ALBERT

Description: This study provides the first observations of Plutogenic ions and their unique interaction with the solar wind. We find ~20% solar wind slowing that maps to a point only ~4.5 R P upstream of Pluto and a bow shock most likely produced by comet-like mass loading. The Pluto obstacle is a region of dense heavy ions bounded by a “Plutopause” where the solar wind is largely excluded, and which extends back 〉100 R P into a heavy ion tail. The upstream standoff distance is at only ~2.5 R P . The heavy ion tail contains considerable structure, may still be partially threaded by the IMF, and is surrounded by a light ion sheath. The heavy ions (presumably CH 4 + ) have average speed, density, and temperature of ~90 km s -1 , ~0.009 cm -3 , and ~7x10 5 K, with significant variability, slightly increasing speed/temperature with distance and are N-S asymmetric. Density and temperature are roughly anti-correlated yielding a pressure ~2 x10 -2 pPa, roughly in balance with the interstellar pickup ions at ~33 AU. We set an upper bound of 〈30 nT surface field at Pluto and argue that the obstacle is largely produced by atmospheric thermal pressure like Venus and Mars; we also show that the loss rate down the tail (~5 x10 23 s -1 ) is only ~1% of the expected total CH 4 loss rate from Pluto. Finally, we observe a burst of heavy ions upstream from the bow shock as they are becoming picked up and tentatively identify an IMF outward sector at the time of the NH flyby.

Description: Convection in a volatile nitrogen-ice-rich layer drives Pluto’s geological vigour Nature 534, 7605 (2016). doi:10.1038/nature18289 Authors: William B. McKinnon, Francis Nimmo, Teresa Wong, Paul M. Schenk, Oliver L. White, J. H. Roberts, J. M. Moore, J. R. Spencer, A. D. Howard, O. M. Umurhan, S. A. Stern, H. A. Weaver, C. B. Olkin, L. A. Young & K. E. Smith The vast, deep, volatile-ice-filled basin informally named Sputnik Planum is central to Pluto’s vigorous geological activity. Composed of molecular nitrogen, methane, and carbon monoxide ices, but dominated by nitrogen ice, this layer is organized into cells or polygons, typically about 10 to 40 kilometres across, that resemble the surface manifestation of solid-state convection. Here we report, on the basis of available rheological measurements, that solid layers of nitrogen ice with a thickness in excess of about one kilometre should undergo convection for estimated present-day heat-flow conditions on Pluto. More importantly, we show numerically that convective overturn in a several-kilometre-thick layer of solid nitrogen can explain the great lateral width of the cells. The temperature dependence of nitrogen-ice viscosity implies that the ice layer convects in the so-called sluggish lid regime, a unique convective mode not previously definitively observed in the Solar System. Average surface horizontal velocities of a few centimetres a year imply surface transport or renewal times of about 500,000 years, well under the ten-million-year upper-limit crater retention age for Sputnik Planum. Similar convective surface renewal may also occur on other dwarf planets in the Kuiper belt, which may help to explain the high albedos shown by some of these bodies.

Description: Corrigendum: Convection in a volatile nitrogen-ice-rich layer drives Pluto’s geological vigour Nature 537, 7618 (2016). doi:10.1038/nature18937 Authors: William B. McKinnon, Francis Nimmo, Teresa Wong, Paul M. Schenk, Oliver L. White, J. H. Roberts, J. M. Moore, J. R. Spencer, A. D. Howard, O. M. Umurhan, S. A. Stern, H. A. Weaver, C. B. Olkin, L. A. Young & K. E. Smith Nature534, 82–85 (2016); doi:10.1038/nature18289In the list of the New Horizons Geology, Geophysics and Imaging Theme Team, two members were inadvertently omitted: Richard P. Binzel and Alissa Earle (both affiliated with Massachusetts Institute of Technology, Cambridge, Massachusetts

Description: Author(s): E. J. Zirnstein, D. J. McComas, R. Kumar, H. A. Elliott, J. R. Szalay, C. B. Olkin, J. Spencer, S. A. Stern, and L. A. Young Measurements made by NASA’s New Horizons spacecraft show that shockwaves in the solar wind transfer significant energy to ionized interstellar atoms, confirming a decades-old prediction. [Phys. Rev. Lett. 121, 075102] Published Fri Aug 17, 2018

