Margaret Kivelson
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A Wunda-Full World? Carbon Dioxide Ice Deposits on Umbriel and Other Uranian Moons
Icarus 290 (2017) 1–13 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus A Wunda-full world? Carbon dioxide ice deposits on Umbriel and other Uranian moons ∗ Michael M. Sori , Jonathan Bapst, Ali M. Bramson, Shane Byrne, Margaret E. Landis Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA a r t i c l e i n f o a b s t r a c t Article history: Carbon dioxide has been detected on the trailing hemispheres of several Uranian satellites, but the exact Received 22 June 2016 nature and distribution of the molecules remain unknown. One such satellite, Umbriel, has a prominent Revised 28 January 2017 high albedo annulus-shaped feature within the 131-km-diameter impact crater Wunda. We hypothesize Accepted 28 February 2017 that this feature is a solid deposit of CO ice. We combine thermal and ballistic transport modeling to Available online 2 March 2017 2 study the evolution of CO 2 molecules on the surface of Umbriel, a high-obliquity ( ∼98 °) body. Consid- ering processes such as sublimation and Jeans escape, we find that CO 2 ice migrates to low latitudes on geologically short (100s–1000 s of years) timescales. Crater morphology and location create a local cold trap inside Wunda, and the slopes of crater walls and a central peak explain the deposit’s annular shape. The high albedo and thermal inertia of CO 2 ice relative to regolith allows deposits 15-m-thick or greater to be stable over the age of the solar system. -
Planetary Magnetospheres
CLBE001-ESS2E November 9, 2006 17:4 100-C 25-C 50-C 75-C C+M 50-C+M C+Y 50-C+Y M+Y 50-M+Y 100-M 25-M 50-M 75-M 100-Y 25-Y 50-Y 75-Y 100-K 25-K 25-19-19 50-K 50-40-40 75-K 75-64-64 Planetary Magnetospheres Margaret Galland Kivelson University of California Los Angeles, California Fran Bagenal University of Colorado, Boulder Boulder, Colorado CHAPTER 28 1. What is a Magnetosphere? 5. Dynamics 2. Types of Magnetospheres 6. Interaction with Moons 3. Planetary Magnetic Fields 7. Conclusions 4. Magnetospheric Plasmas 1. What is a Magnetosphere? planet’s magnetic field. Moreover, unmagnetized planets in the flowing solar wind carve out cavities whose properties The term magnetosphere was coined by T. Gold in 1959 are sufficiently similar to those of true magnetospheres to al- to describe the region above the ionosphere in which the low us to include them in this discussion. Moons embedded magnetic field of the Earth controls the motions of charged in the flowing plasma of a planetary magnetosphere create particles. The magnetic field traps low-energy plasma and interaction regions resembling those that surround unmag- forms the Van Allen belts, torus-shaped regions in which netized planets. If a moon is sufficiently strongly magne- high-energy ions and electrons (tens of keV and higher) tized, it may carve out a true magnetosphere completely drift around the Earth. The control of charged particles by contained within the magnetosphere of the planet. -
Planets Days Mini-Conference (Friday August 24)
Planets Days Mini-Conference (Friday August 24) Session I : 10:30 – 12:00 10:30 The Dawn Mission: Latest Results (Christopher Russell) 10:45 Revisiting the Oort Cloud in the Age of Large Sky Surveys (Julio Fernandez) 11:00 25 years of Adaptive Optics in Planetary Astronomy, from the Direct Imaging of Asteroids to Earth-Like Exoplanets (Franck Marchis) 11:15 Exploration of the Jupiter Trojans with the Lucy Mission (Keith Noll) 11:30 The New and Unexpected Venus from Akatsuki (Javier Peralta) 11:45 Exploration of Icy Moons as Habitats (Athena Coustenis) Session II: 13:30 – 15:00 13:30 Characterizing ExOPlanet Satellite (CHEOPS): ESA's first s-class science mission (Kate Isaak) 13:45 The Habitability of Exomoons (Christopher Taylor) 14:00 Modelling the Rotation of Icy Satellites with Application to Exoplanets (Gwenael Boue) 14:15 Novel Approaches to Exoplanet Life Detection: Disequilibrium Biosignatures and Their Detectability with