DOCSLIB.ORG

In Situ Probes in the Atmospheres of the Ice Giants

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
In Situ Probes in the Atmospheres of the Ice Giants In Situ Probes in the Atmospheres of the Ice Giants Principal Author: Glenn Orton Jet Propulsion Laboratory, California Institute of Technology Pasadena, California 91109, USA ([email protected]) Co-Authors: David Atkinson1, Tibor Balint1, Mark Hofstadter1, Olivier Mousis2, Kunio Sayanagi3, Tom Spilker4 1JPL/Caltech, USA, 2Aix-Marseille Univ., France, 3Hampton Univ. USA, 4Independent consultant, USA Jet Propulsion Laboratory, California Institute of Technology Pasadena, California 91109, USA Abstract This paper describes atmospheric entry and descent probe missions in the atmospheres of the ice giants, Uranus and Neptune, targeting a minimum depth at the 10-bar level. In situ exploration of ice giant atmospheres addresses two broad themes: i) the formation history of the ice-giant planets and their role in the evolution of the solar system, and ii) the structure, dynamics, and processes in their atmospheres. An ice giant probe descending under parachute can measure abundances of key atmospheric constituents, deep thermal structure, dynamics, and processes, with data returned to Earth by a Carrier Relay Spacecraft. An atmospheric probe is an essential element of a possible future NASA Ice Giant New Frontier or Flagship mission. 1. Introduction The gas giant planets, Jupiter and Saturn, and the ice giant planets, Uranus and Neptune, contain most of the non-solar mass of the solar system and have played a significant role in shaping solar system evolution [1], influencing its current structure and affecting delivery of volatiles to the inner (terrestrial) planets [2]. Understanding the formation, evolution, and ultimate location of the giant planets is key to understanding the formation and evolution of the solar system as a whole. To extend knowledge and add additional clarity to the role played by the giant planets in solar system formation and evolution requires in situ exploration of the gas and ice giant planets. In particular, noble gases reflect both the location and processes of giant planet formation and subsequent evolution. Additionally, processes in ice giant atmospheres differ significantly from processes in the atmospheres of the gas giant planets. A key example is the predominance of retrograde rather than prograde winds at low latitudes, and the structure, location, and properties of condensate clouds in the significantly colder atmospheres found in the outer solar system. Although remote sensing is capable of making many important measurements of the composition of and processes within planetary atmospheres, remote sensing has limited capabilities to observe the deeper atmosphere beneath the clouds [3]. Atmospheric measurements beyond the reach of remote sensing require entry and descent probes to determine key atmospheric constituents including the abundance of noble gases and isotopes as well as the structure of and processes within the atmosphere beneath the cloud tops. Measurements of noble gas abundances and the ratio of key isotopes must be made in situ by a probe carrying a mass spectrometer, possibly including a tunable laser spectrometer and a dedicated helium abundance detector. Since noble gases are expected to be well-mixed, abundance measurements can be made by a relatively shallow probe in the upper atmosphere. Measurements of cloud condensates and condensables requires a vertical profile by a probe descending into the deeper atmosphere, down to 10 bars of pressure or more. Atmospheric processes including dynamics requires the descent probe to carry an atmospheric structure instrument with sensors for pressure and temperature, electrical properties, as well as an atmospheric acoustic properties to measure speed of sound from which the atmospheric ortho-para H2 ratio can be found. Other atmospheric processes including the net radiative flux transfer profile of the atmosphere and cloud location, composition, structure, and aerosol properties such as size, number density, and shape requires additional in situ instrumentation. Two themes define the science motivation and instrument requirements for in situ exploration of ice giant atmospheres: i) the formation history of the ice giant planets and the role of the ice giants in the evolution of the solar system, and ii) the structure, dynamics, and processes in ice giant atmospheres (Table 1). The details of these goals can be found in our companion white paper [4]. 