نتایج جستجو برای: 1260 lunar years
تعداد نتایج: 998433 فیلتر نتایج به سال:
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 ...
Introduction: Water ice and ilmenite both have unique dielectric responses that can be used to detect their concentration as a function of depth, noninvasively from the lunar surface. Electrical measurements at the surface can also be used to determine the density of the lunar regolith. Subsurface water ice may exist in permanently shadowed regions near the poles of the Moon [1-6]. The presence...
Since entering lunar orbit on June 23, 2009 the Lunar Reconnaissance Orbiter (LRO) has made comprehensive measurements of the Moon and its environment. The seven LRO instruments use a variety of primarily remote sensing techniques to obtain a unique set of observations. These measurements provide new information regarding the physical properties of the lunar surface, the lunar environment, and ...
We determined model ages of mare deposits on the farside of the Moon on the basis of the crater frequency distributions in 10-meter-resolution images obtained by the Terrain Camera on SELENE (Selenological and Engineering Explorer) (Kaguya). Most mare volcanism that formed mare deposits on the lunar farside ceased at approximately 3.0 billion years ago, suggesting that mare volcanism on the Moo...
Recent genomic surveys have produced high-resolution haplotype information, but only in a small number of human populations. We report haplotype structure across 12 Mb of DNA sequence in 927 individuals representing 52 populations. The geographic distribution of haplotypes reflects human history, with a loss of haplotype diversity as distance increases from Africa. Although the extent of linkag...
Starch consumption is a prominent characteristic of agricultural societies and hunter-gatherers in arid environments. In contrast, rainforest and circum-arctic huntergatherers and some pastoralists consume much less starch1–3. This behavioral variation raises the possibility that different selective pressures have acted on amylase, the enzyme responsible for starch hydrolysis4. We found that co...
Figure 1: Location of lunar landing sites and the Apollo passive seismometer network. INTRODUCTION Geophysical observations of the Moon via a global and long-lived network of stations will yield a wealth of knowledge from regions heretofore inaccessible using the Apollo database. Data collected over a period of at least 6 years (covering one lunar tidal cycle) will yield information on the natu...
To procure the status of groundwater level fluctuations in arid and semi-arid areas, it is necessary to obtain accurate forecast of fluctuations data. Time series as a linear model have been utilized to generate synthetic data and predict future groundwater level. Minitab17 software and monthly depth of groundwater level data of 20 years (1991-2011) for 25 piezometric wells of plain were used. ...
BACKGROUND In high human immunodeficiency virus (HIV) prevalence population, tuberculosis (TB) is the leading cause of morbidity and mortality. HIV is driving the TB epidemic in many countries, especially those in sub-Saharan Africa. We assessed the survival time and predictors of mortality among tuberculosis patients under directly observed treatment, short course (DOTS) strategy in Dessie Ref...
Remote sensing indicates the presence of hydrogen rich regions associated with the lunar poles. The logical hypothesis is that there is cryogenically trapped water ice located in craters at the lunar poles. Some of the craters have been in permanent darkness for a billion years. The presence of water at the poles as well as other scientific advantages of a polar base, have influenced NASA plans...
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