SEARCH · USGS Science

Results for “The Moon”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

USGS2023

Relationship between explosive and effusive volcanism in the Montes Apenninus region of the Moon

Lunar Pyroclastic Deposits (LPDs) are sites of explosive volcanism and often occur in areas of effusive volcanism on the Moon. On Earth, it has been observed that most volcanism has both effusive and explosive phases, whereas on the Moon, these two types of volcanism have typically been considered separately. We hypothesize that the relationship between explosive and effusive volcanism on the Moon is similar to what is observed on the Earth, where individual eruptions can experience multiple phases rather than one type of volcanism always preceding another or occurring separately. We present observations from the Moon Mineralogy Mapper detailing compositional relationships between volcanic features in the lunar Montes Apenninus region. We evaluated whether co-located LPDs and effusive features (e.g., rilles, mare) could have erupted from the same volcanic vent or even at the same time based on their compositional similarities and stratigraphic relationships. We found that the LPDs have varied stratigraphic relationships with co-located effusive features. We identified LPDs near sinuous rilles that may be related to the formation of the rille, where explosive and effusive volcanism occurred at the same vent (e.g., Mozart Rille), and LPDs that may be unrelated to the rille (e.g., Rimae Bode and Rima Bode LPD). Our results suggest that lunar volcanism can mirror terrestrial volcanism, with explosive and effusive eruptions demonstrating more complex dynamics and relationships than previously thought. This variability suggests that the relationship between LPDs and nearby volcanic features cannot be generalized for studies on their resource potential, eruption styles, or deposit volume.

Journal of Geophysical Research: Planets↗

USGS2009

Character and spatial distribution of OH/H 2 O on the surface of the moon seen by M 3 on chandrayaan-1

The search for water on the surface of the anhydrous Moon had remained an unfulfilled quest for 40 years. However, the Moon Mineralogy Mapper (M 3 ) on Chandrayaan-1 has recently detected absorption features near 2.8 to 3.0 micrometers on the surface of the Moon. For silicate bodies, such features are typically attributed to hydroxyl- and/or water-bearing materials. On the Moon, the feature is seen as a widely distributed absorption that appears strongest at cooler high latitudes and at several fresh feldspathic craters. The general lack of correlation of this feature in sunlit M 3 data with neutron spectrometer hydrogen abundance data suggests that the formation and retention of hydroxyl and water are ongoing surficial processes. Hydroxyl/water production processes may feed polar cold traps and make the lunar regolith a candidate source of volatiles for human exploration.

Science↗

USGS1996

Establishing the moon as a spectral radiance standard

A new automated observatory dedicated to the radiometry of the moon has been constructed to provide new radiance information for calibration of earth-orbiting imaging instruments, particularly Earth Observing System instruments. Instrumentation includes an imaging photometer with 4.5-in. resolution on a fully digital mount and a full-aperture radiance calibration source. Interference filters within 0.35–0.95 µm correspond to standard stellar magnitude systems, accommodate wavelengths of lunar spectral contrast, and approximate some band-passes of planned earth-orbiting instruments (ASTER, Landsat-7 ETM, MISR, MODIS, and SeaWIFS). The same equipment is used for lunar and stellar observations, with the use of an aperture stop in lunar imaging to comply with Nyquist's theorem and lengthen exposure times to avoid scintillation effects. A typical robotic night run involves observation of about 60 photometric standard stars and the moon; about 10 of the standard stars are observed repeatedly to determine atmospheric extinction, and the moon is observed several times. Observations are to be made on every photometric night during the bright half of the month for at least 4.5 years to adequately cover phase and libration variation. Each lunar image is reduced to absolute exoatmospheric radiance and reprojected to a fixed selenographic grid system. The collection of these images at various liberators and phase angles will be reduced to photometric models for each of the approximately 120 000 points in the lunar grid for each filter. Radiance models of the moon can then be produced for the precise geometry of an orbiting instrument observation. Expected errors are under 1% relative and 2.5% absolute. A second telescope operating from 1.0 to 2.5 µm is planned.