the James Webb Space Telescope (Joshua Krissansen-Totton) 14:30 Getting to Know Sub-Saturns and Super-Earths: High-Resolution Spectroscopy of Transiting Exoplanets (Ray Jayawardhana) 14:45 How do External Giant Planets Influence the Evolution of Compact Multi-Planet Systems? (Dong Lai) Session III: 15:30 – 18:30 15:30 Titan’s Global Geology from Cassini (Rosaly Lopes) 15:45 The Origins Space Telescope and Solar System Science (James Bauer) 16:00 Relationship Between Stellar and Solar System Organics (Sun Kwok) 16:15 Mixing of Condensible Constituents with H/He During Formation of Giant Planets (Jack Lissauer) -
The Kepler Revolution Observations and Satellite Inferences of the Kepler Space Telescope Will Soon Run out of Fuel and End Its Mission
VOL. 99 • NO. 10 • OCT 2018 Models That Forecast Wildfires Recording the Roar of a Hurricane Earth & Space Science News How Much Snow Is in the World? The Honors and Recognition Committee is pleased to announce the recipients of this year’s Union Medals, Awards, and Prizes honors.agu.org Earth & Space Science News Contents OCTOBER 2018 PROJECT UPDATE VOLUME 99, ISSUE 10 20 Seismic Sensors Record a Hurricane’s Roar Newly installed infrasound sensors at a Global Seismographic Network station on Puerto Rico recorded the sounds of Hurricane Maria passing overhead. PROJECT UPDATE 26 How Can We Find Out How Much Snow Is in the World? In Colorado forests, NASA scientists and a multinational team of researchers test the limits of satellite remote sensing for measuring the water content of snow. 30 OPINION Global Water Clarity: COVER 14 Continuing a Century- Long Monitoring An approach that combines field The Kepler Revolution observations and satellite inferences of The Kepler Space Telescope will soon run out of fuel and end its mission. Here are nine Secchi depth could transform how we assess fundamental discoveries about planets aided by Kepler, one for each year since its water clarity across the globe and pinpoint launch. key changes over the past century. Earth & Space Science News Eos.org // 1 Contents DEPARTMENTS Senior Vice President, Marketing, Communications, and Digital Media Dana Davis Rehm: AGU, Washington, D. C., USA; [email protected] Editors Christina M. S. Cohen Wendy S. Gordon Carol A. Stein California Institute Ecologia Consulting, Department of Earth and of Technology, Pasadena, Austin, Texas, USA; Environmental Sciences, Calif., USA; wendy@ecologiaconsulting University of Illinois at cohen@srl .caltech.edu .com Chicago, Chicago, Ill., José D. -
Does Enceladus Govern Magnetospheric Dynamics at Saturn?
SPECIALSECTION evidence for plate tectonics? Where are the References and Notes E. D. Miner, M. S. Matthews, Eds. (Univ. of Arizona Press, plumes_ vents, where are the plumes_ sources 1. C. C. Porco et al., Science 311, 1393 (2006). Tucson, 1991), p. 410. 18. J. S. Kargel, S. Pozio, Icarus 119, 385 (1996). in the interior, and how are they driven? Does 2. C. J. Hansen et al., Science 311, 1422 (2006). 3. F. Spahn et al., Science 311, 1416 (2006). 19. B. A. Smith et al., Science 215, 504 (1982). Enceladus host hydrated salts or acids, such as 4. J. H. Waite Jr. et al., Science 311, 1419 (2006). 20. J. B. Plescia, J. M. Boyce, Nature 301, 666 (1983). those found on Europa (15, 16)? Where is the 5. J. R. Spencer et al., Science 311, 1401 (2006). 21. S. W. Squyres, R. T. Reynolds, P. M. Cassen, Icarus 53, 319 ammonia, or is it truly absent? Is there a briny 6. R. H. Brown et al., Science 311, 1425 (2006). (1983). 22. R. G. Ross, J. S. Kargel, in Solar System Ices, C. de Bergh, _ 7. M. K. Dougherty, Science 311, 1406 (2006). ocean, such as Europa s and other Galilean M. Festou, B. Schmitt, Eds. (Kluwer, Dordrecht, 8. G. H. Jones et al., Science 311, 1412 (2006). satellites_ (13–15)? Netherlands, 1998), p. 33. 9. R. L. Tokar et al., Science 311, 1409 (2006). If a wet domain exists at the bottom of 23. O. Prieto, J. S. Kargel, Lunar Planet. Sci. XXXIII, abstract 10. -
Discover NASA
