Jay R Johnson

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[1] The Panoramic Camera (Pancam) investigation is part of the Athena science payload launched to Mars in 2003 on NASA’s twin Mars Exploration Rover (MER) missions. The scientific goals of the Pancam investigation are to assess the high-resolution morphology, topography, and geologic context of each MER landing site, to obtain color images to constrain the(More)
R. E. Arvidson, S. W. Ruff, R. V. Morris, D. W. Ming, L. S. Crumpler, A. S. Yen, S. W. Squyres, R. J. Sullivan, J. F. Bell III, N. A. Cabrol, B. C. Clark, W. H. Farrand, R. Gellert, R. Greenberger, J. A. Grant, E. A. Guinness, K. E. Herkenhoff, J. A. Hurowitz, J. R. Johnson, G. Klingelhöfer, K. W. Lewis, R. Li, T. J. McCoy, J. Moersch, H. Y. McSween, S. L.(More)
H. Y. McSween, M. B Wyatt, R. Gellert, J. F. Bell III, R. V. Morris, K. E. Herkenhoff, L. S. Crumpler, K. A. Milam, K. R. Stockstill, L. L. Tornabene, R. E. Arvidson, P. Bartlett, D. Blaney, N. A. Cabrol, P. R. Christensen, B. C. Clark, J. A. Crisp, D. J. Des Marais, T. Economou, J. D. Farmer, W. Farrand, A. Ghosh, M. Golombek, S. Gorevan, R. Greeley, V. E.(More)
[1] The !5 km of traverses and observations completed by the Opportunity rover from Endurance crater to the Fruitbasket outcrop show that the Meridiani plains consist of sulfate-rich sedimentary rocks that are largely covered by poorly-sorted basaltic aeolian sands and a lag of granule-sized hematitic concretions. Orbital reflectance spectra obtained by(More)
[1] The Mars Exploration Rover (MER) Spirit excavated sulfur-rich soils exhibiting high albedo and relatively white to yellow colors at three main locations on and south of Husband Hill in Gusev crater, Mars. The multispectral visible/near-infrared properties of these disturbed soils revealed by the Pancam stereo color camera vary appreciably over small(More)
Recalibrated and geometrically registered multispectral images from the Imager for Mars Pathfinder (IMP) were analyzed using Spectral Mixture Analysis (SMA) and related techniques. SMA models a multispectral image scene as a linear combination of endmember spectra, and anomalous materials which do not fit the model are detected as model residuals. While(More)
OBJECTIVE To examine the influence of solar cycle and geomagnetic effects on the incidence of giant cell arteritis (GCA) and rheumatoid arthritis (RA). METHODS We used data from patients with GCA (1950-2004) and RA (1955-2007) obtained from population-based cohorts. Yearly trends in age-adjusted and sex-adjusted incidence were correlated with the F10.7(More)
[1] Reduced weathering rates due to the lack of liquid water and significantly greater typical surface ages should result in a higher density of meteorites on the surface of Mars compared to Earth. Several meteorites were identified among the rocks investigated during Opportunity’s traverse across the sandy Meridiani plains. Heat Shield Rock is a IAB iron(More)