Journal of Atmospheric and Oceanic Technology↗

USGS2020

The Moon as a climate-quality radiometric calibration reference

On-orbit calibration requirements for a space-based climate observing system include long-term sensor response stability and reliable inter-calibration of multiple sensors, both contemporaneous and in succession. The difficulties with achieving these for reflected solar wavelength instruments are well known. The Moon can be considered a diffuse reflector of sunlight, and its exceptional photometric stability has enabled development of a lunar radiometric reference, manifest as a model that is queried for the specific conditions of Moon observations. The lunar irradiance model developed by the Robotic Lunar Observatory (ROLO) project has adequate precision for sensor response temporal trending, but a climate-quality lunar reference will require at least an order of magnitude improvement in absolute accuracy. To redevelop the lunar calibration reference with sub-percent uncertainty and SI traceability requires collecting new, high-accuracy Moon characterization measurements. This paper describes specifications for such measurements, along with a conceptual framework for reconstructing the lunar reference using them. Three currently active NASA-sponsored projects have objectives to acquire measurements that can support a climate-quality lunar reference: air-LUSI, dedicated lunar spectral irradiance measurements from the NASA ER-2 high altitude aircraft; ARCSTONE, dedicated lunar spectral reflectance measurements from a small satellite; and Moon viewing opportunities by CLARREO Pathfinder from the International Space Station.

Remote Sensing↗

USGS2011

Compositional diversity and geologic insights of the Aristarchus crater from Moon Mineralogy Mapper data

The Moon Mineralogy Mapper (M3) acquired high spatial and spectral resolution data of the Aristarchus Plateau with 140 m/pixel in 85 spectral bands from 0.43 to 3.0 m. The data were collected as radiance and converted to reflectance using the observational constraints and a solar spectrum scaled to the Moon-Sun distance. Summary spectral parameters for the area of mafic silicate 1 and 2 m bands were calculated from the M3 data and used to map the distribution of key units that were then analyzed in detail with the spectral data. This analysis focuses on five key compositional units in the region. (1) The central peaks are shown to be strongly enriched in feldspar and are likely from the upper plagioclase-rich crust of the Moon. (2) The impact melt is compositionally diverse with clear signatures of feldspathic crust, olivine, and glass. (3) The crater walls and ejecta show a high degree of spatial heterogeneity and evidence for massive breccia blocks. (4) Olivine, strongly concentrated on the rim, wall, and exterior of the southeastern quadrant of the crater, is commonly associated the impact melt. (5) There are at least two types of glass deposits observed: pyroclastic glass and impact glass. Copyright 2011 by the American Geophysical Union.

Journal of Geophysical Research E: Planets↗

USGS2012

Compositional variations on the Moon: Recalibration of Galileo solid‐state imaging data for the Orientale region and farside

Updated radiometric calibration and systematic processing procedures for Galileo solid‐state imaging (SSI) data from the first (1990) Earth‐Moon encounter are presented. These procedures were applied to a whole‐disk imaging sequence of the Moon centered near Mare Orientale, called Lunmap 14 (L14). Processing of L14 data included radiometric calibration, subpixel coregistration, scattered light removal, geometric control and reprojection, photometric normalization, and calibration to Earth‐based spectra. Coregistration and scattered‐light removal procedures are improvements over the initial calibration of the SSI mosaics. The effects of scattered light correction are best seen using a whole‐Moon view such as L14; resolution of the debated amounts of light scattering from within or outside the camera field of view is not necessary. Scattered light removal particularly affects the 1‐μm spectral region and has implications for interpretation of mafic mineral signatures in mare deposits of the lunar limb and farside. Recalibrated spectra indicate that mare ponds of the limb show moderately deep 1‐μm absorptions, and thus mafic mineral contents, comparable to those of other nearside basalts. Mafic mineral contents of Schiller‐Shickard cryptomaria are higher than previously thought and are similar to some low‐Ti nearside basalts. Many of the recalibrated spectra from South Pole/Aitken are similar to those of Schiller‐Schickard cryptomaria, suggesting that many of these soils represent a mixed mare/highland lithology. The hypothesis that there is an olivine enrichment in southern South Pole/Aitken basin is not supported strongly by spectra shown here.