1 Table 1. Notional Ice Giant Probe Science Traceability Matrix Science Measurement Example Comments/Notes Science Goals Objectives Requirements Instruments He/H : ±2% Well-mixed H S, H O, Determine well- 2 2 2 Ne/H, Ar/H, Kr/H, S, O isotopes, NH Understand the mixed atmos- 3 Xe/H: ±10% requires deep probe. formation of the pheric composi- C/H, N/H, S/H, P/H: RSE Atmospheric Ice Giant tion including ±10% MS/TLS absorption for profile Planets and their abundances 15N/14N, D/H: ±5% RSE/AtmAbs of microwave absor- role in the (relative to H) of 3He/4He: ±3% bers (NH and H S); evolution of the He, noble gases, 3 2 Ne, Ar, Kr, Xe isotopes Galileo probe HAD solar system C, N, S, O, and & 18O/17O/16O, 12C/13C: He measurement: key isotopes ±1% ±2% Measure the alti- tude profile of Pressure: ±1%, ASI temperature & Temperature: ±1 K pressure Required depth ³10 Measure atmos- bars Profile of atmospheric pheric dynamics dynamics: RSE/DWE including winds & ±5 m/s waves/tides Measure speed of Ortho-para H2 from Understand sound in atmo- Acoustic acoustic anemometer atmospheric sphere to deter- Speed of Sound: ±1% Anemometer, (speed of sound): circulation, the mine hydrogen ASI, MS/TLS molecular mass, processes by ortho/para ratio temperature required which energy is Determine abun- transferred out- CO, PH , AsH , GeH : dances of key dis- 3 3 4 MS/TLS wards from the ±10% interior, and the equilibrium species structure of the Particle optical proper- Characterize ver- cloud layers in ties, size distributions, tical structure, the Ice Giants number and mass composition, and Nephelometer densities, opacity, properties of cloud shapes, and & haze particles. composition Determine net Up & down visible flux: atmospheric ~.4-5 µm up & down Solar uncertain by radiative energy IR flux: 4-50 µm; Net Flux 2%; Protosolar balance; altitude λ/Δλ∼ 0.1-100 Radiometer ~larger --> ±5% profile of thermal ΔFlux ∼0.5Wm−2: requirement IR & solar visible Accuracy ±1% ASI: Atmospheric Structure Instrument; RSE: Radio Science Experiment; AtmAbs: Atmospheric Absorption; DWE: Doppler Wind Experiment; MS: Mass Spectrometer; TLS: Tunable Laser Spectrometer; HAD: Helium Abundance Detector 2 2. Probe Mission Implementation To measure the overall composition, thermal structure, and dynamics of planetary atmospheres requires in situ measurements by a probe carrying a Mass Spectrometer, possibly including a tunable laser spectrometer, an acoustic anemometer to measure the ortho-para H2 ratio from the speed of sound in the atmosphere, a helium abundance detector, and an Atmospheric Structure Instrument to measure the altitude profile of atmospheric temperature vs. pressure. Additional possible instruments include a Nephelometer to characterize cloud structure and aerosol properties, and a Net Flux Radiometer to measure atmospheric radiative energy structure. The probe would target a minimum depth of 10 bars, about 5 scale heights beneath the tropopause with a descent speed largely determined by the instrument capabilities and required sampling periods. Although the probe power, structure, thermal control, and telecommunications will likely allow operations beyond 10 bars, a balance must be found between the total science data volume requirements to achieve the high-priority mission goals, the capability of the probe telecommunications system to transmit the entire science, engineering, and housekeeping data set (including entry accelerometry and pre-entry/entry calibrations) within the descent telecommunications time window, and the probe descent profile allowing the probe to reach 10 bars. An ice giant atmospheric probe with data returned to Earth by an orbiting or flyby Carrier Relay Spacecraft (CRSC) could be carried as an element of a dedicated ice giant planet system exploration mission. For delivery to the proper entry interface point, the