsh. 2015. "Invited Article: First flight in space of a wide-field-of-view soft x-ray imager using lobster-eye optics: Instrument description and initial flight results." Review of Scientific Instruments, 86 (7): [10.1063/1.4927259]

    Collier, M. R., F. S. Porter, D. G. Sibeck, et al. J. A. Carter, M. P. Chiao, D. J. Chornay, T. Cravens, M. Galeazzi, J. W. Keller, D. Koutroumpa, K. Kuntz, A. M. Read, I. P. Robertson, S. Sembay, S. Snowden, and N. Thomas. 2012. "Prototyping a global soft X-ray imaging instrument for heliophysics, planetary science, and astrophysics science." Astronomische Nachrichten, 333 (4): 378-382 [10.1002/asna.201211662]

    Vondrak, R., J. Keller, G. Chin, and J. Garvin. 2010. "Lunar Reconnaissance Orbiter (LRO): Observations for Lunar Exploration and Science." Space Science Reviews, 150: 7 [Full Text (Link)] [10.1007/s11214-010-9631-5]

    Chin, G., S. Brylow, M. Foote, et al. J. Garvin, J. Kasper, J. Keller, M. Litvak, I. Mitrofanov, D. Paige, K. Raney, M. Robinson, A. Sanin, D. Smith, H. Spence, P. Spudis, S. A. Stern, and M. Zuber. 2007. "Lunar Reconnaissance Orbiter Overview: The Instrument Suite and Mission." Space Science Reviews, 129: 391 [Full Text (Link)] [10.1007/s11214-007-9153-y]

    Vaisberg, O. L., L. A. Avanov, A. V. Leibov, et al. V. N. Smirnov, J. Keller, T. Moore, D. Chornay, M. Collier, V. S. Troshin, and V. D. Myagkikh. 2005. "A panoramic plasma spectrometer: An all-sky camera for charged particles." Cosmic Research, 43 (5): 373-376 [10.1007/s10604-005-0058-9]

    Keller, J. W. 2003. "Optimization code for an electrostatic mirror charged-particle optical system." Measurement Science and Technology, 14 (9): N64-N68 [10.1088/0957-0233/14/9/403]

    Collier, M. R., D. J. Chornay, J. W. Keller, et al. M. Coplan, N. J. Dionne, B. E. Marji, F. Herrero, J. Hirman, J. Houser, J. Moore, and J. A. Slavin. 2003. "Tomographic imaging of electron distributions: Leveraging computing power advances to produce inexpensive, low-power, lightweight, and robust instrumentation." Review of Scientific Instruments, 74 (2): 1002-1007 [10.1063/1.1532543]

    Keller, J. W., M. A. Coplan, J. E. Lorenz, and K. W. Ogilve. 2001. "New concept for the measurement of energetic neutral atom composition and the imaging of their sources." Solar and Galactic Composition, 598: 291-296.

    Moore, T. E., D. J. Chornay, M. R. Collier, et al. F. A. Herrero, J. Johnson, M. A. Johnson, J. W. Keller, J. F. Laudadio, J. F. Lobell, K. W. Ogilvie, P. Rozmarynowski, S. A. Fuselier, A. G. Ghielmetti, E. Hertzberg, D. C. Hamilton, R. Lundgren, P. Wilson, P. Walpole, T. M. Stephen, B. L. Peko, B. Van Zyl, P. Wurz, J. M. Quinn, and G. R. Wilson. 2000. "The low-energy neutral atom imager for IMAGE." Space Science Reviews, v 91, Issue 1/2, p 155-195 (2000), 91: 155 [Full Text (Link)]

    Keller, J. W., D. J. Chornay, F. H. Hunsaker, K. W. Ogilvie, and M. A. Coplan. 1999. "Gated time-of-flight plasma composition analyzer for space physics research." Review of Scientific Instruments, 70 (7): 3167-3172 [10.1063/1.1149881]

    Chornay, D. J., F. H. Hunsaker, and J. W. Keller. 1997. "Evaluation of an elliptical grid mirror electrostatic analyzer for space applications." Review of Scientific Instruments, 68 (3): 1604-1608 [10.1063/1.1147933]

    Steinberg, J. T., A. J. Lazarus, K. W. Ogilvie, et al. R. Lepping, J. Byrnes, D. J. Chornay, J. Keller, R. B. Torbert, D. Bodet, and G. J. Needell. 1996. "WIND measurements of proton and alpha particle flow and number density." Solar Wind Eight - Proceedings of the Eighth International Solar Wind Conference, 203-203.