Journal of Geophysical Research: Planets↗

USGS2012

The competition between thermal contraction and differentiation in the stress history of the Moon

The scarcity of both extension and compression features on the Moon strongly constrains the history of the lunar radius—to variations of less than ±1 km over the past 3.8 Gyr. This limit has traditionally been interpreted as requiring a delicate balance between thermal contraction of the near‐surface and expansion of a substantial cold interior region. Recent theories of lunar origin (e.g., giant impact), in contrast, favor a “hot” initial state. We propose that a reconciliation may be possible by taking account of the volume change Δ V / V | d due to differentiation. We calculate STP densities based on simplified normative mineralogies for a suite of estimates of the bulk lunar composition, of primary lunar basalt, and of the residuum left when the maximum amount of the latter is extracted from the former. Typically Δ V / V | d ≃ 2 to 5%—an expansion equivalent to heating by ∼10 3 K. Provided the timing of differentiation is correct, one might offset the cooling of a magma ocean as much as 630 km deep by differentiation of the remainder of the Moon (which need not start much below the solidus temperature). A large but not impossible amount of gabbroic melt production is implied: ∼100 times the volume of mare basalts known to have been extruded. We do not address the detailed genetic relationship of this melt to the basalts observed on the lunar surface but point out that it need not have reached the surface directly or even have entered the crust in order for the expansion to have occurred. To assess the timing of melt formation, we investigate a simple conductive lunar thermal model which takes account of both Δ V / V | d and thermal contraction. Our initial state is characterized by a central temperature T c and a depth Z 0 above which the material (derived from the magma ocean) is already at the solidus and is not suceptible to volume changes upon further differentiation. We find a range of models satisfying the limits on radius increase and decrease. The hottest has T c = 1210 K, Z 0 = 400 km; without Δ V / V | d , we would need a larger or colder (or both) core, e.g., T c ≲ 700 K for Z 0 = 200–400 km, in agreement with previous investigators. Our modeling thus lends credence to the idea that the Moon could have been initially ≳50% molten (with the remainder relatively close to the solidus) and yet experienced little volume change over the last 3.8 Gyr.

Journal of Geophysical Research B: Solid Earth↗

USGS2023

Moon-forming impactor as a source of Earth’s basal mantle anomalies

Seismic images of Earth’s interior have revealed two continent-sized anomalies with low seismic velocities, known as the large low-velocity provinces (LLVPs), in the lowermost mantle . The LLVPs are often interpreted as intrinsically dense heterogeneities that are compositionally distinct from the surrounding mantle . Here we show that LLVPs may represent buried relics of Theia mantle material (TMM) that was preserved in proto-Earth’s mantle after the Moon-forming giant impact . Our canonical giant-impact simulations show that a fraction of Theia’s mantle could have been delivered to proto-Earth’s solid lower mantle. We find that TMM is intrinsically 2.0–3.5% denser than proto-Earth’s mantle based on models of Theia’s mantle and the observed higher FeO content of the Moon. Our mantle convection models show that dense TMM blobs with a size of tens of kilometres after the impact can later sink and accumulate into LLVP-like thermochemical piles atop Earth’s core and survive to the present day. The LLVPs may, thus, be a natural consequence of the Moon-forming giant impact. Because giant impacts are common at the end stages of planet accretion, similar mantle heterogeneities caused by impacts may also exist in the interiors of other planetary bodies.

Nature↗

USGS2003

Modeling the Radiance of the Moon for On-orbit Calibration

The RObotic Lunar Observatory (ROLO) project has developed radiometric models of the Moon for disk-integrated irradiance and spatially resolved radiance. Although the brightness of the Moon varies spatially and with complex dependencies upon illumination and viewing geometry, the surface photometric properties are extremely stable, and therefore potentially knowable to high accuracy. The ROLO project has acquired 5+ years of spatially resolved lunar images in 23 VNIR and 9 SWIR filter bands at phase angles up to 90??. These images are calibrated to exoatmospheric radiance using nightly stellar observations in a band-coupled extinction algorithm and a radiometric scale based upon observations of the star Vega. An effort is currently underway to establish an absolute scale with direct traceability to NIST radiometric standards. The ROLO radiance model performs linear fitting of the spatially resolved lunar image data on an individual pixel basis. The results are radiance images directly comparable to spacecraft observations of the Moon. Model-generated radiance images have been produced for the ASTER lunar view conducted on 14 April 2003. The radiance model is still experimental - simplified photometric functions have been used, and initial results show evidence of computational instabilities, particularly at the lunar poles. The ROLO lunar image dataset is unique and extensive and presents opportunities for development of novel approaches to lunar photometric modeling.

