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1.
Understanding plume impingement by retrorockets on the surface of the Moon is paramount for safe lunar outpost design in NASA’s planned return to the Moon for the Constellation Program. Visual inspection, Scanning Electron Microscopy, and surface scanned topology have been used to investigate the damage to the Lunar Surveyor III spacecraft that was caused by the Apollo 12 Lunar Module’s close proximity landing. Two parts of the Surveyor III craft returned by the Apollo 12 astronauts, Coupons 2050 and 2051, which faced the Apollo 12 landing site, show that a fine layer of lunar regolith coated the materials and was subsequently removed by the Apollo 12 Lunar Module landing rocket. The coupons were also pitted by the impact of larger soil particles with an average of 103 pits/cm2. The average entry size of the pits was 83.7 μm (major diameter) × 74.5 μm (minor diameter) and the average estimated penetration depth was 88.4 μm. Pitting in the surface of the coupons correlates to removal of lunar fines and is likely a signature of lunar material imparting localized momentum/energy sufficient to cause cracking of the paint. Comparison with the lunar soil particle size distribution and the optical density of blowing soil during lunar landings indicates that the Surveyor III spacecraft was not exposed to the direct spray of the landing Lunar Module, but instead experienced only the fringes of the spray of soil. Had Surveyor III been exposed to the direct spray, the damage would have been orders of magnitude higher. 相似文献
2.
In 1970, the Soviet Lunokhod 1 rover delivered a French-built laser reflector to the Moon. Although a few range measurements were made within three months of its landing, these measurements—and any that may have followed—are unpublished and unavailable. The Lunokhod 1 reflector was, therefore, effectively lost until March of 2010 when images from the Lunar Reconnaissance Orbiter (LRO) provided a positive identification of the rover and determined its coordinates with uncertainties of about 100 m. This allowed the Apache Point Observatory Lunar Laser-ranging Operation (APOLLO) to quickly acquire a laser signal. The reflector appears to be in excellent condition, delivering a signal roughly four times stronger than its twin reflector on the Lunokhod 2 rover. The Lunokhod 1 reflector is especially valuable for science because it is closer to the Moon’s limb than any of the other reflectors and, unlike the Lunokhod 2 reflector, we find that it is usable during the lunar day. We report the selenographic position of the reflector to few-centimeter accuracy, comment on the health of the reflector, and illustrate the value of this reflector for achieving science goals. 相似文献
3.
J. W. Freeman Jr. H. K. Hills R. A. Lindeman R. R. Vondrak 《Earth, Moon, and Planets》1973,8(1-2):115-128
The Apollo 14 Suprathermal Ion Detector Experiment observed a series of bursts of 48.6 eV water vapor ions at the lunar surface during a 14-h period on March 7, 1971. The maximum flux observed was 108 ions cm–2 s–1 sr–1. These ions were also observed at Apollo 12, 183 km to the west. Evaluation of specific artificial sources including the Apollo missions and the Russian Lunokhod leads to the conclusion that the water vapor did not come from a man-made source. Natural sources exogenous to the Moon such as comets and the solar wind are also found to be inadequate to explain the observed fluxes. Consequently, these water vapor ions appear to be of lunar origin.Paper dedicated to Prof. Harold C. Urey on the occasion of his 80th birthday on 29 April 1973. 相似文献
4.
