ALBERT

Description: Cities and their transportation systems become increasingly complex and multimodal as they grow, and it is natural to wonder whether it is possible to quantitatively characterize our difficulty navigating in them and whether such navigation exceeds our cognitive limits. A transition between different search strategies for navigating in metropolitan maps has been observed for large, complex metropolitan networks. This evidence suggests the existence of a limit associated with cognitive overload and caused by a large amount of information that needs to be processed. In this light, we analyzed the world’s 15 largest metropolitan networks and estimated the information limit for determining a trip in a transportation system to be on the order of 8 bits. Similar to the "Dunbar number," which represents a limit to the size of an individual’s friendship circle, our cognitive limit suggests that maps should not consist of more than 250 connection points to be easily readable. We also show that including connections with other transportation modes dramatically increases the information needed to navigate in multilayer transportation networks. In large cities such as New York, Paris, and Tokyo, more than 80% of the trips are above the 8-bit limit. Multimodal transportation systems in large cities have thus already exceeded human cognitive limits and, consequently, the traditional view of navigation in cities has to be revised substantially.

Description: 〈p〉Imaging charge, spin, and energy flow in materials is a current grand challenge that is relevant to a host of nanoenhanced systems, including thermoelectric, photovoltaic, electronic, and spin devices. Ultrafast coherent x-ray sources enable functional imaging on nanometer length and femtosecond timescales particularly when combined with advances in coherent imaging techniques. Here, we combine ptychographic coherent diffractive imaging with an extreme ultraviolet high harmonic light source to directly visualize the complex thermal and acoustic response of an individual nanoscale antenna after impulsive heating by a femtosecond laser. We directly image the deformations induced in both the nickel tapered nanoantenna and the silicon substrate and see the lowest-order generalized Lamb wave that is partially confined to a uniform nanoantenna. The resolution achieved—sub–100 nm transverse and 0.5-Å axial spatial resolution, combined with 10-fs temporal resolution—represents a significant advance in full-field dynamic imaging capabilities. The tapered nanoantenna is sufficiently complex that a full simulation of the dynamic response would require enormous computational power. We therefore use our data to benchmark approximate models and achieve excellent agreement between theory and experiment. In the future, this work will enable three-dimensional functional imaging of opaque materials and nanostructures that are sufficiently complex that their functional properties cannot be predicted.〈/p〉

Description: Imaging charge, spin, and energy flow in materials is a current grand challenge that is relevant to a host of nanoenhanced systems, including thermoelectric, photovoltaic, electronic, and spin devices. Ultrafast coherent x-ray sources enable functional imaging on nanometer length and femtosecond timescales particularly when combined with advances in coherent imaging techniques. Here, we combine ptychographic coherent diffractive imaging with an extreme ultraviolet high harmonic light source to directly visualize the complex thermal and acoustic response of an individual nanoscale antenna after impulsive heating by a femtosecond laser. We directly image the deformations induced in both the nickel tapered nanoantenna and the silicon substrate and see the lowest-order generalized Lamb wave that is partially confined to a uniform nanoantenna. The resolution achieved—sub–100 nm transverse and 0.5-Å axial spatial resolution, combined with 10-fs temporal resolution—represents a significant advance in full-field dynamic imaging capabilities. The tapered nanoantenna is sufficiently complex that a full simulation of the dynamic response would require enormous computational power. We therefore use our data to benchmark approximate models and achieve excellent agreement between theory and experiment. In the future, this work will enable three-dimensional functional imaging of opaque materials and nanostructures that are sufficiently complex that their functional properties cannot be predicted.

Description: The light emitted by all galaxies over the history of the Universe produces the extragalactic background light (EBL) at ultraviolet, optical, and infrared wavelengths. The EBL is a source of opacity for gamma rays via photon-photon interactions, leaving an imprint in the spectra of distant gamma-ray sources. We measured this attenuation using 739 active galaxies and one gamma-ray burst detected by the Fermi Large Area Telescope. This allowed us to reconstruct the evolution of the EBL and determine the star formation history of the Universe over 90% of cosmic time. Our star formation history is consistent with independent measurements from galaxy surveys, peaking at redshift z ~ 2. Upper limits of the EBL at the epoch of reionization suggest a turnover in the abundance of faint galaxies at z ~ 6.