Conference Paper↗

USGS1976

Steps to the moon

On July 20, 1969, man walked on the surface of the Moon and began a new chapter of his studies that will eventually disclose the geologic nature of the Earth's nearest neighbor. Although he has finally reached the Moon and sampled its substance, much work and study remain before he will know the full scientific significance of the first landing. This booklet briefly summarizes the steps man has taken to understand the Moon and what he thinks he has learned to date as a result of his centuries-long speculations and studies.

General Information Product↗

USGS2007

Geologic map of the Craters of the Moon 30' x 60' Quadrangle, Idaho

The Craters of the Moon 30 x 60 minute quadrangle shows the geology of the northern two-thirds of the Craters of the Moon (COM) lava field and volcanic structures of the northern and central parts of the Great Rift volcanic rift zone. The COM lava field is the largest, predominantly Holocene lava field in the conterminous United States. The northwest corner of the map shows older sedimentary, intrusive, and volcanic rocks that range in age from Ordovician to Miocene. These rocks provide evidence of compressional fold and thrust events of the Antler and Sevier orogenies. Compression was followed by voluminous volcanism represented by the Challis Volcanic Group. Basin-and-Range faulting followed in Neogene time. The COM lava field covers about 1,600 square kilometers and contains about 30 cubic kilometers of lava flows and associated vent deposits. Stratigraphic relationships, paleomagnetic studies, and radiocarbon ages indicate that the field formed during eight eruptive periods designated as H, the oldest, to A, the youngest. Each eruptive period was several hundred years or less in duration and separated from other eruptive periods by non-eruptive recurrence intervals of several hundred to about 3,000 years. The first eruptive period began about 15,000 carbon-14 years ago and the latest one ended about 2,100 carbon-14 years ago. All available field, paleomagnetic, radiocarbon, and argon-40/argon-39 data are incorporated in this map and they quantitatively refine the volcanic and paleomagnetic history of the pre-Holocene lava fields and the COM lava field. In a sense, these data determine the 'pulse rate' for Pleistocene and Holocene basaltic volcanism in the area of this map. Twenty-three new argon-40/argon-39 geochronologic data reveal a fairly complete and continuous record of basaltic volcanism in the Craters of the Moon 30 x 60 minute quadrangle for the last 500 ka. The ages cluster into age groupings at ~30 ka, 50-70 ka, 100-125 ka, 260-290 ka, 320-340 ka, and 475 ka. There are apparent periods of ~30 to 60 ka duration when little or no volcanic activity took place between groups. Magnetic polarity and remanent inclination and declination directions for most lava flows in the quadrangle have normal magnetic polarity; they were emplaced during the Brunhes Normal Polarity Chron and are younger than 780,000 years. Directions of remanent magnetization and the new argon-40/argon-39 ages were used to correlate and approximately date lava flows and lava fields for this map.

Scientific Investigations Map↗

USGS2009

The Moon mineralogy mapper (M 3 ) on Chandrayaan-1

The Moon Mineralogy Mapper (M 3 ) is a NASA-supported guest instrument on ISRO's remote sensing mission to Moon, Chandrayaan-1. The M 3 is an imaging spectrometer that operates from the visible into the near-infrared (0.42-3.0 ??m) where highly diagnostic mineral absorption bands occur. Over the course of the mission M 3 will provide low resolution spectroscopic data for the entire lunar surface at 140 m/pixel (86 spectral channels) to be used as a base-map and high spectral resolution science data (80 m/pixel; 260 spectral channels) for 25-50% of the surface. The detailed mineral assessment of different lunar terrains provided by M 3 is principal information needed for understanding the geologic evolution of the lunar crust and lays the foundation for focused future in-depth exploration of the Moon.

