Search Results - "McEwen, Alfred S"

Spectral evidence for hydrated salts in recurring slope lineae on Mars by Ojha, Lujendra, Wilhelm, Mary Beth, Murchie, Scott L., McEwen, Alfred S., Wray, James J., Hanley, Jennifer, Massé, Marion, Chojnacki, Matt

“…Transient streaks that appear seasonally on Martian slopes are consistent with brine flows, but evidence of water or salts has been lacking. Analysis of…”
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Exposed subsurface ice sheets in the Martian mid-latitudes by Dundas, Colin M, Bramson, Ali M, Ojha, Lujendra, Wray, James J, Mellon, Michael T, Byrne, Shane, McEwen, Alfred S, Putzig, Nathaniel E, Viola, Donna, Sutton, Sarah, Clark, Erin, Holt, John W

“…Thick deposits cover broad regions of the Martian mid-latitudes with a smooth mantle; erosion in these regions creates scarps that expose the internal…”
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Granular flows at recurring slope lineae on Mars indicate a limited role for liquid water by Dundas, Colin M., McEwen, Alfred S., Chojnacki, Matthew, Milazzo, Moses P., Byrne, Shane, McElwaine, Jim N., Urso, Anna

“…Recent liquid water flow on Mars has been proposed based on geomorphological features, such as gullies. Recurring slope lineae — seasonal flows that are darker…”
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Seasonal Flows on Warm Martian Slopes by McEwen, Alfred S., Ojha, Lujendra, Dundas, Colin M., Mattson, Sarah S., Byrne, Shane, Wray, James J., Cull, Selby C., Murchie, Scott L., Thomas, Nicolas, Gulick, Virginia C.

“…Water probably flowed across ancient Mars, but whether it ever exists as a liquid on the surface today remains debatable. Recurring slope lineae (RSL) are…”
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Avalanche slope angles in low-gravity environments from active Martian sand dunes by Atwood-Stone, Corwin, McEwen, Alfred S.

“…The properties of granular material have an important effect on surface landforms and processes. Recently, it has been suggested that material properties…”
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Modeling the development of martian sublimation thermokarst landforms by Dundas, Colin M., Byrne, Shane, McEwen, Alfred S.

“…•A landscape evolution model for martian sublimation features is described.•Sublimation features suggest thick, clean subsurface ice.•Scalloped depressions can…”
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A Large New Crater Exposes the Limits of Water Ice on Mars by Dundas, Colin M., Mellon, Michael T., Posiolova, Liliya V., Miljković, Katarina, Collins, Gareth S., Tornabene, Livio L., Rangarajan, Vidhya Ganesh, Golombek, Matthew P., Warner, Nicholas H., Daubar, Ingrid J., Byrne, Shane, McEwen, Alfred S., Seelos, Kimberly D., Viola, Donna, Bramson, Ali M., Speth, Gunnar

“…Water ice in the Martian mid‐latitudes has advanced and retreated in response to variations in the planet's orbit, obliquity, and climate. A 150 m‐diameter new…”
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Seasonal activity and morphological changes in martian gullies by Dundas, Colin M., Diniega, Serina, Hansen, Candice J., Byrne, Shane, McEwen, Alfred S.

“…► Martian gully landforms are actively forming in the present climate. ► Gully activity includes formation of new channels and alcoves. ► Activity is…”
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HiRISE observations of new impact craters exposing Martian ground ice by Dundas, Colin M., Byrne, Shane, McEwen, Alfred S., Mellon, Michael T., Kennedy, Megan R., Daubar, Ingrid J., Saper, Lee

“…Twenty small new impact craters or clusters have been observed to excavate bright material inferred to be ice at mid‐latitudes and high latitudes on Mars. In…”
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Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) by McEwen, Alfred S., Eliason, Eric M., Bergstrom, James W., Bridges, Nathan T., Hansen, Candice J., Delamere, W. Alan, Grant, John A., Gulick, Virginia C., Herkenhoff, Kenneth E., Keszthelyi, Laszlo, Kirk, Randolph L., Mellon, Michael T., Squyres, Steven W., Thomas, Nicolas, Weitz, Catherine M.

