116 citations · 285 across the 13 of their papers we have counts for
14 papers
Sealing Europa's vents by vapor deposition: An order of magnitude study
Stefano Boccelli, Shane R. Carberry Mogan, Robert E. Johnson +1
Fractures and vents in the ice crust of Europa, exposing the sub-surface ocean or liquid-water inclusions to the vacuum, might be responsible for the generation of water-vapor plum…
Absolute Doubly Differential Angular Sputtering Yields for 20 keV Kr+ on Polycrystalline Cu
Caixia Bu, Liam S. Morrissey, Benjamin C. Bostick +16
We have measured the absolute doubly differential angular sputtering yield for 20 keV Kr+ impacting a polycrystalline Cu slab at an incidence angle of θi = 45° relative to the surf…
In-situ Optimized Substrate Witness Plates: Ground Truth for Key Processes on the Moon and Other Planets
Prabal Saxena, Liam S. Morrissey, Rosemary M. Killen +12
Future exploration efforts of the Moon, Mars and other bodies are poised to focus heavily on persistent and sustainable survey and research efforts, especially given the recent int…
Callisto's atmosphere: First evidence for H2 and constraints on H2O
Shane R. Carberry Mogan, Orenthal J. Tucker, Robert E. Johnson +8
We explore the parameter space for the contribution to Callisto's H corona observed by the Hubble Space Telescope (Roth et al. 2017a) from sublimated H2O and radiolytically produce…
The influence of upper boundary conditions on molecular kinetic atmospheric escape simulations
S. R. Carberry Mogan, O. J. Tucker, R. E. Johnson
Molecular kinetic simulations are typically used to accurately describe the tenuous regions of the upper atmospheres on planetary bodies. These simulations track the motion of part…
A tenuous, collisional atmosphere on Callisto
Shane Carberry Mogan, Orenthal Tucker, Robert Johnson +7
A simulation tool which utilizes parallel processing is developed to describe molecular kinetics in 2D, single-and multi-component atmospheres on Callisto. This expands on our prev…
Persephone: A Pluto-System Orbiter and Kuiper Belt Explorer
Carly Howett, Stuart Robbins, Bryan J. Holler +40
Persephone is a NASA concept mission study that addresses key questions raised by New Horizons' encounters with Kuiper Belt objects (KBOs), with arguably the most important being "…
On the Effect of Magnetospheric Shielding on the Lunar Hydrogen Cycle
Orenthal J. Tucker, William M. Farrell, Andrew R. Poppe
We examine how water is produced globally over the lunar surface as it orbits in/out of the magnetotail. Due to the interaction of the solar wind (SW) with Earth's magnetic field,…
Lifetime of a transient atmosphere produced by Lunar Volcanism
Orenthal J. Tucker, Rosemary M. Killen, Robert E. Johnson +1
Early in the Moon's history volcanic outgassing may have produced a periodic millibar level atmosphere (Needham and Kring, 2017). We examined the relevant atmospheric escape proces…
The Science Case for a Titan Flagship-class Orbiter with Probes
Conor A. Nixon, James Abshire, Andrew Ashton +36
We outline a flagship-class mission concept focused on studying Titan as a global system, with particular emphasis on the polar regions. Investigating Titan from the unique standpo…
Propagation of Transient Perturbations into a Planet's Exosphere: Molecular Kinetic Simulations
Ludivine Leclercq, Robert E. Johnson, Hayley H Williamson +1
The upper atmospheres of Mars and Titan, as well as those on many other planetary bodies, exhibit significant density variations vs. altitude that are interpreted as gravity waves.…
Evolution of an Early Titan Atmosphere: Comment
Robert E Johnson, Orenthal J. Tucker, Alexey N. Volkov
Escape of an early atmosphere from Titan, during which time NH3 could be converted by photolysis into the present N2 dominated atmosphere, is an important problem in planetary scie…
Thermally driven escape from Pluto's atmosphere: A combined fluid/kinetic model
O. J. Tucker, J. T. Erwin, J. I. Deighan +2
A combined fluid/kinetic model is developed to calculate thermally driven escape of N2 from Pluto's atmosphere for two solar heating conditions: no heating above 1450 km and solar…
Thermally-driven atmospheric escape: Transition from hydrodynamic to Jeans escape
Alexey N. Volkov, Robert E. Johnson, Orenthal J. Tucker +1
Thermally-driven atmospheric escape evolves from an organized outflow (hydrodynamic escape) to escape on a molecule by molecules basis (Jeans escape) with increasing Jeans paramete…