SPACE SCIENCE INSTITUTE NEWSLETTER WINTER 2016 W Space Science Institute Newsletter THE CARINA NEBULA IMAGE CREDIT: NASA, ESA/ STSCI IN THIS ISSUE NCIL News… Big News in Astronomy Conference Highlights: Clouds Over Martian DPS, AGU and AAS Low Latitudes! By Dr. Karly Pitman, Executive Director Submitted by Dr. Todd Clancy – SSI NC While the rest of the world is Over the past two slowing down around the holidays, decades, the our scientists kick into high gear in importance of the winter months submitting grant clouds in Mars’ proposals, judging others’ proposals atmosphere has at review panels, and traveling to been established present results at national and through new More on Page 6… international conferences. This year, observations and Cassini Completes Final Close conference season kicked off with the modeling. A Enceladus Flyby! American Astronomical Society’s variety of cloud Division for Planetary Sciences forms reflects the (DPS) held Nov. 8-13, 2015 at the variety in Gaylord National Resort and saturation Figure 1. CRISM color Convention Center in National conditions (e.g. limb image of CO2 Harbor, MD. More on Page 10 atmospheric clouds – credit page 3. temperatures) and dynamical forcing ranging from local to global conditions. This range of behaviors spans narrow vertical pipes of uplift that force high altitude More on Page 2… perihelion (nearest to the Sun) cloud trails in the warm orbital phase of the Covering science news around Mars atmosphere, to the global low Boulder! latitude gird of the aphelion (farthest More on Page 5… from the Sun) cloud belt in the cold orbital phase of the Mars atmosphere. -
A Study of the Structure and Dynamics of Saturn's Inner Plasma Disk
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1298 A study of the structure and dynamics of Saturn's inner plasma disk MIKA HOLMBERG ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 ISBN 978-91-554-9353-0 UPPSALA urn:nbn:se:uu:diva-263278 2015 Dissertation presented at Uppsala University to be publicly examined in Lägerhyddsvägen 1, Uppsala, Thursday, 19 November 2015 at 13:00 for the degree of Doctor of Philosophy. The examination will be conducted in English. Faculty examiner: Professor Thomas Cravens (University of Kansas). Abstract Holmberg, M. 2015. A study of the structure and dynamics of Saturn's inner plasma disk. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1298. 53 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9353-0. This thesis presents a study of the inner plasma disk of Saturn. The results are derived from measurements by the instruments on board the Cassini spacecraft, mainly the Cassini Langmuir probe (LP), which has been in orbit around Saturn since 2004. One of the great discoveries of the Cassini spacecraft is that the Saturnian moon Enceladus, located at 3.95 Saturn radii (1 RS = 60,268 km), constantly expels water vapor and condensed water from ridges and troughs located in its south polar region. Impact ionization and photoionization of the water molecules, and subsequent transport, creates a plasma disk around the orbit of Enceladus. The plasma disk ion + + + + + + components are mainly hydrogen ions H and water group ions W (O , OH , H2O , and H3O ). The Cassini LP is used to measure the properties of the plasma. -
Perfect Little Planet Educator's Guide
Educator’s Guide Perfect Little Planet Educator’s Guide Table of Contents Vocabulary List 3 Activities for the Imagination 4 Word Search 5 Two Astronomy Games 7 A Toilet Paper Solar System Scale Model 11 The Scale of the Solar System 13 Solar System Models in Dough 15 Solar System Fact Sheet 17 2 “Perfect Little Planet” Vocabulary List Solar System Planet Asteroid Moon Comet Dwarf Planet Gas Giant "Rocky Midgets" (Terrestrial Planets) Sun Star Impact Orbit Planetary Rings Atmosphere Volcano Great Red Spot Olympus Mons Mariner Valley Acid Solar Prominence Solar Flare Ocean Earthquake Continent Plants and Animals Humans 3 Activities for the Imagination The objectives of these activities are: to learn about Earth and other planets, use language and art skills, en- courage use of libraries, and help develop