“…The HiRISE camera features a 0.5 m diameter primary mirror, 12 m effective focal length, and a focal plane system that can acquire images containing up to 28…”
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A new analysis of Mars "Special Regions": findings of the second MEPAG Special Regions Science Analysis Group (SR-SAG2) by Rummel, John D, Beaty, David W, Jones, Melissa A, Bakermans, Corien, Barlow, Nadine G, Boston, Penelope J, Chevrier, Vincent F, Clark, Benton C, de Vera, Jean-Pierre P, Gough, Raina V, Hallsworth, John E, Head, James W, Hipkin, Victoria J, Kieft, Thomas L, McEwen, Alfred S, Mellon, Michael T, Mikucki, Jill A, Nicholson, Wayne L, Omelon, Christopher R, Peterson, Ronald, Roden, Eric E, Sherwood Lollar, Barbara, Tanaka, Kenneth L, Viola, Donna, Wray, James J

“…A committee of the Mars Exploration Program Analysis Group (MEPAG) has reviewed and updated the description of Special Regions on Mars as places where…”
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Distribution of Mid-Latitude Ground Ice on Mars from New Impact Craters by Byrne, Shane, Dundas, Colin M, Kennedy, Megan R, Mellon, Michael T, McEwen, Alfred S, Cull, Selby C, Daubar, Ingrid J, Shean, David E, Seelos, Kimberly D, Murchie, Scott L, Cantor, Bruce A, Arvidson, Raymond E, Edgett, Kenneth S, Reufer, Andreas, Thomas, Nicolas, Harrison, Tanya N, Posiolova, Liliya V, Seelos, Frank P

“…New impact craters at five sites in the martian mid-latitudes excavated material from depths of decimeters that has a brightness and color indicative of water…”
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THE IMPORTANCE OF SECONDARY CRATERING TO AGE CONSTRAINTS ON PLANETARY SURFACES by McEwen, Alfred S, Bierhaus, Edward B

“…Small craters (less than one kilometer diameter) can be primary craters produced by impact of interplanetary debris, or they can be secondary craters produced…”
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New and recent gully activity on Mars as seen by HiRISE by Dundas, Colin M., McEwen, Alfred S., Diniega, Serina, Byrne, Shane, Martinez-Alonso, Sara

“…Fresh‐appearing gully deposits are found at tens of sites in the southern hemisphere of Mars. These deposits have latitudinal and azimuthal dependences similar…”
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Revealing Active Mars with HiRISE Digital Terrain Models by Sutton, Sarah S., Chojnacki, Matthew, McEwen, Alfred S., Kirk, Randolph L., Dundas, Colin M., Schaefer, Ethan I., Conway, Susan J., Diniega, Serina, Portyankina, Ganna, Landis, Margaret E., Baugh, Nicole F., Heyd, Rodney, Byrne, Shane, Tornabene, Livio L., Ojha, Lujendra, Hamilton, Christopher W.

“…Many discoveries of active surface processes on Mars have been made due to the availability of repeat high-resolution images from the High Resolution Imaging…”
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An impact origin for hydrated silicates on Mars: A synthesis by Tornabene, Livio L., Osinski, Gordon R., McEwen, Alfred S., Wray, James J., Craig, Michael A., Sapers, Haley M., Christensen, Philip R.

“…Recent Mars‐orbiting spectrometers continue to detect surface materials containing hydrated silicates, particularly clays and amorphous phases (e.g., silica…”
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Widespread crater-related pitted materials on Mars: Further evidence for the role of target volatiles during the impact process by Tornabene, Livio L., Osinski, Gordon R., McEwen, Alfred S., Boyce, Joseph M., Bray, Veronica J., Caudill, Christy M., Grant, John A., Hamilton, Christopher W., Mattson, Sarah, Mouginis-Mark, Peter J.

“…► Identification of a globally widespread crater-related pitted material. ► Pits are shown to scale proportionately with the host crater’s diameter. ► Presents…”
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Quasi-Periodic Bedding in the Sedimentary Rock Record of Mars by Lewis, Kevin W, Aharonson, Oded, Grotzinger, John P, Kirk, Randolph L, McEwen, Alfred S, Suer, Terry-Ann

“…Widespread sedimentary rocks on Mars preserve evidence of surface conditions different from the modern cold and dry environment, although it is unknown how…”
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New crater on the Moon and a swarm of secondaries by Robinson, Mark S., Boyd, Aaron K., Denevi, Brett W., Lawrence, Samuel J., McEwen, Alfred S., Moser, Danielle E., Povilaitis, Reinhold Z., Stelling, Richard W., Suggs, Robert M., Thompson, Shane D., Wagner, Robert V.

“…•LROC images revealed a new 18.8m diameter crater formed on 17 March 2013.•Details of ejecta distribution and the structure of the regolith are…”
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Fracture-Controlled Paleo-Fluid Flow in Candor Chasma, Mars by Okubo, Chris H, McEwen, Alfred S

“…Color observations from the High Resolution Imaging Science Experiment on board the Mars Reconnaissance Orbiter reveal zones of localized fluid alteration…”
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