    Scudder, J., F. Hunsacker, G. Miller, et al. J. Lobell, T. Zawistowski, K. Ogilvie, J. Keller, D. Chornay, F. Herrero, R. Fitzenreiter, D. Fairfield, J. Needell, D. Bodet, J. Googins, C. Kletzing, R. Torbert, J. Vandiver, R. Bentley, W. Fillius, C. McIlwain, E. Whipple, and A. Korth. 1995. "HYDRA-A3-DIMENSIONAL ELECTRON AND ION HOT PLASMA INSTRUMENT FOR THE POLAR SPACECRAFT OF THE GGS MISSION." Space Science Reviews, 71 (1-4): 459-495 [10.1007/bf00751338]

    Ogilvie, K. W., D. J. Chornay, R. J. Fritzenreiter, et al. F. Hunsaker, J. Keller, J. Lobell, G. Miller, J. D. Scudder, E. C. Sittler, R. B. Torbert, D. Bodet, G. Needell, A. J. Lazarus, J. T. Steinberg, and J. H. Tappan. 1995. "SWE, A COMPREHENSIVE PLASMA INSTRUMENT FOR THE WIND SPACECRAFT." Space Science Reviews, 71 (1-4): 55-77 [10.1007/bf00751326]

    Ju, N. J., A. Bulgac, and J. W. Keller. 1994. "EXCITATION OF COLLECTIVE STATES IN FULLERENES." Computational Materials Science, 2 (3-4): 615-627 [10.1016/0927-0256(94)90097-3]

    Ju, N. J., A. Bulgac, and J. W. Keller. 1993. "EXCITATION OF COLLECTIVE PLASMON STATES IN FULLERENES." Physical Review B, 48 (12): 9071-9079 [10.1103/PhysRevB.48.9071]

    Keller, J. W., M. A. Coplan, and R. Goruganthu. 1992. "ELECTRON-ENERGY LOSS SPECTRA OF POLYCYCLIC AROMATIC-HYDROCARBONS." Astrophysical Journal, 391 (2): 872-875 [10.1086/171396]

    Keller, J. W., and M. A. Coplan. 1992. "ELECTRON-ENERGY LOSS SPECTROSCOPY OF C-60." Chemical Physics Letters, 193 (1-3): 89-92 [10.1016/0009-2614(92)85687-6]

    Keller, J. W., R. B. Torbert, and J. Vandiver. 1991. "HIGH-SPEED PITCH ANGLE SORTER." Review of Scientific Instruments, 62 (5): 1353-1355 [10.1063/1.1142498]

    Keller, J. W., K. W. Ogilvie, J. W. Boring, and R. W. McKemie. 1991. "MEASUREMENT OF THE SECONDARY-EMISSION YIELD OF ELECTRONS FROM THIN CARBON FOILS AFTER PASSAGE OF LOW-ENERGY IONS." Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms, 61 (3): 291-294 [10.1016/0168-583x(91)95632-n]

    Keller, J. W., W. T. Hill, D. L. Ederer, T. J. Gil, and P. W. Langhoff. 1987. "POLARIZED FLUORESCENCE SPECTROSCOPY OF O-2+." Journal of Chemical Physics, 87 (6): 3299-3303 [10.1063/1.453023]

    Keller, J., R. Bonanno, M. X. Wang, M. S. Devries, and J. Weiner. 1986. "DETERMINATION OF INTERNAL ENERGY-DISTRIBUTION IN NA-2+ PRODUCED BY ASSOCIATIVE-IONIZATION COLLISIONS IN CROSSED BEAMS." Physical Review A, 33 (3): 1612-1618 [10.1103/PhysRevA.33.1612]

    Keller, J., and J. Weiner. 1984. "PRODUCTION OF BA+ IN A 2-PHOTON RADIATIVE COLLISION IN CROSSED NA-BA BEAMS." Physical Review A, 29 (4): 2230-2231 [10.1103/PhysRevA.29.2230]

    Keller, J., and J. Weiner. 1984. "MULTIPHOTON IONIZATION SPECTROSCOPY OF THE SODIUM DIMER." Physical Review A, 30 (1): 213-219 [10.1103/PhysRevA.30.213]