Brian J. O'Brien 《Planetary and Space Science》2011,59(14):1708-1726
This is the first review of 3 Apollo experiments, which made the only direct measurements of dust on the lunar surface: (i) minimalist matchbox-sized 270 g Dust Detector Experiments (DDEs) of Apollo 11, 12, 14 and 15, produced 30 million Lunar Day measurements 21 July 1969–30 September, 1977; (ii) Thermal Degradation Samples (TDS) of Apollo 14, sprinkled with dust, photographed, taken back to Earth into quarantine and lost; and (iii) the 7.5 kg Lunar Ejecta and Meteoroids (LEAM) experiment of Apollo 17, whose original tapes and plots are lost. LEAM, designed to measure rare impacts of cosmic dust, registered scores of events each lunation most frequently around sunrise and sunset. LEAM data are accepted as caused by heavily-charged particles of lunar dust at speeds of <100 m/s, stimulating theoretical models of transporting lunar dust and adding significant motivation for returning to the Moon. New analyses here show some raw data are sporadic bursts of 1, 2, 3 or more events within time bubbles smaller than 0.6 s, not predicted by theoretical dust models but consistent with noise bits caused by electromagnetic interference (EMI) from switching of large currents in the Apollo 17 Lunar Surface Experiment Package (ALSEP), as occurred in pre-flight LEAM-acceptance tests. On the Moon switching is most common around sunrise and sunset in a dozen heavy-duty heaters essential for operational survival during 350 h of lunar night temperatures of minus 170 °C. Another four otherwise unexplained features of LEAM data are consistent with the “noise bits” hypothesis. Discoveries with DDE and TDS reported in 1970 and 1971, though overlooked, and extensive DDE discoveries in 2009 revealed strengths of adhesive and cohesive forces of lunar dust. Rocket exhaust gases during Lunar Module (LM) ascent caused dust and debris to (i) contaminate instruments 17 m distant (Apollo 11) as expected, and (ii) unexpectedly cleanse Apollo hardware 130 m (Apollo 12) and 180 m (Apollo 14) from LM. TDS photos uniquely document in situ cohesion of dust particles and their adhesion to 12 different test surfaces. This review finds the entire TDS experiment was contaminated, being inside the aura of outgassing from astronaut Alan Shepard's spacesuit, and applies an unprecedented caveat to all TDS discoveries. Published and further analyses of Apollo DDE, TDS and LEAM measurements can provide evidence-based guidance to theoretical analyses and to management and mitigation of major problems from sticky dust, and thus help optimise future lunar and asteroid missions, manned and robotic. 相似文献
5.
The Lunar Laser Ranging experiment has been active since 1969 when Apollo astronauts placed the first retroreflector on the
Moon. The data accuracy of a few centimeters over recent decades, joined to a new numerically integrated ephemeris, DE421,
encourages a new analysis of the lunar physical librations of that ephemeris, and especially the detection of three modes
of free physical librations (longitude, latitude, and wobble modes). This analysis was performed by iterating a frequency
analysis and linear least-squares fit of the wide spectrum of DE421 lunar physical librations. From this analysis we identified
and estimated about 130–140 terms in the angular series of latitude librations and polar coordinates, and 89 terms in the
longitude angle. In this determination, we found the non-negligible amplitudes of the three modes of free physical libration.
The determined amplitudes reach 1.296′′ in longitude (after correction of two close forcing terms), 0.032′′ in latitude and
8.183′′ × 3.306′′ for the wobble, with the respective periods of 1056.13 days, 8822.88 days (referred to the moving node),
and 27257.27 days. The presence of such terms despite damping suggests the existence of some source of stimulation acting
in geologically recent times. 相似文献
6.
Physical conditions in the near-surface layer of the Moon are overviewed. This medium is formed in the course of the permanent micrometeoroid bombardment of the lunar regolith and due to the exposure of the regolith to solar radiation and high-energy charged particles of solar and galactic origin. During a considerable part of a lunar day (more than 20%), the Moon is passing through the Earth’s magnetosphere, where the conditions strongly differ from those in the interplanetary space. The external effects on the lunar regolith form the plasma-dusty medium above the lunar surface, the so-called lunar exosphere, whose characteristic altitude may reach several tens of kilometers. Observations of the near-surface dusty exosphere were carried out with the TV cameras onboard the landers Surveyor 5, 6, and 7 (1967–1968) and with the astrophotometer of Lunokhod-2 (1973). Their results showed that the near-surface layer glows above the sunlit surface of the Moon. This was interpreted as the scattering of solar light by dust particles. Direct detection of particles on the lunar surface was made by the Lunar Ejects and Meteorite (LEAM) instrument deployed by the Apollo 17 astronauts. Recently, the investigations of dust particles were performed by the Lunar Atmosphere and Dust Environment Explorer (LADEE) instrument at an altitude of several tens of kilometers. These observations urged forward the development of theoretical models for the lunar exosphere formation, and these models are being continuously improved. However, to date, many issues related to the dynamics of dust and the near-surface electric fields remain unresolved. Further investigations of the lunar exosphere are planned to be performed onboard the Russian landers Luna-Glob and Luna-Resurs. 相似文献
7.