Description: Several observations of Jupiter's atmosphere made by instruments on the New Horizons spacecraft have implications for the stability and dynamics of Jupiter's weather layer. Mesoscale waves, first seen by Voyager, have been observed at a spatial resolution of 11 to 45 kilometers. These waves have a 300-kilometer wavelength and phase velocities greater than the local zonal flow by 100 meters per second, much higher than predicted by models. Additionally, infrared spectral measurements over five successive Jupiter rotations at spatial resolutions of 200 to 140 kilometers have shown the development of transient ammonia ice clouds (lifetimes of 40 hours or less) in regions of strong atmospheric upwelling. Both of these phenomena serve as probes of atmospheric dynamics below the visible cloud tops.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Reuter, D C -- Simon-Miller, A A -- Lunsford, A -- Baines, K H -- Cheng, A F -- Jennings, D E -- Olkin, C B -- Spencer, J R -- Stern, S A -- Weaver, H A -- Young, L A -- New York, N.Y. -- Science. 2007 Oct 12;318(5848):223-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉NASA Goddard Space Flight Center, Code 693, Greenbelt, MD 20771, USA. dennis.c.reuter@nasa.gov〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17932284" target="_blank"〉PubMed〈/a〉

Description: The New Horizons spacecraft observed Jupiter's icy satellites Europa and Ganymede during its flyby in February and March 2007 at visible and infrared wavelengths. Infrared spectral images map H2O ice absorption and hydrated contaminants, bolstering the case for an exogenous source of Europa's "non-ice" surface material and filling large gaps in compositional maps of Ganymede's Jupiter-facing hemisphere. Visual wavelength images of Europa extend knowledge of its global pattern of arcuate troughs and show that its surface scatters light more isotropically than other icy satellites.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Grundy, W M -- Buratti, B J -- Cheng, A F -- Emery, J P -- Lunsford, A -- McKinnon, W B -- Moore, J M -- Newman, S F -- Olkin, C B -- Reuter, D C -- Schenk, P M -- Spencer, J R -- Stern, S A -- Throop, H B -- Weaver, H A -- New Horizons Team -- New York, N.Y. -- Science. 2007 Oct 12;318(5848):234-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA. mshowalter@seti.org〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17932288" target="_blank"〉PubMed〈/a〉

Description: A stellar-occultation light curve for Triton shows asymmetry that can be understood if Triton's middle atmosphere is distorted from spherical symmetry. Although a globally oblate model can explain the data, the inferred atmospheric flattening is so large that it could be caused only by an unrealistic internal mass distribution or highly supersonic zonal winds. Cyclostrophic winds confined to a jet near Triton's northern or southern limbs (or both) could also be responsible for the details of the light curve, but such winds are required to be slightly supersonic. Hazes and clouds in the atmosphere are unlikely to have caused the asymmetry in the light curve.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Elliot, J L -- Stansberry, J A -- Olkin, C B -- Agner, M A -- Davies, M E -- New York, N.Y. -- Science. 1997 Oct 17;278(5337):436-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth, Atmospheric, and Planetary Sciences and Department of Physics, Building 54-422, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA. jle@mit.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9334297" target="_blank"〉PubMed〈/a〉