    Keller, J., and J. Weiner. 1984. "DIRECT MEASUREMENT OF THE POTENTIAL-BARRIER HEIGHT IN THE B1-PI-MU-STATE OF THE SODIUM DIMER." Physical Review A, 29 (5): 2943-2945 [10.1103/PhysRevA.29.2943]

    Keller, J., and J. Weiner. 1984. "DIRECT MEASUREMENT OF THE POTENTIAL BARRIER HEIGHT IN THE B1-PI-MU STATE OF SODIUM DIMER." Abstracts of Papers of the American Chemical Society, 188 (AUG): 210-PHYS.

    Non-Refereed

    Roark, J. H., J. W. Keller, F. Niepold, et al. S. E. Sakimoto, S. Stockman, and H. V. Frey. 2003. "3-Dimensional Topographic Models of Geologic Features for the Classroom." GSA Annual Meeting, Seattle WA., abstract 66476.

    Selected Publications

    Refereed

    Farrell, W. M., J. L. McLain, M. R. Collier, and J. W. Keller. 2017. "The Martian dust devil electron avalanche: Laboratory measurements of the E-field fortifying effects of dust-electron absorption." Icarus 297 90-96 [10.1016/j.icarus.2017.06.001]

    Vaisberg, O., J. J. Berthellier, T. Moore, et al. L. Avanov, F. Leblanc, P. Moiseev, D. Moiseenko, J. Becker, M. Collier, G. Laky, J. Keller, G. Koynash, H. Lichtenneger, A. Leibov, R. Zhuravlev, A. Shestakov, J. Burch, D. McComas, S. Shuvalov, D. Chornay, and K. Torkar. 2016. "The 2 pi charged particles analyzer: All-sky camera concept and development for space missions." Journal of Geophysical Research-Space Physics 121 (12): 11750-11765 [10.1002/2016ja022568]

    Keller, J., N. Petro, and R. Vondrak. 2016. "The Lunar Reconnaissance Orbiter Mission – Six years of science and exploration at the Moon." Icarus 273 2-24 [10.1016/j.icarus.2015.11.024]

    Collier, M. R., R. R. Vondrak, R. P. Hoyt, et al. M. A. Mesarch, W. M. Farrell, J. W. Keller, P. E. Clark, N. E. Petro, and K.-J. Hwang. 2016. "Tethered lunar subsatellites for multipoint and low altitude measurements." Acta Astronautica 128 464-472 [10.1016/j.actaastro.2016.07.047]

    Farrell, W. M., J. L. McLain, M. R. Collier, et al. J. W. Keller, T. J. Jackson, and G. T. Delory. 2015. "Is the electron avalanche process in a martian dust devil self-quenching?" Icarus 254 333-337 [10.1016/j.icarus.2015.04.003]

    Collier, M. R., F. S. Porter, D. G. Sibeck, et al. J. A. Carter, M. P. Chiao, D. J. Chornay, T. E. Cravens, M. Galeazzi, J. W. Keller, D. Koutroumpa, J. Kujawski, K. Kuntz, A. M. Read, I. P. Robertson, S. Sembay, S. L. Snowden, N. Thomas, Y. Uprety, and B. M. Walsh. 2015. "Invited Article: First flight in space of a wide-field-of-view soft x-ray imager using lobster-eye optics: Instrument description and initial flight results." Review of Scientific Instruments 86 (7): [10.1063/1.4927259]

    Collier, M. R., F. S. Porter, D. G. Sibeck, et al. J. A. Carter, M. P. Chiao, D. J. Chornay, T. Cravens, M. Galeazzi, J. W. Keller, D. Koutroumpa, K. Kuntz, A. M. Read, I. P. Robertson, S. Sembay, S. Snowden, and N. Thomas. 2012. "Prototyping a global soft X-ray imaging instrument for heliophysics, planetary science, and astrophysics science." Astronomische Nachrichten 333 (4): 378-382 [10.1002/asna.201211662]

    Vondrak, R., J. Keller, G. Chin, and J. Garvin. 2010. "Lunar Reconnaissance Orbiter (LRO): Observations for Lunar Exploration and Science." Space Science Reviews 150 7 [Full Text (Link)] [10.1007/s11214-010-9631-5]

