نتایج جستجو برای: lunar cycle

تعداد نتایج: 280539  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2015
Jinhai Zhang Wei Yang Sen Hu Yangting Lin Guangyou Fang Chunlai Li Wenxi Peng Sanyuan Zhu Zhiping He Bin Zhou Hongyu Lin Jianfeng Yang Enhai Liu Yuchen Xu Jianyu Wang Zhenxing Yao Yongliao Zou Jun Yan Ziyuan Ouyang

We report the surface exploration by the lunar rover Yutu that landed on the young lava flow in the northeastern part of the Mare Imbrium, which is the largest basin on the nearside of the Moon and is filled with several basalt units estimated to date from 3.5 to 2.0 Ga. The onboard lunar penetrating radar conducted a 114-m-long profile, which measured a thickness of ∼5 m of the lunar regolith ...

2009
M. van Kan Parker C. B. Agee

Introduction: Modelling the dynamic evolution of the interior of the Moon is intrinsically linked to the density of lunar materials at high pressures and temperatures. Lunar magma density variations during crystallisation of the lunar magma ocean are particularly important, since the formation of plagioclase-rich highland rocks and mare basalts are related to density differences between lunar m...

2008
Yang Liu Jaesung Park Darren Schnare Eddy Hill Lawrence A. Taylor

The morphology shape and texture of dust fractions of five Apollo lunar soils and a lunar dust simulant, JSC-1Avf, was studied using scanning electron microscopy. Shape aspect ratio and complexity of particles was described based on the two-dimensional projection images. The distributions of aspect ratio and complexity of particles are reported. It was determined that the Apollo lunar dust part...

2012
Yang Liu Yunbin Guan Youxue Zhang George R. Rossman John M. Eiler Lawrence A. Taylor

Remote sensing discoveries of hydroxyl and water on the lunar surface have reshaped our view of the distribution of water and related compounds on airless bodies such as the Moon1–3. The origin of this surface water is unclear4, but it has been suggested that hydroxyl in the lunar regolith can result from the implantation of hydrogen ions by the solar wind1,5. Here we present Fourier transform ...

2010
T. W. Murphy E. G. Adelberger C. D. Hoyle C. W. Stubbs

Forty years ago, Apollo astronauts placed the first of several retroreflector arrays on the lunar surface. Their continued usefulness for laser ranging might suggest that the lunar environment does not damage optical devices. However, new laser ranging data reveal that the efficiency of the three Apollo reflector arrays is now diminished by a factor of 10 at all lunar phases and by an additiona...

Journal: :Science 1994
J O Dickey P L Bender J E Faller X X Newhall R L Ricklefs J G Ries P J Shelus C Veillet A L Whipple J R Wiant J G Williams C F Yoder

On 21 July 1969, during the first manned lunar mission, Apollo 11, the first retroreflector array was placed on the moon, enabling highly accurate measurements of the Earthmoon separation by means of laser ranging. Lunar laser ranging (LLR) turns the Earthmoon system into a laboratory for a broad range of investigations, including astronomy, lunar science, gravitational physics, geodesy, and ge...

2014
Jinsheng Cui Xuyan Hou Deming Zhao Yousong Hou Qiquan Quan Xiang Wu Zongquan Deng Shengyuan Jiang Dewei Tang

Drilling samples of lunar soil is an important and indispensable part of China’s lunar exploration project. The drill bit temperature during the drilling process is one of the key concerns for scholars, especially for the hard lunar rock drilling in vacuum. In this article, the simulation analysis of drilling in atmosphere and vacuum is conducted. Moreover, a fiber grating temperature measuring...

1999
C. C. Allen C. M. Weitz

Prospecting for Lunar Oxygen with Gamma-Ray Spectrometry and Multispectral Imaging C. C. Allen, C. M. Weitz, and D. S. McKay ...........................................................................19 Reliability of Calculating Average Soil Composition of Apollo Landing Sites A. Basu and S. Riegsecker ...............................................................................................

2018
Alexander J. Evans Sonia M. Tikoo Jeffrey C. Andrews-Hanna

Paleomagnetic analyses of lunar samples indicate that the Moon had a dynamo-generated magnetic field with ~50 μT surface field intensities between 3.85 and 3.56 Ga followed by a period of much lower (≤ ~5 μT) intensities that persisted beyond 2.5 Ga. However, we determine herein that there is insufficient energy associated with core convection—the process commonly recognized to generate long-li...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید