Entire Lunar Surface Research Articles

Creation of Digital Elevated Model using lunar images of Chandrayan – 1

The present work discusses the technique and methodology of analysing and Terrain Mapping Camera (TMC) Images acquired during India’s first Moon mission, Chandrayaan – 1, launched on October, 2008 for generating Digital Elevated Model (DEM). The Terrain Mapping Camera (TMC) on India’s first satellite for lunar exploration, Chandrayaan-1, is intended for systematic topographic mapping of the entire lunar surface, including the far side and the polar regions. A high resolution imagery of the entire Moon will help detailed study of specific lunar regions of scientific interests and further our understanding of lunar evolution. The swath of the instrument is 20 km. The digital elevation model (DEM) is a computer representation of the moon’s surface. DEMs can be generated by traditional photogrammetry based on aerial photos if they are available and they are created very often more economically by the means of space images. A Digital Terrain Model (DEM) is a continuous representation of a ground surface landform that is commonly used to produce topographic maps. DEMs are created by integrating data obtained from a wide range of techniques including remote sensing and land surveying.DEM's are sampled arrays of elevation values representing ground positions at regularly spaced intervals. Digital Elevation Model (DEM) is the terminology adopted by the USGS to describe terrain elevation data sets in a digital raster form. The normal orientation of data is by columns and rows. In this project work a DEM is created for each of the lunar images retrieved from the space craft using Triangulated Irregular Network (TIN) Key Words : Chandrayaan-1, DEM, Swath, TMC, TIN DOI: http://dx.doi.org/10.11591/ijece.v1i2.80

Lunette: A network of lunar landers for in-situ geophysical science

Over the last 3 years, a team at JPL has worked to design a new concept for a small, low cost lander applicable to a variety of in-situ lunar exploration activities. This concept, named Lunette, originated as a design which would exploit potential excess capacity of EELV launches by being compatible with the EELV Secondary Payload Adapter (ESPA). The original Lunette mission concept would have allowed up to six low cost landers to be delivered to a targeted region of the moon, with landings separated by a few km, allowing establishment of a regional network with a single, shared launch. The original concept faced limits in the extent of regional distribution of landing sites since all six landers were dependent on a single solid rocket braking motor. In the last year the Lunette team has focused on a modification of the original ESPA-based concept to a design that would allow launch of multiple individual landers (each with its own braking stage) on a single launch vehicle, where each lander would be capable of independent targeting and landing. With such an implementation, the entire lunar surface could be accessed for establishment of network nodes that could enable high priority geophysical measurements on a scale not seen since Apollo. The present paper discusses the current state of the design of the Lunette geophysical network lander, as well as describing mission design, science operations, and an innovative design solution allowing the lander to take critical data continuously, even over the lunar night, without the need for radioisotope power systems.

The lunar‐wide effects of basin ejecta distribution on the early megaregolith

Abstract— The lunar surface is marked by at least 43 large and ancient impact basins, each of which ejected a large amount of material that modified the areas surrounding each basin. We present an analysis of the effects of basin formation on the entire lunar surface using a previously defined basin ejecta model. Our modeling includes several simplifying assumptions in order to quantify two aspects of basin formation across the entire lunar surface: 1) the cumulative amount of material distributed across the surface, and 2) the depth to which that basin material created a well‐mixed megaregolith. We find that the asymmetric distribution of large basins across the Moon creates a considerable nearside‐farside dichotomy in both the cumulative amount of basin ejecta and the depth of the megaregolith. Basins significantly modified a large portion of the nearside while the farside experienced relatively small degrees of basin modification following the formation of the large South Pole‐Aitken basin. The regions of the Moon with differing degrees of modification by basins correspond to regions thought to contain geochemical signatures remnant of early lunar crustal processes, indicating that the degree of basin modification of the surface directly influenced the distribution of the geochemical terranes observed today. Additionally, the modification of the lunar surface by basins suggests that the provenance of lunar highland samples currently in research collections is not representative of the entire lunar crust. Identifying locations on the lunar surface with unique modification histories will aid in selecting locations for future sample collection.

