1,721,318 research outputs found
Geology, life and habitability
No full textThe examination of contemporary systems and the rock record has demonstrated that the biosphere and geosphere are intimately linked, presumably since life's origin. The geosphere provides trace and essential nutrients for life, sources of reduced compounds and electron acceptors, that is, the energy for life to occur, and habitats ranging from ‘simple’ surfaces to grow on to unique endolithic environments formed at least in part by the microorganisms themselves. The hydrosphere is perhaps more important than the lithosphere, because it provides the solvent necessary for biogeochemical reactions and life to occur. The major question about how life originated cannot be readily answered; however, the question of habitability is relatively easy. Using Earth as our role model, there are several candidate extrasolar bodies within our solar system, for example, Mars and Europa, that could support life
The BELA - The first European Planetary Laser Altimeter: Conceptual Design and Technical Status
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Development of the BepiColombo Laser Altimeter BELA
No full textThe BepiColombo Laser Altimeter (BELA) is the first European Laser Altimeter for planetary exploration which has been selected by ESA for flight aboard of ESA's BepiColombo mission to planet Mercury. A consortium led by the Physikalisches Institut Bern and Institute for Planetary Research at the German Aerospace Center (DLR) will develop a laser altimeter based on the classical principle of laser pulse time of flight measurement. The instrument is based on a longitudinally pumped Nd:YAG laser with 50mJ pulse energy and pulses of about 3 ns pulse duration, operating nominally at 10 Hz repetition rate. BELA performs global topographic mapping with high accuracy of 1m and a surface shot to shot spacing in the range of 300m. Laser Ranging will be done at a distance up to 1000 km with a detection probability >70%. The ground footprint of the laser beam amounts to about 100m
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