C. C. Counselman III H. F. Hinteregger R. W. King I. I. Shapiro 《Earth, Moon, and Planets》1973,8(4):484-489
Differential very-long-baseline interferometric observations of signals from Apollo Lunar Surface Experiment Package telemetry transmitters will yield the relative projected positions of the transmitters with uncertainty of only 1-3 m, set mainly by uncertainty of the lunar ephemeris. Noise and systematic instrumental errors which in the past affected similar observations have been reduced to the equivalent of a few centimeters on the lunar surface by the development of a new type of differential receiver. Continued observations should yield a determination of the motion of the Moon about its center of mass with uncertainty less than 1 s of selenocentric arc. Improvements (by other means) in our knowledge of the Moon's orbital motion would allow a further order-of-magnitude refinement in the libration and relative position results obtainable by differential VLBI.Communication presented at the conference on Lunar Dynamics and Observational Coordinate Systems held January 15–17, 1973 at the Lunar Science Institute, Houston, Tex. U.S.A. 相似文献
8.
Information about the structure of lunar interior and evolution could be obtained from measurements of lunar free librations, gravitational field, dissipation etc.. In this paper the precision of determining free librations with Lunar Laser Ranging (LLR) data are estimated. Using the observing data from four telescopes for eighteen years the amplitudes and phases of free librations, the moments of inertia ratio of The Moon were determined. 相似文献
9.
A summary of total sulfur abundances representative of the Apollo Missions is presented. Lunar crystalline rocks range from
0 to 3100μg S g−1. Lunar soils range from 310 to 1300μg S g−1. Rock mixing models evaluate the distribution of sulfur and define indigenous rock components and extralunar contributions
of sulfur in lunar soils. Extralunar sulfur shows a positive correlation with a CC-1 like meteoritic component and solar wind
derived total carbon content in the Apollo 16 and 17 lunar soils.
Presented at the 25th International Geological Congress, Sydney, Australia, Section 15, Planetology.
Contribution No. 105 from the Center for Meteorite Studies. 相似文献
10.
The paper describes the lunar ephemeris EPM-ERA 2012. It is a part of the Ephemerides of Planets and the Moon (EPM) developed at the Institute of Applied Astronomy (IAA) of the Russian Academy of Sciences (RAS). In order to construct EPM-ERA 2012, 17580 lunar laser ranging (LLR) observations for 1970–2012 have been processed including 21 observations from the Lunokhod 1 reflector found by the Lunar Reconnaissance Orbiter (LRO) at the end of 2010. EPM-ERA 2012 is compared with American ephemerides DE403, DE405, DE421 ephemeris, and the French ephemeris INPOP10. The possibility of the use of the ephemeris EPM-ERA 2012 to address contemporary problems of ephemeris astronomy is considered. 相似文献
11.
月球激光测距 (LLR)代表了单光子探测技术的高峰 ,是国际激光测距界奋斗的目标。本文回顾了月球激光测距的现状以及它所特有的技术难度 ,同时介绍了我们为增加月球激光测距回波光子数所提出的一些可能的改进方法。特别介绍了在月球激光测距中利用月面反射器近旁的月面扩展源探测与计算大气倾斜量 ,进而对测月的激光束实施大气倾斜量实时改正这样一个全新的概念。最后介绍了云南天文台的激光测距系统以及它的近期工作目标。 相似文献
12.
