Justin Hagerty
Science and Products
Thorium abundances on the Aristarchus plateau: Insights into the composition of the Aristarchus pyroclastic glass deposits
Thorium (Th) data from the Lunar Prospector gamma ray spectrometer (LP‐GRS) are used to constrain the composition of lunar pyroclastic glass deposits on top of the Aristarchus plateau. Our goal is to use forward modeling of LP‐GRS Th data to measure the Th abundances on the plateau and then to determine if the elevated Th abundances on the plateau...
Hagerty, Justin J.; Lawrence, D. J.; Hawke, B. R.; Gaddis, Lisa R. Composition and origin of the Dewar geochemical anomaly
Dewar crater is a 50-km diameter impact structure located in the highlands northwest of the South Pole–Aitken basin on the lunar farside. A low-albedo area with enhanced Th and Sm values is centered east-northeast of Dewar crater. This area also exhibits elevated FeO abundances (9.0–16.6 wt %) and TiO2 values (0.6–2 wt %). The range of FeO...
Lawrence, Samuel J.; Hawke, B. Ray; Gillis-Davis, Jeffrey J.; Taylor, G. Jeffrey; Lawrence, David J.; Cahill, Joshua T.; Hagerty, Justin J.; Lucey, Paul G.; Smith, Gregory A.; Keil, Klaus Vertical distribution of hydrogen at high northern latitudes on Mars: The Mars Odyssey Neutron Spectrometer
Neutron leakage currents measured using the Mars Odyssey Neutron Spectrometer are used to develop a two‐layer model of the distribution of hydrogen (here parameterized as water‐equivalent hydrogen, WEH) at high northern latitudes. The WEH abundance in the upper layer, Wup, was found to range between 1% and about 5%. The maximum value of the...
Feldman, William C.; Mellon, Michael T.; Gasnault, Olivier; Diez, B.; Elphic, R.C.; Hagerty, Justin J.; Lawrence, D. J.; Maurice, S.; Prettyman, T.H. Global spatial deconvolution of Lunar Prospector Th abundances
We have completed the first global spatial deconvolution analysis of planetary gamma‐ray data for lunar Th abundances as measured by the Lunar Prospector Gamma‐ray Spectrometer. We tested two different spatial deconvolution techniques – Jansson's method and the Pixon method – and determined that the Pixon method provides superior performance. The...
Lawrence, D. J.; Puetter, R.C.; Elphic, R.C.; Feldman, W.C.; Hagerty, Justin J.; Prettyman, Thomas H.; Spudis, P.D. Heat-producing elements in the lunar mantle: Insights from ion microprobe analyses of lunar pyroclastic glasses
We provide new estimates for the abundance of heat-producing elements in the lunar mantle by using SIMS techniques to measure the concentrations of thorium and samarium in lunar pyroclastic glasses. Lunar pyroclastic glasses are utilized in this study because they represent quenched products of near-primary melts from the lunar mantle and as such...
Hagerty, Justin J.; Shearer, Charles K.; Vaniman, David Refined thorium abundances for lunar red spots: Implications for evolved, nonmare volcanism on the Moon
We have used improved knowledge of the spatial distribution of thorium (Th) on the lunar surface, in conjunction with a forward modeling analysis of Lunar Prospector gamma ray data, to estimate the thorium abundances of lunar red spots. The results from this study can be combined with preexisting compositional and morphologic evidence to suggest...
Hagerty, Justin J.; Lawrence, D. J.; Hawke, B. R.; Vaniman, D. T.; Elphic, R.C.; Feldman, William C. Identifying the effects of petrologic processes in a closed basaltic system using trace element concentrations in olivines and glasses: Implications for comparative planetology
We use trace-element concentrations in olivines and glasses from a closed basaltic system to identify the effects of petrologic processes on the trace-element record of that system. The closed basaltic system in question is the Makaopuhi Lava Lake (MLL), which is closed with respect to magma mixing. Detailed studies of this lava lake have provided...
Hagerty, Justin J.; Shearer, Charles K.; Vaniman, David; Burger, Paul V. Petrogenesis of the Apollo 14 high-alumina basalts: Implications from ion microprobe analyses
In this study, ion microprobe analyses of individual minerals are used to investigate the petrogenesis of the Apollo 14 high-Al basalts. We use trace element concentrations from individual minerals in the Apollo 14 high-Al basalts to evaluate both endogenic and exogenic models. The data show that if the Apollo 14 high-Al basalts were produced by...
Hagerty, Justin J.; Shearer, Charles K.; Papike, James J. Hydrothermal alteration at the Lonar Lake impact structure, India: Implications for impact cratering on Mars
The 50,000 year old, 1.8 km diameter Lonar crater is one of only two known terrestrial craters to be emplaced in basaltic target rock (the 65 million year old Deccan Traps). The composition of the Lonar basalts is similar to martian basaltic meteorites, which establishes Lonar as an excellent analogue for similarly sized craters on the surface of...
Hagerty, Justin J.; Newsom, Horton E.