Geology topics

Jennifer L. Heldmann

Publications and source records attributed to Jennifer L. Heldmann.

3 recordsLinked to original sources

USGS2025

VIPER site analysis

We needed to evaluate available orbital data of NASA’s Volatiles Investigating Polar Exploration Rover (VIPER) mission area in order to derive a variety of maps to help the science team identify scientifically interesting places for the rover to visit and to provide scientific context for our mission. Some of these maps also fulfilled engineering and mission design needs to enable safe and efficient landing and roving. We incorporated data from the Lunar Reconnaissance Orbiter Camera, the Lunar Orbital Laser Altimeter, the Mini-RF instrument, the Chandrayaan-2 Orbital High Resolution Camera, the Korean Pathfinder Lunar Orbiter’s Shadowcam, the Kaguya Spectral Profiler and Multiband Imager, and the Chandrayaan-1 Moon Mineralogy Mapper. We used a variety of techniques to build these maps, including stereogrammetry, shape-from-shading, ice stability depth and surface temperature calculations, and the horizon method for solar illumination and direct-to-Earth communications maps. Altogether, these maps allowed us to survey for boulders, evaluate features in permanently shadowed regions that VIPER might explore, provide mineralogic context for what VIPER’s instruments may learn, estimate the ages and radar properties of craters in the VIPER mission area, and evaluate the potential for gravity traverses with the rover. These data and techniques provided a rich set of information from which both the VIPER science team and engineering teams were able to draw in order to plan a safe landing and to plan a VIPER surface mission that will be both scientifically valuable and robust from an operational perspective.

The Planetary Science Journal↗

USGS2025

Geomorphological evidence of near-surface ice at candidate landing sites in northern Amazonis Planitia, Mars

This work presents geomorphological analyses of an area at the boundary between Arcadia Planitia and northern Amazonis Planitia, situated in the northern mid-latitudes of Mars. Recent studies have indicated the presence of substantial volumes of near-surface excess ice in Arcadia Planitia, making this region a promising candidate for future human and robotic exploration. This study focuses on three specific candidate landing sites adjacent to the Arcadia Planitia: AP-1, AP-8, and AP-9. We have identified a wide range of ice-related morphologies, providing further evidence for the occurrence of excess ice in the study area. We have mapped and measured ∼9,000 thermal contraction polygons. We estimate ice beneath these polygons to be on the order of tens of cm from the surface, which is sufficiently shallow to be accessible for potential in situ resource utilization (ISRU). Recent impact craters that have been excavated into ice further suggest the presence of near-surface ice. Finally, the occurrence of ice and processes such as ice sublimation are likely responsible for the formation and subsequent modification of several observed features, including expanded craters, brain coral terrain, arcuate ridges, and thermal contraction polygons modified by sublimation. These results provide valuable insights into the ice distribution in the northern mid-latitudes and support the potential utilization of accessible ice resources for future human exploration efforts.

JGR Planets↗

USGS2017

The effects of snow and salt on ice table stability in University Valley, Antarctica

The Antarctic Dry Valleys represent a unique environment where it is possible to study dry permafrost overlaying an ice-rich permafrost. In this paper, two opposing mechanisms for ice table stability in University Valley are addressed: i) diffusive recharge via thin seasonal snow deposits and ii) desiccation via salt deposits in the upper soil column. A high-resolution time-marching soil and snow model was constructed and applied to University Valley, driven by meteorological station atmospheric measurements. It was found that periodic thin surficial snow deposits (observed in University Valley) are capable of drastically slowing (if not completely eliminating) the underlying ice table ablation. The effects of NaCl, CaCl 2 and perchlorate deposits were then modelled. Unlike the snow cover, however, the presence of salt in the soil surface (but no periodic snow) results in a slight increase in the ice table recession rate, due to the hygroscopic effects of salt sequestering vapour from the ice table below. Near-surface pore ice frequently forms when large amounts of salt are present in the soil due to the suppression of the saturation vapour pressure. Implications for Mars high latitudes are discussed.

Antarctic Science↗