نتایج جستجو برای: lunar months

تعداد نتایج: 341049  

2003
Noah E. PETRO Carlé M. PIETERS

available online at http://meteoritics.org The lunar-wide effects of basin ejecta distribution on the early megaregolith Noah E. PETRO1, 2* and Carlé M. PIETERS1 1Department of Geological Sciences, Brown University, Box 1846, Providence, Rhode Island, 02912, USA 2Now at: Planetary Geodynamics Laboratory, Code 698, NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771, USA *Corresponding ...

2009
T. J. Stubbs D. A. Glenar D. T. Richard

Introduction: When viewing the lunar exosphere there appear to be three major sources of optical scattering that are typically observed: atomic line emissions from the exospheric gases [1]; the relatively bright coronal and zodiacal light (CZL) background [2]; and the putative scattering of sunlight by exospheric dust, which is also referred to as “lunar horizon glow” (LHG) [3]. The lunar exosp...

2003
C. R. Neal D. J. Lawrence

Introduction: The New Views of the Moon initiative has integrated remotely sensed and sample data in its approach to synthesizing lunar research over the last 30+ years. This integration has clearly demonstrated what we know and, maybe more importantly, what we don t know about the Moon. Most significantly, it has helped to formulate fundamental scientific questions about the Moon that still ne...

2010
Laurence Nyquist Chi-Yu Shih Donald Bogard Akira Yamaguchi

Anorthosites occur ubiquitously within the lunar crust at depths of 3-30 km in apparent confirmation of the Lunar Magma Ocean (LMO) hypothesis [1,5]. We will present recent chronological studies of anorthosites [2] that are relevant both to the LMO hypothesis and also to the lunar cataclysm hypothesis. Old (ca. 4.4 Ga) Sm-Nd ages have been determined for some Apollo 16 anorthosites, and primiti...

2009
B. T. Greenhagen

Introduction: The Diviner Lunar Radiometer Compositional Investigation will use multichannel (0.3 – 300 μm) spectral observations to constrain the composition of the lunar surface. Diviner will be the first lunar orbiting instrument capable of identifying the Christiansen feature (mid-infrared emissivity maximum), which is a good compositional identifier [1]. Diviner will also be the first inst...

2012
A. Morbidelli S. Marchi W. F. Bottke D. A. Kring

We revisit the early evolution of the Moon’s bombardment. Our work combines modeling (based on plausible projectile sources and their dynamical decay rates) with constraints from the lunar crater record, radiometric ages of the youngest lunar basins, and the abundance of highly siderophile elements in the lunar crust and mantle. We deduce that the evolution of the impact flux did not narrow imp...

2006
J. N. Head

Introduction: In the context of resumed lunar exploration , the existence of water ice at the lunar poles has become a pressing question. In support of human return to the moon, the confirmation of the water ice signature detected from orbiting spacecraft [1,2] is a high-priority task that can only be accomplished in situ. Therefore, a landed mission to the permanently shadowed lunar polar crat...

2009
J. Guo C. Han AAS

Future lunar missions ask for the capability to perform precise Guidance, Navigation and Control (GNC) to the selected landing sites on the lunar surface. This paper studies the guidance issues for the lunar pinpoint soft landing problem. The primary contribution of this paper is the design of descent guidance law based on the Pontryagin maximum principle. The simulation shows that the proposed...

2008
Norbert I. Kömle Jerzy Grygorczuk

The upcoming lunar lander missions, for example Chang’e 2 from CNSA and several mission proposals and studies currently under consideration at NASA (e.g. Neal et al., ROSES 2006 Proposal to NASA, 2006), ESA (e.g. Hufenbach, European Workshop on Lunar Landers, ESTEC, Noordwijk, The Netherlands, 2005; Foing, EPSC Abstracts, vol 2, EPSC2007-A-00422, European Planetary Science Congress, Potsdam, Ge...

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