Geology topics

Brett W. Denevi

Publications and source records attributed to Brett W. Denevi.

4 recordsLinked to original sources

USGS2026

Lunar-VISE landing site selection and characterization at Mons Gruithuisen Gamma

The Lunar Vulkan Imaging and Spectroscopy Explorer (Lunar-VISE) was selected for a Commercial Lunar Payload Services (CLPS) delivery to the Gruithuisen domes region of the Moon as part of NASA’s Payloads and Research Investigation on the Surface of the Moon (PRISM) program. The Gruithuisen domes are chemically and morphologically distinct from their surroundings with a thorium-rich, silicic composition. The Lunar-VISE instrument payload is designed to investigate the compositional and thermophysical properties of dome materials in order to understand how late-stage silicic volcanism occurred on the Moon. Selection of a landing site required balancing science and exploration goals with the safety requirements for landing and rover trafficability. Science required access to boulders, potential exposures of bedrock, and if possible, rover access to the dome edge to enable observations of the surrounding maria. Safety considerations included landing hazards, maintenance of line-of-sight communications between the lander and rover, and any early morning or late afternoon shadows that would limit the mission duration. After consideration of several candidate landing sites, a 100-meter diameter landing ellipse centered on 36.45715° N, 319.20398° E, was selected near the edge of a topographic step and blocky ejecta crater (recently named Mareta) near the summit of Mons Gruithuisen Gamma. This location enables access to a field of boulders excavated by a relatively fresh impact providing a diversity of boulders for investigations, as well as views to the surrounding mare and Mons Gruithuisen Delta dome off of the dome edge via only a short rover traverse outside the landing ellipse (traverse < 100 m) while meeting safety requirements in accord with the CLPS risk posture.

Planetary Science Journal↗

USGS2026

Morphometric properties of the CP-21 landing site on the Moon at Mons Gruithuisen Gamma

Characterizing terrain surface properties is an essential step in assessing the feasibility of landing successfully at a location on a planetary surface. Slopes and terrain ruggedness index (TRI) values derived from high-resolution (2 m pixel −1 ) digital terrain models provided important constraints in selecting the landing site for the upcoming Payloads and Research Investigations on the Surface of the Moon program as part of the Commercial Lunar Payload Services task order CP-21 mission. The selected landing site needed to balance safety requirements with the ability to achieve the science and exploration goals of the Lunar Vulkan Imaging and Spectroscopy Explorer payload. In this study, we compare several morphometric parameters in the context of the CP-21 landing site on Mons Gruithuisen Gamma, or the Gamma dome, and quantify the information they convey about lunar surface properties to assess their utility for future landing site evaluation. TRI was found to be a useful metric for assessing landing site safety. Metrics that better decouple slope and surface roughness, the vector ruggedness measure and the standard deviation of slope, provided additional information about surface characteristics and textures such as the degree to which roughness is isotropic.

Planetary Science Journal↗

USGS2021

A Next Generation Lunar Orbiter mission

The Moon is the scientific foundation for our knowledge of the early evolution and impact history of the terrestrial planets. Over the last decades the lunar science community has made significant progress in addressing key lunar science and exploration goals, while defining many new high-priority scientific questions regarding the formation and evolution of the Moon. On a broad scale, the last Planetary Decadal Survey defined three scientific objectives to guide studies of the inner planets and Moon. These objectives address the origins and diversity of terrestrial planets, the evolution of life on terrestrial planets, and climate processes on Earth-like planets [1]. Many of these objectives carry forward into exploration goals of a renewed lunar human exploration program, and urgently addressing these objectives will enable the rapid development of exploration plans. A large (Flagship or New Frontiers class) Next Generation Lunar Orbiter (NGLO) mission would address the last Planetary Decadal Survey objective of understanding the origin and diversity of terrestrial planets by studying the geochemistry and geology of the Moon at an unparalleled resolution compared to other lunar mission datasets. Also, NGLO would address the objective of studying the evolution of life on terrestrial planets by furthering knowledge about the composition and distribution of volatile elements on the lunar surface and better characterizing the past and present-day impact rates in the inner Solar System in order to better understand the original delivery of water to Earth. Key exploration goals, including identifying the nature and distribution of lunar volatiles (i.e., water, ice), mapping and characterizing potentially valuable lunar resources, and establishing a human presence on the Moon, also would be addressed by NGLO.

Bulletin of the AAS↗

USGS2018

Image mosaic and topographic maps of Mercury

Map Descriptions Sheet 1 : This image mosaic is based on observations acquired by the Mercury Dual Imaging System (MDIS; Hawkins and others, 2009), an instrument on the National Aeronautics and Space Agency (NASA) MErcury Surface, Space ENvironment, Geochemistry, and Ranging (MESSENGER) spacecraft (Solomon and others, 2007). The Mercator projection is used between latitudes ±57°, with a central meridian at 0° longitude and latitude equal to the nominal scale at 0°. The polar stereographic projection is used for the regions north of the +55° parallel and south of the –55° parallel, with a central meridian set for both at 0° and a latitude of true scale at +90° and –90°, respectively. All features greater than 100 km in diameter or length were included unless they were not visible at the printed map scale. Some selected well-known features less than 100 km in diameter or length were also included. For listed references, please open the full PDF. Sheet 2 : This map is based on data acquired by the Mercury Dual Imaging System (MDIS; Hawkins and others, 2009) and Mercury Laser Altimeter (MLA; Cavanaugh and others, 2007) instruments on the National Aeronautics and Space Agency (NASA) MErcury Surface, Space ENvironment, Geochemistry, and Ranging (MESSENGER) spacecraft (Solomon and others, 2007). The topographic shaded-relief maps were generated from the original MDIS- and MLA-based DEMs with a sun angle of 45° from horizontal and a sun azimuth of 270°, as measured clockwise from north, with no vertical exaggeration. The DEM values were then mapped to a global color look-up table, with each color representing a range of 1 km of elevation. The shaded-relief and color files were then merged and scaled to 1:20,000,000 for the Mercator portion and 1:12,157,366 for the two polar stereographic parts with a resolution of 300 pixels per inch. The two projections have a common scale at ±56° latitude. The Mercator projection is used between latitudes ±57°, with a central meridian at 0° longitude and latitude equal to the nominal scale at 0°. The polar stereographic projection is used for the regions north of the +55° parallel and south of the –55° parallel, with a central meridian set for both at 0° and a latitude of true scale at +90° and –90°, respectively. All features greater than 200 km in diameter or length were included unless they were not visible at the printed map scale. Some selected well-known features less than 200 km in diameter or length were also included. Sheet 2 is offered digitally as a layered PDF with two elevation color ramp options—the original printed version and a multicolored ramp developed by the MESSENGER team for their global products. For listed references, please open the full PDF.

Scientific Investigations Map↗