Description: Congenital heart disease (CHD) patients have an increased prevalence of extracardiac congenital anomalies (CAs) and risk of neurodevelopmental disabilities (NDDs). Exome sequencing of 1213 CHD parent-offspring trios identified an excess of protein-damaging de novo mutations, especially in genes highly expressed in the developing heart and brain. These mutations accounted for 20% of patients with CHD, NDD, and CA but only 2% of patients with isolated CHD. Mutations altered genes involved in morphogenesis, chromatin modification, and transcriptional regulation, including multiple mutations in RBFOX2, a regulator of mRNA splicing. Genes mutated in other cohorts examined for NDD were enriched in CHD cases, particularly those with coexisting NDD. These findings reveal shared genetic contributions to CHD, NDD, and CA and provide opportunities for improved prognostic assessment and early therapeutic intervention in CHD patients.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Homsy, Jason -- Zaidi, Samir -- Shen, Yufeng -- Ware, James S -- Samocha, Kaitlin E -- Karczewski, Konrad J -- DePalma, Steven R -- McKean, David -- Wakimoto, Hiroko -- Gorham, Josh -- Jin, Sheng Chih -- Deanfield, John -- Giardini, Alessandro -- Porter, George A Jr -- Kim, Richard -- Bilguvar, Kaya -- Lopez-Giraldez, Francesc -- Tikhonova, Irina -- Mane, Shrikant -- Romano-Adesman, Angela -- Qi, Hongjian -- Vardarajan, Badri -- Ma, Lijiang -- Daly, Mark -- Roberts, Amy E -- Russell, Mark W -- Mital, Seema -- Newburger, Jane W -- Gaynor, J William -- Breitbart, Roger E -- Iossifov, Ivan -- Ronemus, Michael -- Sanders, Stephan J -- Kaltman, Jonathan R -- Seidman, Jonathan G -- Brueckner, Martina -- Gelb, Bruce D -- Goldmuntz, Elizabeth -- Lifton, Richard P -- Seidman, Christine E -- Chung, Wendy K -- T32 HL007208/HL/NHLBI NIH HHS/ -- Arthritis Research UK/United Kingdom -- British Heart Foundation/United Kingdom -- Department of Health/United Kingdom -- Howard Hughes Medical Institute/ -- Wellcome Trust/United Kingdom -- New York, N.Y. -- Science. 2015 Dec 4;350(6265):1262-6. doi: 10.1126/science.aac9396.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Genetics, Harvard Medical School, Boston, MA, USA. Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, USA. ; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA. ; Departments of Systems Biology and Biomedical Informatics, Columbia University Medical Center, New York, NY, USA. ; Department of Genetics, Harvard Medical School, Boston, MA, USA. NIHR Cardiovascular Biomedical Research Unit at Royal Brompton & Harefield NHS Foundation and Trust and Imperial College London, London, UK. National Heart & Lung Institute, Imperial College London, London, UK. ; Department of Genetics, Harvard Medical School, Boston, MA, USA. Analytical and Translational Genetics Unit, Massachusetts General Hospital and Harvard Medical School, Boston MA, USA. ; Department of Genetics, Harvard Medical School, Boston, MA, USA. Howard Hughes Medical Institute, Harvard University, Boston, MA, USA. ; Department of Genetics, Harvard Medical School, Boston, MA, USA. ; Department of Cardiology, University College London and Great Ormond Street Hospital, London, UK. ; Department of Pediatrics, University of Rochester Medical Center, The School of Medicine and Dentistry, Rochester, NY, USA. ; Section of Cardiothoracic Surgery, University of Southern California Keck School of Medicine, Los Angeles, CA, USA. ; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA. Yale Center for Genome Analysis, Yale University, New Haven, CT, USA. ; Yale Center for Genome Analysis, Yale University, New Haven, CT, USA. ; Steven and Alexandra Cohen Children's Medical Center of New York, New Hyde Park, NY, USA. ; Departments of Systems Biology and Biomedical Informatics, Columbia University Medical Center, New York, NY, USA. Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA. ; Department of Neurology, Columbia University Medical Center, New York, NY, USA. ; Department of Pediatrics, Columbia University Medical Center, New York, NY, USA. ; Department of Cardiology, Children's Hospital Boston, Boston, MA, USA. ; Division of Pediatric Cardiology, University of Michigan, Ann Arbor, MI, USA. ; Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. ; Department of Cardiology, Boston Children's Hospital, Boston, MA, USA. ; Department of Pediatric Cardiac Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA, USA. ; Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. ; Department of Psychiatry, University of California San Francisco, San Francisco, CA, USA. ; Heart Development and Structural Diseases Branch, Division