Linked Life Data

18554085

Source:http://linkedlifedata.com/resource/pubmed/id/18554085

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2008-8-5
pubmed:abstractText
The ability to locate and characterize icy deposits and other hydrogenous materials on the Moon and Mars will help us understand the distribution of water and, therefore, possible habitats at Mars, and may help us locate primitive prebiotic compounds at the Moon's poles. We have developed a rover-borne neutron probe that localizes a near-surface icy deposit and provides information about its burial depth and abundance. We have also developed a borehole neutron probe to determine the stratigraphy of hydrogenous subsurface layers while operating within a drill string segment. In our field tests, we have used a neutron source to "illuminate" surrounding materials and gauge the instruments' efficacy, and we can simulate accurately the observed instrument responses using a Monte Carlo nuclear transport code (MCNPX). An active neutron source would not be needed for lunar or martian near-surface exploration: cosmic-ray interactions provide sufficient neutron flux to depths of several meters and yield better depth and abundance sensitivity than an active source. However, for deep drilling (>or=10 m depth), a source is required. We also present initial tests of a borehole gamma ray lithodensity tool and demonstrate its utility in determining soil or rock densities and composition.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1557-8070
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
639-52
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Surface and downhole prospecting tools for planetary exploration: tests of neutron and gamma ray probes.
pubmed:affiliation
Planetary Systems Branch, Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, California 94035-1000, USA. richard.c.elphic@nasa.gov
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't