Open AccessModeling of the vapor release from the LCROSS impact: 2. Observations from LAMP
Author(s) -
Hurley Dana M.,
Gladstone G. Randall,
Stern S. Alan,
Retherford Kurt D.,
Feldman Paul D.,
Pryor Wayne,
Egan Anthony F.,
Greathouse Thomas K.,
Kaufmann David E.,
Steffl Andrew J.,
Parker Joel William,
Miles Paul F.,
Horvath David,
Davis Michael W.,
Versteeg Maarten H.,
Slater David C.,
Hendrix Amanda R.,
Hibbitts Charles A.,
Ernst Carolyn M.,
Vervack Ronald J.,
Grieves Gregory A.
Publication year - 2012
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2011je003841
Subject(s) - plume , impact crater , isotropy , orbiter , spectrograph , ultraviolet , light curve , water vapor , physics , atmospheric sciences , astrophysics , analytical chemistry (journal) , materials science , optics , spectral line , meteorology , chemistry , astrobiology , astronomy , environmental chemistry
Using a Monte Carlo model, we analyze the evolution of the vapor plume emanating from the Lunar Crater Observation and Sensing Satellite (LCROSS) impact into Cabeus as seen by the Lyman Alpha Mapping Project (LAMP), a far‐ultraviolet (FUV) imaging spectrograph onboard the Lunar Reconnaissance Orbiter. The best fit to the data utilizes a bulk velocity between 3.0 and 4.0 km/s. The fits to the light curve comprised of Hg, Ca, and Mg are not strongly dependent on the temperature. In contrast, the best fit to the light curve from H 2 and CO corresponds to a 500 K thermal velocity distribution. The LAMP field of view primarily encounters particles released at low angles to the horizontal and misses fast moving particles released at more vertical angles. The isotropic model suggests that 117 ± 16 kg H 2 , 41 ± 3 kg CO, 16 ± 1 kg Ca, 12.4 ± 0.8 kg Hg, and 3.8 ± 0.3 kg Mg are released by the LCROSS impact. Additional errors could arise from an anisotropic plume, which cannot be distinguished with LAMP data. Mg and Ca are likely incompletely volatilized owing to their high vapor temperatures. The highly volatile components (H 2 and CO) might derive from a greater mass of material. To agree with predicted abundances by weight of 0.047%, 0.023%, 11%, 0.28% and 3.4% for H 2 , CO, Ca, Hg, and Mg, respectively, the species would be released from 250,000 kg, 180,000 kg, 140 kg, 4400 kg, and 110 kg of regolith, respectively. This is consistent with the relative volatility of these species.