Current Science↗

USGS1978

The moon: Composition determined by nebular processes

The bulk composition of the Moon was determined by the conditions in the solar nebula during its formation, and may be quantitatively estimated from the premise that the terrestrial planets were formed by cosmochemical processes similar to those recorded in the chondrites. The calculations are based on the Ganapathy-Anders 7-component model using trace element indicators, but incorportate improved geophysical data and petrological constraints. A model Moon with 40 ppb U, a core 2% by weight (1.8% metal with ???35% Ni and 0.2% FeS) and Mg/(Fe2++Mg)?????0.75 meets the trace element restrictions, and has acceptable density, heat flow and moment of inertia ratio. The high Ni content of the core permits low-Ti mare basalts to equilibrate with metal, yet still retain substantial Ni. The silicate resembles the Taylor-Jakes?? composition (and in some respects the waif Ganapathy-Anders Model 2a), but has lower SiO2. Minor modifications of the model composition (U=30-35 ppb) yield a 50% melt approximating Apollo 15 green glass and a residuum of olivine plus 3 to 4% spinel; the low SiO2, favors spinel formation, and, contrary to expectation, Cr is not depleted in the liquid. There may no longer be any inconsistency between the cosmochemical approach and arguments based on experimental petrology. ?? 1978 D. Reidel Publishing Company.

The Moon and the Planets↗

USGS1971

Two former faces of the moon

Systematic geologic mapping of the lunar near side has resulted in the assignment of relative ages to most visible features. As a derivative of this work, geologic and artistic interpretations have been combined to produce reconstructions of the Moon's appearance at two significant points in its history. The reconstructions, although generalized, show the Moon (1) as it probably appeared about 3.3 billion years ago after most of the mare materials had accumulated, and (2) about 4.0 billion years ago after formation of the youngest of the large multiringed basins, but prior to appreciable flooding by mare material.

Icarus↗

USGS2008

On developing thermal cave detection techniques for earth, the moon and mars

The purpose of this study is to (1) demonstrate the viability of detecting terrestrial caves at thermal-infrared wavelengths, (2) improve our understanding of terrestrial cave thermal behavior, (3) identify times of day when cave openings have the maximum thermal contrast with the surrounding surface regolith, and (4) further our understanding of how to detect caves on Earth, the Moon and Mars. We monitored the thermal behavior of two caves in the Atacama Desert of northern Chile. Through this work, we identified times when temperature contrasts between entrance and surface were greatest, thus enabling us to suggest optimal overflight times. The largest thermal contrast for both caves occurred during mid-day. One cave demonstrated thermal behavior at the entrance suggestive of cold-trapping, while the second cave demonstrated temperature shifts suggestive of airflow. We also collected thermograms without knowing optimal detection times; these images suggest both caves may also be detectable during off-peak times. We suggest cave detection using thermal remote sensing on Earth and other planetary objects will be limited by (1) capturing imagery in the appropriate thermal wavelength, (2) the size of cave entrance vs. the sensor's spatial resolution, (3) the viewing angle of the platform in relation to the slope trajectory of the cave entrance, (4) the strength of the thermal signal associated with the cave entrance, and (5) the time of day and season of thermal image capture. Through this and other studies, we will begin to identify the range of conditions under which caves are detectable in the thermal infrared and thus improve our detection capabilities of these features on Earth, the Moon and Mars.