creativity. The scientific accuracy of the creations may not be as im- portant as the learning, reasoning, and imagination used to construct each invention. Invent a Planet: Students may create (draw, paint, montage, build from household or classroom items, what- ever!) a planet. Does it have air? What color is its sky? Does it have ground? What is its ground made of? What is it like on this world? Invent an Alien: Students may create (draw, paint, montage, build from household items, etc.) an alien. To be fair to the alien, they should be sure to provide a way for the alien to get food (what is that food?), a way to breathe (if it needs to), ways to sense the environment, and perhaps a way to move around its planet. -
Mason Elected As President of Hoffman Club Council May Discuss
FACTS 10,000 WITHOUT FEAR READERS OR FAVOR EVERY WEEK Vol. 56. No. 15 SOUTH AMBOY, N. J., FRIDAY, MAY 14, 1937 Price Four Cents Local Woman On Official Board DISABLED WAR Police Ordinance Not Likely To Get Mason Elected Of Middlesex Young Democrats VETERANS POST Enough Votes For Passage Tuesday Council May The annual election of officers of South Plainfleld, sergeant at arms; There is little likelihood that Or- uncertain terms. Several conferenc- the Young Democrats of Middlesex Henry Handleman, Dunellen, solici- ELECTS OFFICERS dinance No. 387 amending the pre- es on the matter have been held and As President of tor; Edward Johns, Middlesex Boro, , _JU_ 'sent police ordinance to add four a decision to drop the matter for the Discuss WPA County was held in the City Hall In state committeeman, Charles Sulli- Theodore. DifFenbacher Elected ^members and take the jurisdiction present because of the objections New Brunswick Tuesday evening at van, East Brunswick, alternate; Aim Commander of Lt. Thomas over tlie force out of the hands of which have been raised against it, which time Edward J. Harkins of Biler, New Brunswick, alternate Kerr Chapter the Council and place it in the hands has been reached. Hoffman Club New Brunswick was elected presi- state eommitteewoman; James Doy- of the Mayor, will ever be passed. It has also been learned that the Work Tonight dent. South Amboy was given recog- le, Piscataway, trustee, 3 years; Ed- The installation of officers of Lt. Since the ordinance was introduc- ordinance will no doubt be presented ward Cahill, Monrrtouth Junction, Thomas Kerr Chapter of the Disab- As the result of his election as nition in the designation of Dorothy ed at first reading when the Coun- to the council for consideration at A busy meeting is forecasted for Dwyer as state committeewoman. -
Apollo 11 Goodwill Messages
FOR RELEASE: SUNDAY July 13, 1969 RELEASE NO: 69-83F . .. -. I. APOLLO 11 GOODWILL MESSAGES A small disc carrying statements by Presidents Eisenhower, Kennedy,. Johnson and Nixon and messages of goodwill from lead- ers of 73 countries around the world will be left on the Moon by the Apollo 11 astronauts. The disc also carries a listing of the leadership of the Congress and a listing of members of the four committees of the House and Senate responsible for the National Aeronautics and . Space Administration legislation. Additionally, the names of NASA's top management, including past Administrators and Deputy Administrators, and the present NASA management are included. These include NASA's first Administrator, Dr. T. Keith Glennan; its long-time Deputy Administrator, the late Dr. Hugh L. Dryden; former Administr>ator James E. Webb; and former Deputy Administrator, Dr. Robert C. Seamans, Jr., present Secretary of the Air Force. -more- 7/11/69 -%? ,,, , , . -2- Dr. Thomas 0 Paine is the present NASA Administrator. The disc, about the size of a 50-cent piece, is made of silicon -- ,a non-metallic chemical element found abundantly in nature and used widely im modern electronics. Through a process used to make microminiature electronic circuits, the statements, the messages, and names were etched (sn the grey-colored disc. Each message was reduced 200 times to a size rnuch smaller than the head of a !)in (0.0425 x 0.055 inches) and appears on the disc as a barely visible dot. NASA':; Electronics Research Center at Cambridge, Mass., was assisted by the Sprague Electric Company's Serci-Conductor Division, Worcester, Mass., in preparing the historic disc. -