of Cardiovascular Sciences, NHLBI/NIH, Bethesda, MD, USA. ; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA. bruce.gelb@mssm.edu goldmuntz@email.chop.edu martina.brueckner@yale.edu richard.lifton@yale.edu cseidman@genetics.med.harvard.edu wkc15@cumc.columbia.edu. ; Mindich Child Health and Development Institute and Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA. bruce.gelb@mssm.edu goldmuntz@email.chop.edu martina.brueckner@yale.edu richard.lifton@yale.edu cseidman@genetics.med.harvard.edu wkc15@cumc.columbia.edu. ; Department of Pediatrics, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA. bruce.gelb@mssm.edu goldmuntz@email.chop.edu martina.brueckner@yale.edu richard.lifton@yale.edu cseidman@genetics.med.harvard.edu wkc15@cumc.columbia.edu. ; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA. Howard Hughes Medical Institute, Yale University, New Haven, CT, USA. bruce.gelb@mssm.edu goldmuntz@email.chop.edu martina.brueckner@yale.edu richard.lifton@yale.edu cseidman@genetics.med.harvard.edu wkc15@cumc.columbia.edu. ; Department of Genetics, Harvard Medical School, Boston, MA, USA. Howard Hughes Medical Institute, Harvard University, Boston, MA, USA. Cardiovascular Division, Brigham & Women's Hospital, Harvard University, Boston, MA, USA. bruce.gelb@mssm.edu goldmuntz@email.chop.edu martina.brueckner@yale.edu richard.lifton@yale.edu cseidman@genetics.med.harvard.edu wkc15@cumc.columbia.edu. ; Departments of Pediatrics and Medicine, Columbia University Medical Center, New York, NY, USA. bruce.gelb@mssm.edu goldmuntz@email.chop.edu martina.brueckner@yale.edu richard.lifton@yale.edu cseidman@genetics.med.harvard.edu wkc15@cumc.columbia.edu.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26785492" target="_blank"〉PubMed〈/a〉

Description: Whereas the predominant shapes of most animal tails are cylindrical, seahorse tails are square prisms. Seahorses use their tails as flexible grasping appendages, in spite of a rigid bony armor that fully encases their bodies. We explore the mechanics of two three-dimensional-printed models that mimic either the natural (square prism) or hypothetical (cylindrical) architecture of a seahorse tail to uncover whether or not the square geometry provides any functional advantages. Our results show that the square prism is more resilient when crushed and provides a mechanism for preserving articulatory organization upon extensive bending and twisting, as compared with its cylindrical counterpart. Thus, the square architecture is better than the circular one in the context of two integrated functions: grasping ability and crushing resistance.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Porter, Michael M -- Adriaens, Dominique -- Hatton, Ross L -- Meyers, Marc A -- McKittrick, Joanna -- New York, N.Y. -- Science. 2015 Jul 3;349(6243):aaa6683. doi: 10.1126/science.aaa6683. Epub 2015 Jul 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Mechanical Engineering, Clemson University, Clemson, SC 29634, USA. mmporte@clemson.edu. ; Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium. ; School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, OR 97330, USA. ; Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093, USA. Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093, USA. Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA. ; Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093, USA. Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26138983" 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: 5-Methylthioadenosine phosphorylase (MTAP) is a key enzyme in the methionine salvage pathway. The MTAP gene is frequently deleted in human cancers because of its chromosomal proximity to the tumor suppressor gene CDKN2A. By interrogating data from a large-scale short hairpin RNA-mediated screen across 390 cancer cell line models, we found that the viability of MTAP-deficient cancer cells is impaired by depletion of the protein arginine methyltransferase PRMT5. MTAP-deleted cells accumulate the metabolite methylthioadenosine (MTA), which we found to inhibit PRMT5 methyltransferase activity. Deletion of MTAP in MTAP-proficient cells rendered them sensitive to PRMT5 depletion. Conversely, reconstitution of MTAP in an MTAP-deficient cell line rescued PRMT5 dependence. Thus, MTA accumulation in MTAP-deleted cancers creates a hypomorphic PRMT5 state that is selectively sensitized toward further PRMT5 inhibition. Inhibitors of PRMT5 that leverage this dysregulated metabolic state merit further investigation as a potential therapy for MTAP/CDKN2A-deleted tumors.