Global lunar-surface mapping experiment using the Lunar Imager/Spectrometer on SELENE

Abstract The Moon is the nearest celestial body to the Earth. Understanding the Moon is the most important issue confronting geosciences and planetary sciences. Japan will launch the lunar polar orbiter SELENE (Kaguya) (Kato et al., 2007) in 2007 as the first mission of the Japanese long-term lunar exploration program and acquire data for scientific knowledge and possible utilization of the Moon. An optical sensing instrument called the Lunar Imager/Spectrometer (LISM) is loaded on SELENE. The LISM requirements for the SELENE project are intended to provide high-resolution digital imagery and spectroscopic data for the entire lunar surface, acquiring these data for scientific knowledge and possible utilization of the Moon. Actually, LISM was designed to include three specialized sub-instruments: a terrain camera (TC), a multi-band imager (MI), and a spectral profiler (SP). The TC is a high-resolution stereo camera with 10-m spatial resolution from a SELENE nominal altitude of 100 km and a stereo angle of 30° to provide stereo pairs from which digital terrain models (DTMs) with a height resolution of 20 m or better will be produced. The MI is a multi-spectral imager with four and five color bands with 20 m and 60 m spatial resolution in visible and near-infrared ranges, which will provide data to be used to distinguish the geological units in detail. The SP is a line spectral profiler with a 400-m-wide footprint and 300 spectral bands with 6–8 nm spectral resolution in the visible to near-infrared ranges. The SP data will be sufficiently powerful to identify the lunar surface’s mineral composition. Moreover, LISM will provide data with a spatial resolution, signal-to-noise ratio, and covered spectral range superior to that of past Earth-based and spacecraft-based observations. In addition to the hardware instrumentation, we have studied operation plans for global data acquisition within the limited total data volume allotment per day. Results show that the TC and MI can achieve global observations within the restrictions by sharing the TC and MI observation periods, adopting appropriate data compression, and executing necessary SELENE orbital plane change operations to ensure global coverage by MI. Pre-launch operation planning has resulted in possible global TC high-contrast imagery, TC stereoscopic imagery, and MI 9-band imagery in one nominal mission period. The SP will also acquire spectral line profiling data for nearly the entire lunar surface. The east-west interval of the SP strip data will be 3–4 km at the equator by the end of the mission and shorter at higher latitudes. We have proposed execution of SELENE roll cant operations three times during the nominal mission period to execute calibration site observations, and have reached agreement on this matter with the SELENE project. We present LISM global surface mapping experiments for instrumentation and operation plans. The ground processing systems and the data release plan for LISM data are discussed briefly.

The high precision gamma-ray spectrometer for lunar polar orbiter SELENE

The high precision gamma-ray spectrometer (GRS) is scheduled to be launched on the lunar polar orbiter of the SELENE mission in 2007. The GRS consists of a large Ge crystal as a main detector and massive bismuth germanate crystals as an anticoincidence detector. A Stirling cryocooler was adopted in cooling the Ge detector. The flight model of SELENE GRS has been completed and an energy resolution of 3.0 keV (FWHM) at 1.332 MeV has been achieved. The spectrometer aims to observe nuclear line gamma rays emitted from the lunar surface in a wide energy range from 100 keV to 12 MeV for one year and more to obtain chemical composition on the entire lunar surface. The gamma-ray data enable us to study lunar geoscience problems including crust and mantle composition, and volatile reservoirs at polar regions.

Gamma-ray detector on board lunar mission Chang’E-1

Gamma-ray spectrometer (GRS) is included in the payload of Chinese first lunar mission Chang’E-1 that will be launched in 2007. Specific objectives of the GRS are to map abundance of O, Si, Fe, Ti, U, Th, K, and perhaps, Mg, Al, and Ca to depths of about 20 cm. There are remarkable advantages for GRS application to remote sensing elemental materials over the entire lunar surface: large effective area and good ability for background rejection. We will describe the design of GRS and present its performance in this paper. Moreover, the GRS calibration will also be introduced.

Germanium detector with Stirling cryocooler for lunar gamma-ray spectroscopy

The gamma-ray spectrometer (GRS) of Japanese lunar polar orbiter SELENE uses a Ge detector for the first time on a lunar mission. This spectrometer will observe lunar gamma rays for 1 year or more to determine chemical composition over the entire lunar surface. For cooling the Ge detector, we adopted a Stirling cryocooler. The SELENE GRS flight model was completed and an energy resolution of 3.0 keV (FWHM) at 1.33 MeV was achieved. This paper describes the details of the detector-cryogenic system and its performance.

Thermal profiles of the eclipsed moon

The Midcourse Space Experiment (MSX) mapped the thermal 4.3 μm emission from the Moon during the eclipse of 27 September 1996 UT with a resolution of about 30″. MSX obtained ten 4.3 μm brightness temperature maps, one every 1 to 3 minutes, during the three twenty minute observations of the eclipse and was thus able to define spatially resolved (45km) cooling curves over the entire lunar surface. A large number of hot spots were observed that correlate well with those noted by previous observers. The hotspots tend to correspond to craters. Certain more extended regions, the maria and portions of maria, are warmer than the highlands. The 4.3 μm temperature contrasts observed at various regions of the eclipsed Moon by MSX also agree with the mid-infrared values previously published, although there is a tendency for the MSX values to be warmer. The MSX observations of the uneven cooling during the eclipse provide information on the thermo-physical properties of the various features.

