The Galileo mission to Jupiter revealed that Europa is an ocean world. The Galileo magnetometer experiment in particular provided strong evidence for a salty subsurface ocean beneath the ice shell, likely in contact with the rocky core. Within the ice shell and ocean, a number of tectonic and geodynamic processes may operate today or have operated at some point in the past, including solid ice convection, diapirism, subsumption, and interstitial lake formation.
View Article and Find Full Text PDFThe distribution of impact craters on the ejecta of Giordano Bruno, a recent (<10 Ma) 22-km diameter crater within the lunar highlands, exhibits substantial variations. We surveyed craters ≥ 10 m across a 1,323 km area of Giordano Bruno's ejecta and compared the distribution of craters with variations in thermophysical properties derived from the Lunar Reconnaissance Orbiter Diviner instrument. We used Diviner-derived rock abundance and nighttime regolith temperatures along with thermal model-predicted surface temperatures for a diversity of terrains to identify and isolate areas of the ejecta based on thermophysical properties such as bulk density and thermal conductivity.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2018
Water ice may be allowed to accumulate in permanently shaded regions on airless bodies in the inner solar system such as Mercury, the Moon, and Ceres [Watson K, et al. (1961) 66:3033-3045]. Unlike Mercury and Ceres, direct evidence for water ice exposed at the lunar surface has remained elusive.
View Article and Find Full Text PDFWe find that the reflectance of the lunar surface within 5 ° of latitude of the South Pole increases rapidly with decreasing temperature, near ~110K, behavior consistent with the presence of surface water iceThe North polar region does not show this behavior, nor do South polar surfaces at latitudes more than 5° from the pole. This South pole reflectance anomaly persists when analysis is limited to surfaces with slopes less than 10° to eliminate false detection due to the brightening effect of mass wasting, and also when the very bright south polar crater Shackleton is excluded from the analysis. We also find that south polar regions of permanent shadow that have been reported to be generally brighter at 1064 nm do not show anomalous reflectance when their annual maximum surface temperatures are too high to preserve water ice.
View Article and Find Full Text PDFCancer fatalism may impact outcomes, particularly for African American (AA) women with breast cancer (BrCa). We examined the psychometrics of the modified Powe Fatalism Inventory in sample of AA women with BrCa from two studies. Only the predetermination and God's will items satisfy the conditions to be classified as a strong subscale.
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