Moonquakes and lunar tectonism 总被引：1，自引：0，他引：1
Gary Latham Maurice Ewing James Dorman David Lammlein Frank Press Naft Toksőz George Sutton Fred Duennebier Yosio Nakamura 《Earth, Moon, and Planets》1972,4(3-4):373-382
With the succesful installation of a geophysical station at Hadley Rille, on July 31, 1971, on the Apollo 15 mission, and the continued operation of stations 12 and 14 approximately 1100 km SW, the Apollo program for the first time achieved a network of seismic stations on the lunar surface. A network of at least three stations is essential for the location of natural events on the Moon. Thus, the establishment of this network was one of the most important milestones in the geophysical exploration of the Moon. The major discoveries that have resulted to date from the analysis of seismic data from this network can be summarized as follows:
- Lunar seismic signals differ greatly from typical terrestrial seismic signals. It now appears that this can be explained almost entirely by the presence of a thin dry, heterogeneous layer which blankets the Moon to a probable depth of few km with a maximum possible depth of about 20 km. Seismic waves are highly scattered in this zone. Seismic wave propagation within the lunar interior, below the scattering zone, is highly efficient. As a result, it is probable that meteoroid impact signals are being received from the entire lunar surface.
- The Moon possesses a crust and a mantle, at least in the region of the Apollo 12 and 14 stations. The thickness of the crust is between 55 and 70 km and may consist of two layers. The contrast in elastic properties of the rocks which comprise these major structural units is at least as great as that which exists between the crust and mantle of the earth. (See Toks?zet al., p. 490, for further discussion of seismic evidence of a lunar crust.)
- Natural lunar events detected by the Apollo seismic network are moonquakes and meteoroid impacts. The average rate of release of seismic energy from moonquakes is far below that of the Earth. Although present data do not permit a completely unambiguous interpretation, the best solution obtainable places the most active moonquake focus at a depth of 800 km; slightly deeper than any known earthquake. These moonquakes occur in monthly cycles; triggered by lunar tides. There are at least 10 zones within which the repeating moonquakes originate.
- In addition to the repeating moonquakes, moonquake ‘swarms’ have been discovered. During periods of swarm activity, events may occur as frequently as one event every two hours over intervals lasting several days. The source of these swarms is unknown at present. The occurrence of moonquake swarms also appears to be related to lunar tides; although, it is too soon to be certain of this point.
13.
Each year the Moon is bombarded by about 106 kg of interplanetary micrometeoroids of cometary and asteroidal origin. Most of these projectiles range from 10 nm to about 1 mm in size and impact the Moon at 10–72 km/s speed. They excavate lunar soil about 1000 times their own mass. These impacts leave a crater record on the surface from which the micrometeoroid size distribution has been deciphered. Much of the excavated mass returns to the lunar surface and blankets the lunar crust with a highly pulverized and “impact gardened” regolith of about 10 m thickness. Micron and sub-micron sized secondary particles that are ejected at speeds up to the escape speed of 2300 m/s form a perpetual dust cloud around the Moon and, upon re-impact, leave a record in the microcrater distribution. Such tenuous clouds have been observed by the Galileo spacecraft around all lunar-sized Galilean satellites at Jupiter. The highly sensitive Lunar Dust Experiment (LDEX) onboard the LADEE mission will shed new light on the lunar dust environment. LADEE is expected to be launched in early 2013.Another dust related phenomenon is the possible electrostatic mobilization of lunar dust. Images taken by the television cameras on Surveyors 5, 6, and 7 showed a distinct glow just above the lunar horizon referred to as horizon glow (HG). This light was interpreted to be forward-scattered sunlight from a cloud of dust particles above the surface near the terminator. A photometer onboard the Lunokhod-2 rover also reported excess brightness, most likely due to HG. From the lunar orbit during sunrise the Apollo astronauts reported bright streamers high above the lunar surface, which were interpreted as dust phenomena. The Lunar Ejecta and Meteorites (LEAM) Experiment was deployed on the lunar surface by the Apollo 17 astronauts in order to characterize the lunar dust environment. Instead of the expected low impact rate from interplanetary and interstellar dust, LEAM registered hundreds of signals associated with the passage of the terminator, which swamped any signature of primary impactors of interplanetary origin. It was suggested that the LEAM events are consistent with the sunrise/sunset-triggered levitation and transport of charged lunar dust particles. Currently no theoretical model explains the formation of a dust cloud above the lunar surface but recent laboratory experiments indicate that the interaction of dust on the lunar surface with solar UV and plasma is more complex than previously thought. 相似文献
14.