Earth and Planetary Science Letters↗

USGS2010

A new look at photometry of the Moon

We use ROLO photometry (Kieffer, H.H., Stone, T.C. [2005]. Astron. J. 129, 2887-2901) to characterize the before and after full Moon radiance variation for a typical highlands site and a typical mare site. Focusing on the phase angle range 45??. <. ??<. 50??, we test two different physical models, macroscopic roughness and multiple scattering between regolith particles, for their ability to quantitatively reproduce the measured radiance difference. Our method for estimating the rms slope angle is unique and model-independent in the sense that the measured radiance factor I/. F at small incidence angles (high Sun) is used as an estimate of I/. F for zero roughness regolith. The roughness is determined from the change in I/. F at larger incidence angles. We determine the roughness for 23 wavelengths from 350 to 939. nm. There is no significant wavelength dependence. The average rms slope angle is 22.2?? ?? 1.3?? for the mare site and 34.1?? ?? 2.6?? for the highland site. These large slopes, which are similar to previous "photometric roughness" estimates, require that sub-mm scale "micro-topography" dominates roughness measurements based on photometry, consistent with the conclusions of Helfenstein and Shepard (Helfenstein, P., Shepard, M.K. [1999]. Icarus 141, 107-131). We then tested an alternative and very different model for the before and after full Moon I/. F variation: multiple scattering within a flat layer of realistic regolith particles. This model consists of a log normal size distribution of spheres that match the measured distribution of particles in a typical mature lunar soil 72141,1 (McKay, D.S., Fruland, R.M., Heiken, G.H. [1974]. Proc. Lunar Sci. Conf. 5, Geochim. Cosmochim. Acta 1 (5), 887-906). The model particles have a complex index of refraction 1.65-0.003. i, where 1.65 is typical of impact-generated lunar glasses. Of the four model parameters, three were fixed at values determined from Apollo lunar soils: the mean radius and width of the log normal size distribution and the real part of the refraction index. We used FORTRAN programs from Mishchenko et al. (Mishchenko, M.I., Dlugach, J.M., Yanovitskij, E.G., Zakharova, N.T. [1999]. J. Quant. Spectrosc. Radiat. Trans. 63, 409-432; Mishchenko, M.I., Travis, L.D., Lacis, A.A. [2002]. Scattering, Absorption and Emission of Light by Small Particles. Cambridge Univ. Press, New York. <. http://www.giss.nasa.gov/staff/mmishchenko/books.html>) to calculate the scattering matrix and solve the radiative transfer equation for I/. F. The mean single scattering albedo is ??=0.808, the asymmetry parameter is ???cos. ?????=0.77 and the phase function is very strongly peaked in both the forward and backward scattering directions. The fit to the observations for the highland site is excellent and multiply scattered photons contribute 80% of I/. F. We conclude that either model, roughness or multiple scattering, can match the observations, but that the strongly anisotropic phase functions of realistic particles require rigorous calculation of many orders of scattering or spurious photometric roughness estimates are guaranteed. Our multiple scattering calculation is the first to combine: (1) a regolith model matched to the measured particle size distribution and index of refraction of the lunar soil, (2) a rigorous calculation of the particle phase function and solution of the radiative transfer equation, and (3) application to lunar photometry with absolute radiance calibration. ?? 2010 Elsevier Inc.

Icarus↗

USGS2009

Moon meteoritic seismic hum: Steady state prediction

We use three different statistical models describing the frequency of meteoroid impacts on Earth to estimate the seismic background noise due to impacts on the lunar surface. Because of diffraction, seismic events on the Moon are typically characterized by long codas, lasting 1 h or more. We find that the small but frequent impacts generate seismic signals whose codas overlap in time, resulting in a permanent seismic noise that we term the "lunar hum" by analogy with the Earth's continuous seismic background seismic hum. We find that the Apollo era impact detection rates and amplitudes are well explained by a model that parameterizes (1) the net seismic impulse due to the impactor and resulting ejecta and (2) the effects of diffraction and attenuation. The formulation permits the calculation of a composite waveform at any point on the Moon due to simulated impacts at any epicentral distance. The root-mean-square amplitude of this waveform yields a background noise level that is about 100 times lower than the resolution of the Apollo long-period seismometers. At 2 s periods, this noise level is more than 1000 times lower than the low noise model prediction for Earth's microseismic noise. Sufficiently sensitive seismometers will allow the future detection of several impacts per day at body wave frequencies. Copyright 2009 by the American Geophysical Union.

Journal of Geophysical Research E: Planets↗

USGS2011

A wavelength-dependent visible and infrared spectrophotometric function for the Moon based on ROLO data

The USGS's Robotic Lunar Observatory (ROLO) dedicated ground‐based lunar calibration project obtained photometric observations of the Moon over the spectral range attainable from Earth (0.347–2.39 μ m) and over solar phase angles of 1.55°–97°. From these observations, we derived empirical lunar surface solar phase functions for both the highlands and maria that can be used for a wide range of applications. The functions can be used to correct for the effects of viewing geometry to produce lunar mosaics, spectra, and quick‐look products for future lunar missions and ground‐based observations. Our methodology can be used for a wide range of objects for which multiply scattered radiation is not significant, including all but the very brightest asteroids and moons.

Journal of Geophysical Research E: Planets↗