Gamma-ray spectrometer for Japanese lunar polar orbiter

We review the current status of the development of Gamma-Ray Spectrometer (GRS) for the Lunar mission SELENE. The GRS instrument will measure gamma-rays in the energy range from 100 keV to 9 MeV. The instrument is a high-purity Ge detector surrounded by BGO and plastic scintillators which are operated as an anticoincidence shield, and is cooled by a Stirling cycle cryocooler. The primary objective is to provide global maps of the lunar composition. Measurements are anticipated for Fe, Ti, U, Th, K, Si, Mg, Al, O, Ca and Na over the entire lunar surface. The abundance of water ice in the permanently shaded craters at both the lunar poles will be measured with this instrument.

Radiative transfer in the surfaces of atmosphereless bodies. III - Interpretation of lunar photometry

view Abstract Citations (19) References (17) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Radiative transfer in the surfaces of atmosphereless bodies. III. Interpretation of lunar photometry. Lumme, K. ; Irvine, W. M. Abstract Narrowband and UBV photoelectric phase curves of the entire lunar disk and surface photometry of some craters have been interpreted using a newly developed generalized radiative transfer theory for planetary regoliths. The data are well fitted by the theory, yielding information on both macroscopic and microscopic lunar properties. Derived values for the integrated disk geometric albedo are considerably higher than quoted previously, because of the present inclusion of an accurately determined opposition effect. The mean surface roughness, defined as the ratio of the height to the radius of a typical irregularity, is found to be 0.9 + or - 0.1, or somewhat less than the mean value of 1.2 obtained for the asteroids. From the phase curves, wavelength-dependent values of the single scattering albedo and the Henyey-Greenstein asymmetry factor for the average surface particle are derived. Publication: The Astronomical Journal Pub Date: July 1982 DOI: 10.1086/113192 Bibcode: 1982AJ.....87.1076L Keywords: Astronomical Photometry; Lunar Craters; Lunar Surface; Radiative Transfer; Asteroids; Electrophotometry; Light Scattering; Lunar Albedo; Natural Satellites; Phase Shift; Regolith; Surface Properties; Surface Roughness; Ubv Spectra; Lunar and Planetary Exploration; Albedo:Moon; Moon:UBV Photometry; Moon Surface:Radiative Transfer full text sources ADS |

Lunar photoelectron layer

A layer of photoelectrons exists just above the sunlit lunar surface, owing to the solar photon flux. To aid physical understanding, two simple models of this layer are examined, and for these the net solar wind electron flux is neglected altogether. The general theory of a photoelectron layer (PEL) is developed and applied to obtain a third, reasonably accurate, model of the lunar PEL. The potential, electric field, and electron density are found as functions of height above the lunar surface for various positions on the sunlit hemisphere. This structure is obtained by using the best estimates available to date of the photoemissive properties of lunar soil. It is pointed out that there is a dense photoelectron ‘blanket’ confined to the first few centimeters above the moon's surface. The possibility of photoelectric ‘hot spots’ is discussed, as is also the possibility that the entire lunar surface may be photoelectrically hot. The consequences of the PEL are considered, namely, its role in the moon-solar wind interaction, in ion acceleration, and in surface dust transport. It is predicted that the NASA electric field detector would measure a field of about 6 v/m at its intended measuring height of 10 cm above the lunar surface and for all positions on the sunlit hemisphere from the subsolar point out to 60° from the moon-sun line.

Meteoritic material on the moon

Three types of meteoritic material are found on the Moon: micrometeorites, ancien planetesimal debris from the ‘early intense bombardment’, and debris of recent, crater-forming projectiles. Their amounts and compositions have been determined from trace element studies. The micrometeorite component is uniformly distributed over the entire lunar surface, but is seen most clearly in mare soils. It has a primitive, C1-chondrite-like composition, and comprises 1-1.5% of mature soils. Apparently it represents cometary debris. The mean annual influx rate is 2.4 × 10−9 g cm−2 yr−1. It shows no detectable time variation or dependence on selenographic position. The ancient component is seen in highland breccias and soils more than 3.9 AE old. It has a fractionated composition, with volatiles depleted relative to siderophiles. The abundance pattern does not match that of any known meteorite class. At least two varieties exist (LN and DN, with Ir/Au, Re/Au 0.25-0.5 and > 0.5 the C1 value). Both seem to represent the debris of planetesimals that produced the mare basins and highland craters during the first 700 Myr of the Moon's history. It appears that the LN and DN objects impacted at less then 10 km s−1, had diameters less than 100 km, contained more than 15% Fe, and were not internally differentiated. Both were depleted in volatiles; the LN objects also in refractories (Ir, Re). This makes it unlikely that the LN bodies served as important building blocks of the Moon. The crater-forming component has remained elusive. Only a possible hint of this component has been seen, in ejecta from Dune Crater and Apollo 12 KREEP glasses of Copernican (?) origin.

