Search Results - "Lillis, R. J."

Weak magnetism of Martian impact basins may reflect cooling in a reversing dynamo by Steele, S. C., Fu, R. R., Mittelholz, A., Ermakov, A. I., Citron, R. I., Lillis, R. J.

“…Understanding the longevity of Mars’s dynamo is key to interpreting the planet’s atmospheric loss history and the properties of its deep interior. Satellite…”
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MAVEN observations of the solar cycle 24 space weather conditions at Mars by Lee, C. O., Hara, T., Halekas, J. S., Thiemann, E., Chamberlin, P., Eparvier, F., Lillis, R. J., Larson, D. E., Dunn, P. A., Espley, J. R., Gruesbeck, J., Curry, S. M., Luhmann, J. G., Jakosky, B. M.

“…The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has been continuously observing the variability of solar soft X‐rays and EUV irradiance,…”
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Ion Densities in the Nightside Ionosphere of Mars: Effects of Electron Impact Ionization by Girazian, Z., Mahaffy, P., Lillis, R. J., Benna, M., Elrod, M., Fowler, C. M., Mitchell, D. L.

“…We use observations from the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission to show how superthermal electron fluxes and crustal magnetic fields affect…”
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Rapid decrease in Martian crustal magnetization in the Noachian era: Implications for the dynamo and climate of early Mars by Lillis, R. J., Frey, H. V., Manga, M.

“…The magnetic signatures and crater retention ages of the 19 largest (>1000 km diameter) impact basins on Mars are examined to constrain the history of the…”
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Variations in Nightside Magnetic Field Topology at Mars by Brain, D. A., Weber, T., Xu, S., Mitchell, D. L., Lillis, R. J., Halekas, J. S., Espley, J., Jakosky, B. M.

“…The Martian plasma environment contains a complex magnetic topology, with contributions from the interplanetary magnetic field (IMF) and crustal magnetic…”
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The spatial distribution of planetary ion fluxes near Mars observed by MAVEN by Brain, D. A., McFadden, J. P., Halekas, J. S., Connerney, J. E. P., Bougher, S. W., Curry, S., Dong, C. F., Dong, Y., Eparvier, F., Fang, X., Fortier, K., Hara, T., Harada, Y., Jakosky, B. M., Lillis, R. J., Livi, R., Luhmann, J. G., Ma, Y., Modolo, R., Seki, K.

“…We present the results of an initial effort to statistically map the fluxes of planetary ions on a closed surface around Mars. Choosing a spherical shell ~1000…”
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Magnetic Field Signatures of Craters on Mars by Mittelholz, A., Steele, S. C., Fu, R. R., Johnson, C. L., Lillis, R. J., Stucky de Quay, G.

“…Craters on Mars are a window into Mars' past and the time they were emplaced. Because the crust is heated and shocked during impact, craters can demagnetize or…”
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Giant impacts on early Mars and the cessation of the Martian dynamo by Roberts, J. H., Lillis, R. J., Manga, M.

“…Although Mars currently has no global dynamo‐driven magnetic field, widespread crustal magnetization provides strong evidence that such a field existed in the…”
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Observations of the nightside ionosphere of Mars by the Mars Express Radio Science Experiment (MaRS) by Withers, Paul, Fillingim, M. O., Lillis, R. J., Häusler, B., Hinson, D. P., Tyler, G. L., Pätzold, M., Peter, K., Tellmann, S., Witasse, O.

“…The vertical structure of the nightside ionosphere of Mars and its dependence on solar zenith angle are currently poorly determined, as is the importance of…”
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MAVEN measured oxygen and hydrogen pickup ions: Probing the Martian exosphere and neutral escape by Rahmati, A., Larson, D. E., Cravens, T. E., Lillis, R. J., Halekas, J. S., McFadden, J. P., Dunn, P. A., Mitchell, D. L., Thiemann, E. M. B., Eparvier, F. G., DiBraccio, G. A., Espley, J. R., Mazelle, C., Jakosky, B. M.

“…Soon after the MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft started orbiting Mars, the SEP (Solar Energetic Particle), SWIA (Solar Wind Ion…”
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MAVEN SEP Observations of Scorpius X‐1 X‐Rays at Mars: A Midatmosphere Occultation Analysis Technique by Rahmati, A., Larson, D. E., Cravens, T. E., Lillis, R. J., Lee, C. O., Dunn, P. A.