    Chin, G., S. Brylow, M. Foote, et al. J. Garvin, J. Kasper, J. Keller, M. Litvak, I. Mitrofanov, D. Paige, K. Raney, M. Robinson, A. Sanin, D. Smith, H. Spence, P. Spudis, S. A. Stern, and M. Zuber. 2007. "Lunar Reconnaissance Orbiter Overview: The Instrument Suite and Mission." Space Science Reviews 129 391 [Full Text (Link)] [10.1007/s11214-007-9153-y]

    Vaisberg, O. L., L. A. Avanov, A. V. Leibov, et al. V. N. Smirnov, J. Keller, T. Moore, D. Chornay, M. Collier, V. S. Troshin, and V. D. Myagkikh. 2005. "A panoramic plasma spectrometer: An all-sky camera for charged particles." Cosmic Research 43 (5): 373-376 [10.1007/s10604-005-0058-9]

    Keller, J. W. 2003. "Optimization code for an electrostatic mirror charged-particle optical system." Measurement Science and Technology 14 (9): N64-N68 [10.1088/0957-0233/14/9/403]

    Collier, M. R., D. J. Chornay, J. W. Keller, et al. M. Coplan, N. J. Dionne, B. E. Marji, F. Herrero, J. Hirman, J. Houser, J. Moore, and J. A. Slavin. 2003. "Tomographic imaging of electron distributions: Leveraging computing power advances to produce inexpensive, low-power, lightweight, and robust instrumentation." Review of Scientific Instruments 74 (2): 1002-1007 [10.1063/1.1532543]

    Keller, J. W., M. A. Coplan, J. E. Lorenz, and K. W. Ogilve. 2001. "New concept for the measurement of energetic neutral atom composition and the imaging of their sources." Solar and Galactic Composition 598 291-296

    Moore, T. E., D. J. Chornay, M. R. Collier, et al. F. A. Herrero, J. Johnson, M. A. Johnson, J. W. Keller, J. F. Laudadio, J. F. Lobell, K. W. Ogilvie, P. Rozmarynowski, S. A. Fuselier, A. G. Ghielmetti, E. Hertzberg, D. C. Hamilton, R. Lundgren, P. Wilson, P. Walpole, T. M. Stephen, B. L. Peko, B. Van Zyl, P. Wurz, J. M. Quinn, and G. R. Wilson. 2000. "The low-energy neutral atom imager for IMAGE." Space Science Reviews, v 91, Issue 1/2, p 155-195 (2000) 91 155 [Full Text (Link)]

    Keller, J. W., D. J. Chornay, F. H. Hunsaker, K. W. Ogilvie, and M. A. Coplan. 1999. "Gated time-of-flight plasma composition analyzer for space physics research." Review of Scientific Instruments 70 (7): 3167-3172 [10.1063/1.1149881]

    Chornay, D. J., F. H. Hunsaker, and J. W. Keller. 1997. "Evaluation of an elliptical grid mirror electrostatic analyzer for space applications." Review of Scientific Instruments 68 (3): 1604-1608 [10.1063/1.1147933]

    Steinberg, J. T., A. J. Lazarus, K. W. Ogilvie, et al. R. Lepping, J. Byrnes, D. J. Chornay, J. Keller, R. B. Torbert, D. Bodet, and G. J. Needell. 1996. "WIND measurements of proton and alpha particle flow and number density." Solar Wind Eight - Proceedings of the Eighth International Solar Wind Conference 203-203

    Scudder, J., F. Hunsacker, G. Miller, et al. J. Lobell, T. Zawistowski, K. Ogilvie, J. Keller, D. Chornay, F. Herrero, R. Fitzenreiter, D. Fairfield, J. Needell, D. Bodet, J. Googins, C. Kletzing, R. Torbert, J. Vandiver, R. Bentley, W. Fillius, C. McIlwain, E. Whipple, and A. Korth. 1995. "HYDRA-A3-DIMENSIONAL ELECTRON AND ION HOT PLASMA INSTRUMENT FOR THE POLAR SPACECRAFT OF THE GGS MISSION." Space Science Reviews 71 (1-4): 459-495 [10.1007/bf00751338]