Mahesh Anand 《Earth, Moon, and Planets》2010,107(1):65-73
One of the most exciting recent developments in the field of lunar science has been the unambiguous detection of water (either
as OH or H2O) or water ice on the Moon through instruments flown on a number of orbiting spacecraft missions. At the same time, continued
laboratory-based investigations of returned lunar samples by Apollo missions using high-precision, low-detection, analytical
instruments have for the first time, provided the absolute abundance of water (present mostly as structurally bound OH− in mineral phases) in lunar samples. These new results suggest that the Moon is not an anhydrous body, questioning conventional
wisdom, and indicating the possibility of a wet lunar interior and the presence of distinct reservoirs of water on the lunar
surface. However, not all recent results point to a wet Moon and it appears that the distribution of water on the Moon may
be highly heterogeneous. Additionally, a number of sources are likely to have contributed to the water inventory of the Moon
ranging from primordial water to meteorite-derived water ice through to the water formed during the reaction of solar-wind
hydrogen with the lunar soil. Water on the Moon has implications for future astrobiological investigations as well as for
generating resources in situ during future exploration of the Moon and other airless bodies in the Solar System. 相似文献
15.
John A. Wood 《Icarus》1972
Lunar heat-flow calculations are carried out for a model Moon in which (a) near-surface initial temperatures are very high (as the occurence of a surface anorthositic layer seems to require), and (b) heat-generating radionuclides are transported upward when melting occurs. Near-surface regions are found to cool and then experience a resurgence of high temperature, as radionuclide-rich magmas from the lunar interior accumulate near the surface. This peaking of near-surface temperature can be brought into correspondence with the episode of vulcanism (∼ 3.5 × 109 years ago) that gave rise to the basalts represented in the Apollo samples, if we assume relatively high lunar temperatures in early times (due to high initial temperatures, or high content of radioactive elements, or both). 相似文献
16.
The importance of an accurate model of the Moon gravity field has been assessed for future navigation missions orbiting and/or
landing on the Moon, in order to use our natural satellite as an intermediate base for next solar system observations and
exploration as well as for lunar resources mapping and exploitation. One of the main scientific goals of MAGIA mission, whose
Phase A study has been recently funded by the Italian Space Agency (ASI), is the mapping of lunar gravitational anomalies,
and in particular those on the hidden side of the Moon, with an accuracy of 1 mGal RMS at lunar surface in the global solution
of the gravitational field up to degree and order 80. MAGIA gravimetric experiment is performed into two phases: the first
one, along which the main satellite shall perform remote sensing of the Moon surface, foresees the use of Precise Orbit Determination
(POD) data available from ground tracking of the main satellite for the determination of the long wavelength components of
gravitational field. Improvement in the accuracy of POD results are expected by the use of ISA, the Italian accelerometer
on board the main satellite. Additional gravitational data from recent missions, like Kaguya/Selene, could be used in order
to enhance the accuracy of such results. In the second phase the medium/short wavelength components of gravitational field
shall be obtained through a low-to-low (GRACE-like) Satellite-to-Satellite Tracking (SST) experiment. POD data shall be acquired
during the whole mission duration, while the SST data shall be available after the remote sensing phase, when the sub-satellite
shall be released from the main one and both satellites shall be left in a free-fall dynamics in the gravity field of the
Moon. SST range-rate data between the two satellites shall be measured through an inter-satellite link with accuracy compliant
with current state of art space qualified technology. SST processing and gravitational anomalies retrieval shall benefit from
a second ISA accelerometer on the sub-satellite in order to decouple lunar gravitational signal from other accelerations.
Experiment performance analysis shows that the stated scientific requirements can be achieved with a low mass and low cost
sub-satellite, with a SST gravimetric mission of just few months. 相似文献
17.