Asteroid Resource Utilization: Ethical Concerns and Progress
Asteroid Resource Utilization: Ethical Concerns and Progress Lead Author: Andrew S. Rivkin (Johns Hopkins University Applied Physics Laboratory, [email protected]) Co-authors: Moses Milazzo (Other Orb LLC; He/Him/His), Aparna Venkatesan (University of San Francisco), Elizabeth Frank (First Mode), Monica R. Vidaurri (Howard University/NASA Goddard Space Flight Center), Phil Metzger (Florida Space Institute/University of Central Florida), Chris Lewicki (Former CEO, Planetary Resources) Co-signers: Barbara Cohen (NASA GSFC), Parvathy Prem (Johns Hopkins University Applied Physics Laboratory), Mark Gurwell (Center for Astrophysics | Harvard & Smithsonian), Cosette Gilmour (York University), Michael C. Nolan (University of Arizona), Divya M. Persaud (UCL), Alessondra Springmann (University of Arizona), Margaret Landis (University of Colorado, Boulder/LASP), Flaviane C. F. Venditti (Arecibo Observatory/UCF, Michele T. Bannister (University of Canterbury, NZ), M. M. McAdam (NASA Ames Research Center), Jennifer (JA) Grier (Planetary Science Institute), Katelyn Frizzell (Rutgers University), Alexandra Warren (University of Chicago), Amanda A. Sickafoose (Planetary Science Institute), Theodore Kareta (University of Arizona), Jamie Molaro (Planetary Science Institute), Anthony Hennig (George Washington University), Angela Stickle (Johns Hopkins University Applied Physics Laboratory) 350-character abstract: As asteroid mining moves toward reality, the high bar to entering the business may limit participation and increase inequality, reducing or eliminating any benefit gained by marginalized people or developing nations. Consideration of ethical issues is urgently needed, as well as participation in international, not merely multilateral, solutions. Executive Summary The past decade has seen asteroid mining move from a science-fiction topic to a near-term likelihood. Several asteroid mining companies were founded in the last decade and developed candidate business cases. -
Irregular Satellites of the Giant Planets 411
Nicholson et al.: Irregular Satellites of the Giant Planets 411 Irregular Satellites of the Giant Planets Philip D. Nicholson Cornell University Matija Cuk University of British Columbia Scott S. Sheppard Carnegie Institution of Washington David Nesvorný Southwest Research Institute Torrence V. Johnson Jet Propulsion Laboratory The irregular satellites of the outer planets, whose population now numbers over 100, are likely to have been captured from heliocentric orbit during the early period of solar system history. They may thus constitute an intact sample of the planetesimals that accreted to form the cores of the jovian planets. Ranging in diameter from ~2 km to over 300 km, these bodies overlap the lower end of the presently known population of transneptunian objects (TNOs). Their size distributions, however, appear to be significantly shallower than that of TNOs of comparable size, suggesting either collisional evolution or a size-dependent capture probability. Several tight orbital groupings at Jupiter, supported by similarities in color, attest to a common origin followed by collisional disruption, akin to that of asteroid families. But with the limited data available to date, this does not appear to be the case at Uranus or Neptune, while the situa- tion at Saturn is unclear. Very limited spectral evidence suggests an origin of the jovian irregu- lars in the outer asteroid belt, but Saturn’s Phoebe and Neptune’s Nereid have surfaces domi- nated by water ice, suggesting an outer solar system origin. The short-term dynamics of many of the irregular satellites are dominated by large-amplitude coupled oscillations in eccentricity and inclination and offer several novel features, including secular resonances.