    Ogilvie, K. W., D. J. Chornay, R. J. Fritzenreiter, et al. F. Hunsaker, J. Keller, J. Lobell, G. Miller, J. D. Scudder, E. C. Sittler, R. B. Torbert, D. Bodet, G. Needell, A. J. Lazarus, J. T. Steinberg, and J. H. Tappan. 1995. "SWE, A COMPREHENSIVE PLASMA INSTRUMENT FOR THE WIND SPACECRAFT." Space Science Reviews 71 (1-4): 55-77 [10.1007/bf00751326]

    Ju, N. J., A. Bulgac, and J. W. Keller. 1994. "EXCITATION OF COLLECTIVE STATES IN FULLERENES." Computational Materials Science 2 (3-4): 615-627 [10.1016/0927-0256(94)90097-3]

    Ju, N. J., A. Bulgac, and J. W. Keller. 1993. "EXCITATION OF COLLECTIVE PLASMON STATES IN FULLERENES." Physical Review B 48 (12): 9071-9079 [10.1103/PhysRevB.48.9071]

    Keller, J. W., M. A. Coplan, and R. Goruganthu. 1992. "ELECTRON-ENERGY LOSS SPECTRA OF POLYCYCLIC AROMATIC-HYDROCARBONS." Astrophysical Journal 391 (2): 872-875 [10.1086/171396]

    Keller, J. W., and M. A. Coplan. 1992. "ELECTRON-ENERGY LOSS SPECTROSCOPY OF C-60." Chemical Physics Letters 193 (1-3): 89-92 [10.1016/0009-2614(92)85687-6]

    Keller, J. W., R. B. Torbert, and J. Vandiver. 1991. "HIGH-SPEED PITCH ANGLE SORTER." Review of Scientific Instruments 62 (5): 1353-1355 [10.1063/1.1142498]

    Keller, J. W., K. W. Ogilvie, J. W. Boring, and R. W. McKemie. 1991. "MEASUREMENT OF THE SECONDARY-EMISSION YIELD OF ELECTRONS FROM THIN CARBON FOILS AFTER PASSAGE OF LOW-ENERGY IONS." Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms 61 (3): 291-294 [10.1016/0168-583x(91)95632-n]

    Keller, J. W., W. T. Hill, D. L. Ederer, T. J. Gil, and P. W. Langhoff. 1987. "POLARIZED FLUORESCENCE SPECTROSCOPY OF O-2+." Journal of Chemical Physics 87 (6): 3299-3303 [10.1063/1.453023]

    Keller, J., R. Bonanno, M. X. Wang, M. S. Devries, and J. Weiner. 1986. "DETERMINATION OF INTERNAL ENERGY-DISTRIBUTION IN NA-2+ PRODUCED BY ASSOCIATIVE-IONIZATION COLLISIONS IN CROSSED BEAMS." Physical Review A 33 (3): 1612-1618 [10.1103/PhysRevA.33.1612]

    Keller, J., and J. Weiner. 1984. "PRODUCTION OF BA+ IN A 2-PHOTON RADIATIVE COLLISION IN CROSSED NA-BA BEAMS." Physical Review A 29 (4): 2230-2231 [10.1103/PhysRevA.29.2230]

    Keller, J., and J. Weiner. 1984. "MULTIPHOTON IONIZATION SPECTROSCOPY OF THE SODIUM DIMER." Physical Review A 30 (1): 213-219 [10.1103/PhysRevA.30.213]

    Keller, J., and J. Weiner. 1984. "DIRECT MEASUREMENT OF THE POTENTIAL-BARRIER HEIGHT IN THE B1-PI-MU-STATE OF THE SODIUM DIMER." Physical Review A 29 (5): 2943-2945 [10.1103/PhysRevA.29.2943]

    Keller, J., and J. Weiner. 1984. "DIRECT MEASUREMENT OF THE POTENTIAL BARRIER HEIGHT IN THE B1-PI-MU STATE OF SODIUM DIMER." Abstracts of Papers of the American Chemical Society 188 (AUG): 210-PHYS

    Non-Refereed

    Roark, J. H., J. W. Keller, F. Niepold, et al. S. E. Sakimoto, S. Stockman, and H. V. Frey. 2003. "3-Dimensional Topographic Models of Geologic Features for the Classroom." GSA Annual Meeting, Seattle WA., abstract 66476.

                                                                                                                                                                                            
    NASA Logo, National Aeronautics and Space Administration