Dorothy S. Woolum D. S. Burnett Marian Furst J. R. Weiss 《Earth, Moon, and Planets》1975,12(2):231-250
Anin situ measurement of the lunar neutron density from 20 to 400 g cm?2 depth below the lunar surface was made by the Apollo 17 Lunar Neutron Probe Experiment (LNPE) using particle tracks produced by the10B (n,α)7Li reaction. Both the absolute magnitude and the depth profile of the neutron density are in good agreement with theoretical calculations by Lingenfelter, Canfield, and Hampel. However, relatively small deviations between experiment and theory in the effect of Cd absorption on the neutron density and in the relative149Sm to157Gd capture rates reported previously (Russet al., 1972) imply that the true lunar157Gd capture rate is about one half of that calculated theoretically. 相似文献
18.
Giorgio Perrotta M. Stipa D. Silvi S. Coltellacci G. Curti G. Colonna T. Formica V. Casali T. Fossati F. Di Matteo M. Zelli M. Rinaldi L. Ansalone A. Di Salvo 《Experimental Astronomy》2011,32(1):63-82
The Mission MAGIA (Missione Altimetrica Geofisica GeochImica lunAre) was proposed in the framework of the ??Bando per Piccole Missioni?? of ASI (Italian Space Agency) in 2007. The mission was selected for a phase A study by ASI on February 7th 2008. The tight budget allocation, combined with quite ambitious scientific objectives, set challenging requirements for the satellite design. The paper gives a fast overview of the payloads complement and of the mission-constrained design drivers, including cost minimization, risk reduction, and AIT flexibility. The spacecraft architecture is then outlined, along with an overview of the key subsystems and trade-offs. Some details are given of a Moon gravitometric experiment based on a mother?Cdaughter satellite configuration with the daughter being a subsatellite released from the MAGIA satellite and intended to circle the Moon at a very low altitude. Budgets are appended at the end of the paper showing the key study results. 相似文献
19.
J. Zussman 《Earth, Moon, and Planets》1972,5(3-4):422-435
Crystallization from the molten state has been an important process for the formation of rocks on the Moon; the phenomenon of fractional crystallization is therefore discussed. The principal chemical and mineralogical features of the Apollo 11, 12 and 14 basaltic crystalline rocks are described, and an account is given of other rock types and minerals which are represented among the coarser particles in the lunar soils. A comparison is made between the chemical compositions (major, minor and trace element concentrations) of rocks and soils.Based upon the above data, one possible model for the outer shell of the Moon is presented, which consists of an outer layer of Al-rich rocks underlain by a layer which is more ferromagnesian in character. Partial melting of the latter was probably responsible for the extrusion of lavas at the surface which spread to form the basalts (Apollo 11 and 12) of the non-circular maria. The Apollo 14 (Fra Mauro) basalts are relatively enriched in potassium, rare earth elements, zirconium, phosphorus and certain other elements and may derive from partial melting of the more aluminous upper layer.The separation of the outer Moon into two layers could have occurred through gravity-aided fractional crystallization at an early stage (first few hundred m yr) in lunar history.Paper presented to the NATO Advanced Study Institute on Lunar Studies, Patras, Greece, September 1971. 相似文献
20.
Yosio Nakamura James Dorman Frederick Duennebier David Lammlein Gary Latham 《Earth, Moon, and Planets》1975,13(1-3):57-66
Data relevant to the shallow structure of the Moon obtained at the Apollo seismic stations are compared with previously published results of the active seismic experiments. It is concluded that the lunar surface is covered by a layer of low seismic velocity (V p ? 100 m s?1), which appears to be equivalent to the lunar regolith defined previously by geological observations. This layer is underlain by a zone of distinctly higher seismic velocity at all of the Apollo landing sites. The regolith thicknesses at the Apollo 11, 12, and 15 sites are estimated from the shear-wave resonance to be 4.4, 3.7, and 4.4 m, respectively. These thicknesses and those determined at the other Apollo sites by the active seismic experiments appear to be correlated with the age determinations and the abundances of extralunar components at the sites. 相似文献