Description: The Pluto system was recently explored by NASA's New Horizons spacecraft, making closest approach on 14 July 2015. Pluto's surface displays diverse landforms, terrain ages, albedos, colors, and composition gradients. Evidence is found for a water-ice crust, geologically young surface units, surface ice convection, wind streaks, volatile transport, and glacial flow. Pluto's atmosphere is highly extended, with trace hydrocarbons, a global haze layer, and a surface pressure near 10 microbars. Pluto's diverse surface geology and long-term activity raise fundamental questions about how small planets remain active many billions of years after formation. Pluto's large moon Charon displays tectonics and evidence for a heterogeneous crustal composition; its north pole displays puzzling dark terrain. Small satellites Hydra and Nix have higher albedos than expected.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stern, S A -- Bagenal, F -- Ennico, K -- Gladstone, G R -- Grundy, W M -- McKinnon, W B -- Moore, J M -- Olkin, C B -- Spencer, J R -- Weaver, H A -- Young, L A -- Andert, T -- Andrews, J -- Banks, M -- Bauer, B -- Bauman, J -- Barnouin, O S -- Bedini, P -- Beisser, K -- Beyer, R A -- Bhaskaran, S -- Binzel, R P -- Birath, E -- Bird, M -- Bogan, D J -- Bowman, A -- Bray, V J -- Brozovic, M -- Bryan, C -- Buckley, M R -- Buie, M W -- Buratti, B J -- Bushman, S S -- Calloway, A -- Carcich, B -- Cheng, A F -- Conard, S -- Conrad, C A -- Cook, J C -- Cruikshank, D P -- Custodio, O S -- Dalle Ore, C M -- Deboy, C -- Dischner, Z J B -- Dumont, P -- Earle, A M -- Elliott, H A -- Ercol, J -- Ernst, C M -- Finley, T -- Flanigan, S H -- Fountain, G -- Freeze, M J -- Greathouse, T -- Green, J L -- Guo, Y -- Hahn, M -- Hamilton, D P -- Hamilton, S A -- Hanley, J -- Harch, A -- Hart, H M -- Hersman, C B -- Hill, A -- Hill, M E -- Hinson, D P -- Holdridge, M E -- Horanyi, M -- Howard, A D -- Howett, C J A -- Jackman, C -- Jacobson, R A -- Jennings, D E -- Kammer, J A -- Kang, H K -- Kaufmann, D E -- Kollmann, P -- Krimigis, S M -- Kusnierkiewicz, D -- Lauer, T R -- Lee, J E -- Lindstrom, K L -- Linscott, I R -- Lisse, C M -- Lunsford, A W -- Mallder, V A -- Martin, N -- McComas, D J -- McNutt, R L Jr -- Mehoke, D -- Mehoke, T -- Melin, E D -- Mutchler, M -- Nelson, D -- Nimmo, F -- Nunez, J I -- Ocampo, A -- Owen, W M -- Paetzold, M -- Page, B -- Parker, A H -- Parker, J W -- Pelletier, F -- Peterson, J -- Pinkine, N -- Piquette, M -- Porter, S B -- Protopapa, S -- Redfern, J -- Reitsema, H J -- Reuter, D C -- Roberts, J H -- Robbins, S J -- Rogers, G -- Rose, D -- Runyon, K -- Retherford, K D -- Ryschkewitsch, M G -- Schenk, P -- Schindhelm, E -- Sepan, B -- Showalter, M R -- Singer, K N -- Soluri, M -- Stanbridge, D -- Steffl, A J -- Strobel, D F -- Stryk, T -- Summers, M E -- Szalay, J R -- Tapley, M -- Taylor, A -- Taylor, H -- Throop, H B -- Tsang, C C C -- Tyler, G L -- Umurhan, O M -- Verbiscer, A J -- Versteeg, M H -- Vincent, M -- Webbert, R -- Weidner, S -- Weigle, G E 2nd -- White, O L -- Whittenburg, K -- Williams, B G -- Williams, K -- Williams, S -- Woods, W W -- Zangari, A M -- Zirnstein, E -- New York, N.Y. -- Science. 2015 Oct 16;350(6258):aad1815. doi: 10.1126/science.aad1815.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Southwest Research Institute, Boulder, CO 80302, USA. astern@boulder.swri.edu. ; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA. ; National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA. ; Southwest Research Institute, San Antonio, TX 28510, USA. ; Lowell Observatory, Flagstaff, AZ 86001, USA. ; Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA. ; Southwest Research Institute, Boulder, CO 80302, USA. ; Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA. ; Universitat der Bundeswehr Munchen, Neubiberg 85577, Germany. ; Planetary Science Institute, Tucson, AZ 85719, USA. ; KinetX Aerospace, Tempe, AZ 85284, USA. ; NASA Jet Propulsion Laboratory, La Canada Flintridge, CA 91011, USA. ; Massachusetts Institute of Technology, Cambridge, MA 02139, USA. ; University of Bonn, Bonn D-53113, Germany. ; NASA Headquarters (retired), Washington, DC 20546, USA. ; University of Arizona, Tucson, AZ 85721, USA. ; Cornell University, Ithaca, NY 14853, USA. ; NASA Headquarters, Washington, DC 20546, USA. ; Rheinisches Institut fur Umweltforschung an der Universitat zu Koln, Cologne 50931, Germany. ; Department of Astronomy, University of Maryland, College Park, MD 20742, USA. ; Search for Extraterrestrial Intelligence Institute, Mountain View, CA 94043, USA. ; Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA. ; NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. ; National Optical Astronomy Observatory, Tucson, AZ 26732, USA. ; NASA Marshall Space Flight Center, Huntsville, AL 35812, USA. ; Stanford University, Stanford, CA 94305, USA. ; Space Telescope Science Institute, Baltimore, MD 21218, USA. ; University of California, Santa Cruz, CA 95064, USA. ; Lunar and Planetary Institute, Houston, TX 77058, USA. ; Michael Soluri Photography, New York, NY 10014, USA. ; Johns Hopkins University, Baltimore, MD 21218, USA. ; Roane State Community College, Jamestown, TN 38556, USA. ; George Mason University, Fairfax, VA 22030, USA. ; Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26472913" target="_blank"〉PubMed〈/a〉