“…We report on the first observations of atmospheric occultations at Mars of ~10 keV X‐rays from an extrasolar source identified as Scorpius X‐1. The…”
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MAVEN observations of solar wind hydrogen deposition in the atmosphere of Mars by Halekas, J. S., Lillis, R. J., Mitchell, D. L., Cravens, T. E., Mazelle, C., Connerney, J. E. P., Espley, J. R., Mahaffy, P. R., Benna, M., Jakosky, B. M., Luhmann, J. G., McFadden, J. P., Larson, D. E., Harada, Y., Ruhunusiri, S.

“…Mars Atmosphere and Volatile EvolutioN mission (MAVEN) observes a tenuous but ubiquitous flux of protons with the same energy as the solar wind in the Martian…”
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Test Particle Model Predictions of SEP Electron Transport and Precipitation at Mars by Jolitz, R. D., Dong, C. F., Rahmati, A., Brain, D. A., Lee, C. O., Lillis, R. J., Curry, S. M., Jakosky, B. M.

“…Extreme space weather events can episodically release solar energetic particles (SEPs) that precipitate into planetary atmospheres, leading to aurora and…”
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Electron pitch angle distributions as indicators of magnetic field topology near Mars by Brain, D. A., Lillis, R. J., Mitchell, D. L., Halekas, J. S., Lin, R. P.

“…We have analyzed electron angular distributions recorded near Mars over a period of 7 years in order to constrain the topology of magnetic field lines near…”
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Comparative study of the Martian suprathermal electron depletions based on Mars Global Surveyor, Mars Express, and Mars Atmosphere and Volatile EvolutioN mission observations by Steckiewicz, M., Garnier, P., André, N., Mitchell, D. L., Andersson, L., Penou, E., Beth, A., Fedorov, A., Sauvaud, J.‐A., Mazelle, C., Brain, D. A., Espley, J. R., McFadden, J., Halekas, J. S., Larson, D. E., Lillis, R. J., Luhmann, J. G., Soobiah, Y., Jakosky, B. M.

“…Nightside suprathermal electron depletions have been observed at Mars by three spacecraft to date: Mars Global Surveyor, Mars Express, and the Mars Atmosphere…”
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Maven Observations of Electron-Induced Whistler Mode Waves in the Martian Magnetosphere by Harada, Y., Andersson, L., Fowler, C. M., Mitchell, D. L., Halekas, J. S., Mazelle, C., Espley, J., DiBraccio, G. A., McFadden, J. P., Brian, D. A., Xu, S., Ruhunusiri, S., Larson, D. E., Lillis, R. J., Hara, T., Livi, R., Jakosky, B. M.

“…We report on narrowband electromagnetic waves at frequencies between the local electron cyclotron and lower hybrid frequencies observed by the Mars Atmosphere…”
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MAVEN Observations of Energy-Time Dispersed Electron Signatures in Martian Crustal Magnetic Fields by Harada, Y., Mitchell, D. L., Halekas, J. S., McFadden, J. P., Mazelle, C., Connerney, J. E. P., Espley, J., Brain, D. A., Larson, D. E., Lillis, R. J., Hara, T., Livi, R., DiBraccio, G. A., Ruhunusiri, S., Jakosky, B. M.

“…Energy-time dispersed electron signatures are observed by the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission in the vicinity of strong Martian crustal…”
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Pickup ion measurements by MAVEN: A diagnostic of photochemical oxygen escape from Mars by Rahmati, A., Cravens, T. E., Nagy, A. F., Fox, J. L., Bougher, S. W., Lillis, R. J., Ledvina, S. A., Larson, D. E., Dunn, P., Croxell, J. A.

“…A key process populating the oxygen exosphere at Mars is the dissociative recombination of ionospheric O2+, which produces fast oxygen atoms, some of which…”
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Global‐scale external magnetic fields at Mars measured at satellite altitude by Mittelholz, A., Johnson, C. L., Lillis, R. J.

“…The Martian magnetic field is unique among those of the terrestrial planets. It is the net result of the interaction of the solar wind and the interplanetary…”
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Seasonal Variability of Neutral Escape from Mars as Derived From MAVEN Pickup Ion Observations by Rahmati, A., Larson, D. E., Cravens, T. E., Lillis, R. J., Halekas, J. S., McFadden, J. P., Mitchell, D. L., Thiemann, E. M. B., Connerney, J. E. P., Dunn, P. A., Lee, C. O., Eparvier, F. G., DiBraccio, G. A., Espley, J. R., Luhmann, J. G., Mazelle, C., Jakosky, B. M.

“…The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft arrived at Mars with the goal of determining the rates and mechanisms of atmospheric escape…”
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