Inferences From the Optical Properties of the Moon Concerning the Nature and Evolution of the Lunar Surface

The unusual optical properties of the moon are summarized. They imply that the fine‐grained, compressible material observed by the Surveyor television cameras is representative of the entire lunar surface and very probably of the surfaces of Mercury, Mars, and the asteroids also. The soil is the result of repeated meteorite impacts and is not an ash flow. Evidence for darkening is examined, and it is concluded that a process is acting on the lunar surface to alter the albedo and color of the rock powder. Materials of chondritic or granitic composition are not prevalent on the moon. Differences in the optical properties of the maria and the highlands imply that the soil cover is thicker in the highlands than in the maria and that the high‐land soils are laterally more homogeneous than are those of the maria.

A discussion on infared astronomy - Mid-infrared spectroscopic observations of the Moon

Now that space probes have actually landed on the Moon, and man is soon to follow, one might suppose that the need for the development of lunar remote sensing techniques is past. Exactly the opposite is true. It must be remembered that no nation is financially able to support exploration of more than a very small percentage of the total surface area of the moon. Small areas immediately adjacent to a landing site will, of course, be explored in detail. Hopefully, there will be a few traverses made to discover the degree of lateral inhomogeneity of the surface materials. Realistically, however, we must plan on extending this ‘ground truth’ information to cover the entire lunar surface by remote means. In fact, remote sensing techniques will be employed prior to much of the detailed lunar surface exploration in order to define areas of maximum interest. The mid-infrared region of the spectrum is a wavelength region which possesses a high potential usefulness for remote sensing, because the molecular vibration spectra in this region are directly interpretable in terms of molecular composition. It is the purpose of this paper to examine this potential, review the theoretical justification for use of this wavelength region, describe laboratory studies of possible lunar surface materials, and present the data so far obtained from the moon itself.

Observational study of lunar visible emission

An observational program using the Mount Wilson 60-inch telescope and a grating spectrometer was conducted to study visible emission on the moon. During six lunations in 1965, 24 lunar positions were observed under a wide variety of lighting conditions. Observations and data reduction were performed according to the method of line depths using both the H (3968 A) and K (3934 A) Ca II Fraunhofer lines. No line depth changes were recorded, that indicated presence of radiation of nonsolar origin with an intensity greater than about 5% of reflected solar continuum; changes corresponding to greater than 2% nonsolar radiation were observed only infrequently. Statistically significant variations in the line depths were found, however, in the range 0.5 to 2.0% and varied both in lunar location and in time. Some anomalous ratios were recorded at single lunar areas during single observations. The correlation of the variations of the H line with the K line was found to differ with lunar area studied. It was concluded that the line depth changes were the result of visible emission occurring on or near the lunar surface. Several phenomena may be present. Some evidence exists for small and temporarily varying amounts of emission over the entire lunar surface.

High-Contrast Electronic Image-Orthicon Techniques Applied to the Lunar Surface.

The current interest in the structure and mapping of the lunar surface has led to the increased use of various methods of investigating the lunar surface, e.g., photographic stereoscopy over the entire range of lunar libration and the sequential photometry of lunar shadows, as presently employed by the Army and Air Force, respectively. The advent of high-contrast image-orthicon techniques appears to offer a valuable and versatile variation of the conventional point-by-point photometry of the lunar surface. By a combination of the subtraction of a constant bac~ground and the subsequent variable expansion of the residual range of brightness, it is possible to emphasize relatively minor differences in contrast, without the loss of gray-scaling, nearly simultaneously over the entire lunar surface. The effects of the inevitable increase in noise attendant in this technique can be effectively minimized by the use of long-persistence phosphors on the viewing screen and the use of relatively long exposures with the recording camera. The application of these techniques is at present a part of the image conversion program at the Dearborn Ubservatory. They are particularly adaptable to the detection of minor differences in lunar albedo and are capable of delineating fine differences particularly in the lunar maria, especially at full lunar phase, when lac~ of shadows limits the effectiveness of conventional photography. The method, therefore, offers more promise in the detection of differences in texture, and by inference, composition, of the lunar surface rather than in contour determination. Movies illustrating a run across the full moon at constant contrast, the effects of variation of contrast discrimination near the subsolar point, and preliminary studies of relative photometry of line elements using the video signal itself, have been made.