Description: NASA's New Horizons spacecraft has revealed the complex geology of Pluto and Charon. Pluto's encounter hemisphere shows ongoing surface geological activity centered on a vast basin containing a thick layer of volatile ices that appears to be involved in convection and advection, with a crater retention age no greater than ~10 million years. Surrounding terrains show active glacial flow, apparent transport and rotation of large buoyant water-ice crustal blocks, and pitting, the latter likely caused by sublimation erosion and/or collapse. More enigmatic features include tall mounds with central depressions that are conceivably cryovolcanic and ridges with complex bladed textures. Pluto also has ancient cratered terrains up to ~4 billion years old that are extensionally faulted and extensively mantled and perhaps eroded by glacial or other processes. Charon does not appear to be currently active, but experienced major extensional tectonism and resurfacing (probably cryovolcanic) nearly 4 billion years ago. Impact crater populations on Pluto and Charon are not consistent with the steepest impactor size-frequency distributions proposed for the Kuiper belt.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Moore, Jeffrey M -- McKinnon, William B -- Spencer, John R -- Howard, Alan D -- Schenk, Paul M -- Beyer, Ross A -- Nimmo, Francis -- Singer, Kelsi N -- Umurhan, Orkan M -- White, Oliver L -- Stern, S Alan -- Ennico, Kimberly -- Olkin, Cathy B -- Weaver, Harold A -- Young, Leslie A -- Binzel, Richard P -- Buie, Marc W -- Buratti, Bonnie J -- Cheng, Andrew F -- Cruikshank, Dale P -- Grundy, Will M -- Linscott, Ivan R -- Reitsema, Harold J -- Reuter, Dennis C -- Showalter, Mark R -- Bray, Veronica J -- Chavez, Carrie L -- Howett, Carly J A -- Lauer, Tod R -- Lisse, Carey M -- Parker, Alex Harrison -- Porter, S B -- Robbins, Stuart J -- Runyon, Kirby -- Stryk, Ted -- Throop, Henry B -- Tsang, Constantine C C -- Verbiscer, Anne J -- Zangari, Amanda M -- Chaikin, Andrew L -- Wilhelms, Don E -- New Horizons Science Team -- New York, N.Y. -- Science. 2016 Mar 18;351(6279):1284-93. doi: 10.1126/science.aad7055.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA. jeff.moore@nasa.gov. ; Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA. ; Southwest Research Institute, Boulder, CO 80302, USA. ; Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA. ; Lunar and Planetary Institute, Houston, TX 77058, USA. ; The SETI Institute, Mountain View, CA 94043, USA. National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA. ; University of California, Santa Cruz, CA 95064, USA. ; National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA. ; Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA. ; Massachusetts Institute of Technology, Cambridge, MA 02139, USA. ; NASA Jet Propulsion Laboratory, Pasadena, CA 91019, USA. ; Lowell Observatory, Flagstaff, AZ 86001, USA. ; Stanford University, Stanford, CA 94305, USA. ; NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. ; The SETI Institute, Mountain View, CA 94043, USA. ; University of Arizona, Tucson, AZ 85721, USA. ; National Optical Astronomy Observatory, Tucson, AZ 85719, USA. ; Roane State Community College, Oak Ridge, TN 37830, USA. ; Planetary Science Institute, Tucson, AZ 85719, USA. ; Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA. ; Independent Science Writer, Arlington, VT 05250, USA. ; U.S. Geological Survey, Retired, Menlo Park, CA 94025, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26989245" target="_blank"〉PubMed〈/a〉