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mavrakis, Konstantinos J -- McDonald, E Robert 3rd -- Schlabach, Michael R -- Billy, Eric -- Hoffman, Gregory R -- deWeck, Antoine -- Ruddy, David A -- Venkatesan, Kavitha -- Yu, Jianjun -- McAllister, Gregg -- Stump, Mark -- deBeaumont, Rosalie -- Ho, Samuel -- Yue, Yingzi -- Liu, Yue -- Yan-Neale, Yan -- Yang, Guizhi -- Lin, Fallon -- Yin, Hong -- Gao, Hui -- Kipp, D Randal -- Zhao, Songping -- McNamara, Joshua T -- Sprague, Elizabeth R -- Zheng, Bing -- Lin, Ying -- Cho, Young Shin -- Gu, Justin -- Crawford, Kenneth -- Ciccone, David -- Vitari, Alberto C -- Lai, Albert -- Capka, Vladimir -- Hurov, Kristen -- Porter, Jeffery A -- Tallarico, John -- Mickanin, Craig -- Lees, Emma -- Pagliarini, Raymond -- Keen, Nicholas -- Schmelzle, Tobias -- Hofmann, Francesco -- Stegmeier, Frank -- Sellers, William R -- New York, N.Y. -- Science. 2016 Mar 11;351(6278):1208-13. doi: 10.1126/science.aad5944. Epub 2016 Feb 11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA. ; Novartis Institutes for Biomedical Research, Basel CH-4002, Switzerland. ; Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA. ; China Novartis Institutes for Biomedical Research, Shanghai 201203, China. ; Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA. william.sellers@novartis.com fstegmeier@ksqtx.com.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26912361" 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: The New Horizons mission has provided resolved measurements of Pluto's moons Styx, Nix, Kerberos, and Hydra. All four are small, with equivalent spherical diameters of ~40 kilometers for Nix and Hydra and ~10 kilometers for Styx and Kerberos. They are also highly elongated, with maximum to minimum axis ratios of ~2. All four moons have high albedos (~50 to 90%) suggestive of a water-ice surface composition. Crater densities on Nix and Hydra imply surface ages of at least 4 billion years. The small moons rotate much faster than synchronous, with rotational poles clustered nearly orthogonal to the common pole directions of Pluto and Charon. These results reinforce the hypothesis that the small moons formed in the aftermath of a collision that produced the Pluto-Charon binary.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Weaver, H A -- Buie, M W -- Buratti, B J -- Grundy, W M -- Lauer, T R -- Olkin, C B -- Parker, A H -- Porter, S B -- Showalter, M R -- Spencer, J R -- Stern, S A -- Verbiscer, A J -- McKinnon, W B -- Moore, J M -- Robbins, S J -- Schenk, P -- Singer, K N -- Barnouin, O S -- Cheng, A F -- Ernst, C M -- Lisse, C M -- Jennings, D E -- Lunsford, A W -- Reuter, D C -- Hamilton, D P -- Kaufmann, D E -- Ennico, K -- Young, L A -- Beyer, R A -- Binzel, R P -- Bray, V J -- Chaikin, A L -- Cook, J C -- Cruikshank, D P -- Dalle Ore, C M -- Earle, A M -- Gladstone, G R -- Howett, C J A -- Linscott, I R -- Nimmo, F -- Parker, J Wm -- Philippe, S -- Protopapa, S -- Reitsema, H J -- Schmitt, B -- Stryk, T -- Summers, M E -- Tsang, C C C -- Throop, H H B -- White, O L -- Zangari, A M -- New York, N.Y. -- Science. 2016 Mar 18;351(6279):aae0030. doi: 10.1126/science.aae0030.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA. hal.weaver@jhuapl.edu. ; Southwest Research Institute, Boulder, CO 80302, USA. ; NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. ; Lowell Observatory, Flagstaff, AZ 86001, USA. ; National Optical Astronomy Observatory, Tucson, AZ 26732, USA. ; SETI Institute, Mountain View, CA 94043, USA. ; Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA. ; Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA. ; Space Science Division, NASA Ames Research Center, Moffett Field, CA 94035, USA. ; Lunar and Planetary Institute, Houston, TX 77058, USA. ; Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA. ; NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. ; Department of Astronomy, University of Maryland, College Park, MD 20742, USA. ; SETI Institute, Mountain View, CA 94043, USA. Space Science Division, NASA Ames Research Center, Moffett Field, CA 94035, USA. ; Massachusetts Institute of Technology, Cambridge, MA 02139, USA. ; University of Arizona, Tucson, AZ 85721, USA. ; Independent science writer, Arlington, VT, USA. ; Southwest Research Institute, San Antonio, TX 78238, USA. ; Stanford University, Stanford, CA 94305, USA. ; University of California, Santa Cruz, CA 95064, USA. ; Universite Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France. ; Roane State Community College, Oak Ridge, TN 37830, USA. ; George Mason University, Fairfax, VA 22030, USA. ; Planetary Science Institute, Tucson, AZ 85719, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26989256" target="_blank"〉PubMed〈/a〉