Description: Observations made during the New Horizons flyby provide a detailed snapshot of the current state of Pluto's atmosphere. Whereas the lower atmosphere (at altitudes of less than 200 kilometers) is consistent with ground-based stellar occultations, the upper atmosphere is much colder and more compact than indicated by pre-encounter models. Molecular nitrogen (N2) dominates the atmosphere (at altitudes of less than 1800 kilometers or so), whereas methane (CH4), acetylene (C2H2), ethylene (C2H4), and ethane (C2H6) are abundant minor species and likely feed the production of an extensive haze that encompasses Pluto. The cold upper atmosphere shuts off the anticipated enhanced-Jeans, hydrodynamic-like escape of Pluto's atmosphere to space. It is unclear whether the current state of Pluto's atmosphere is representative of its average state--over seasonal or geologic time scales.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gladstone, G Randall -- Stern, S Alan -- Ennico, Kimberly -- Olkin, Catherine B -- Weaver, Harold A -- Young, Leslie A -- Summers, Michael E -- Strobel, Darrell F -- Hinson, David P -- Kammer, Joshua A -- Parker, Alex H -- Steffl, Andrew J -- Linscott, Ivan R -- Parker, Joel Wm -- Cheng, Andrew F -- Slater, David C -- Versteeg, Maarten H -- Greathouse, Thomas K -- Retherford, Kurt D -- Throop, Henry -- Cunningham, Nathaniel J -- Woods, William W -- Singer, Kelsi N -- Tsang, Constantine C C -- Schindhelm, Eric -- Lisse, Carey M -- Wong, Michael L -- Yung, Yuk L -- Zhu, Xun -- Curdt, Werner -- Lavvas, Panayotis -- Young, Eliot F -- Tyler, G Leonard -- New Horizons Science Team -- New York, N.Y. -- Science. 2016 Mar 18;351(6279):aad8866. doi: 10.1126/science.aad8866.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Southwest Research Institute, San Antonio, TX 78238, USA. University of Texas at San Antonio, San Antonio, TX 78249, USA. rgladstone@swri.edu. ; Southwest Research Institute, Boulder, CO 80302, USA. ; National Aeronautics and Space Administration, Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA. ; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA. ; George Mason University, Fairfax, VA 22030, USA. ; The Johns Hopkins University, Baltimore, MD 21218, USA. ; Search for Extraterrestrial Intelligence Institute, Mountain View, CA 94043, USA. ; Stanford University, Stanford, CA 94305, USA. ; Southwest Research Institute, San Antonio, TX 78238, USA. ; Southwest Research Institute, San Antonio, TX 78238, USA. University of Texas at San Antonio, San Antonio, TX 78249, USA. ; Nebraska Wesleyan University, Lincoln, NE 68504, USA. ; California Institute of Technology, Pasadena, CA 91125, USA. ; Max-Planck-Institut fur Sonnensystemforschung, 37191 Katlenburg-Lindau, Germany. ; Groupe de Spectroscopie Moleculaire et Atmospherique, Universite Reims Champagne-Ardenne, 51687 Reims, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26989258" target="_blank"〉PubMed〈/a〉