CRSC with probe attached is placed on a planetary entry trajectory, and is reoriented for release of the probe. Prior to release, the probe would be configured for coast, entry, and atmospheric descent. Following probe release, a deflect maneuver is performed to place the CRSC on the proper trajectory to receive the probe descent telemetry. The probe is awakened by the coast timer for sequential power-on, warm-up, and health checks prior to arrival at the entry location. The only data collected during entry would be from the entry accelerometers and possibly instrumentation in the heat shield, including sensors to measure heat shield entry ablation. The end of entry is triggered by the accelerometers initiating the parachute deployment sequence, release of the aeroshell, and the initiation of atmospheric descent- science operations. Parachute descent begins near the tropopause by deploying a drogue parachute which pulls off the probe Figure 1. Galileo Jupiter probe entry and descent aft cover which then extracts and profile. (Credit: NASA) deploys the main descent parachute. Once under parachute, the probe heatshield is released and the transmit-only descent telecommunications link from the probe to the CRSC is initiated. Probe science collection and relay transmission strategy would be
Load more

Recommended publications
  • Planetary Science in the Eyes of Giant Telescopes
    Planetary Science in the Eyes of Giant Telescopes Franck Marchis (Carl Sagan Center at the SETI Ins<tute) Feeding the Giants Workshop, Ischia, Italy, August 30 2011, Outline ELTs = Extremely Large Telescopes (E-ELT, TMT, GMT) • Solar System Exploraon – Why Exploring the Solar System with ELTs – Space Mission Programs: Why, Who, Where, When? • Poten<al of the ELTs for Solar System Science – High Angular imaging coupled with spectroscopy in the NIR to explore Io, Titan, and TNOs – Low res UV-NIR spectroscopic combined with All-sky surveys 402 Years of Telescopes Why Planetary Science and the ELTs? • Long heritage of telescopic observaons for the study of the Solar System • Started in 1609 with Galileo Galilei – First publicaon in modern astronomy based on telescope data – Discoveries in the field of Planetary Science • Galilean Moons • Roughness of the Moon surface • Disk appearance of planets & phase of Venus • In 2009, 40% of Keck PR and 25% of Keck AO publicaons are based on Planetary Science results • Strong Public Interest for Planetary Science Toys in Japan Pluto protests 51 Years of Space Missions • First aempts to reach Mars (1960) and Venus (1961) • ~200 solar, lunar and interplanetary missions • More reliable technologies -> more space missions • More accessible technologies -> more countries have access to space (e.g. Japan, China, India,…) • Could the ELTs contribute to Planetary Science in this context? 51 Years of Space Missions (2009) Naonal Geographic 51 Years of Space Missions Inner Solar System NEA 51 Years of Space Missions
    [Show full text]
  • Ice Giants As Exoplanet Analogs K.E
    Ice Giants as Exoplanet Analogs K.E. Mandt, O. Mousis, J. Lunine, B. Marty, T. Smith, A. Luspay- Kuti, A. Aguichine @mommascientist Ice Giants as Exoplanet Analogs • Ice Giant mass/radius common among detected exoplanets • Our Ice Giants only explored by single flybys • Major questions remain about formation process, interior structure and composition, energy balance, and interaction with the Sun • Broad international support for a mission to Uranus and/or Neptune What observations of our Ice Giants would help advance Exoplanet characterization efforts? @mommascientist 5 January 2021 2 Big questions about the Ice Giants • Several studies have designed missions to Uranus and/or Neptune • Common Science Goals - How did the Ice Giants form and evolve? - What is the interior structure of the Ice Giants? - How does the planetary dynamo work? - What is the heat balance of the Ice Giants? - What drives atmospheric dynamics? - How did the rings form and evolve? - How did the moons form and evolve? Any mission to the Ice Giants must address system-level goals. The greatest synergy with current exoplanet research is in the origin, evolution, and current state of the planet. 5 January 2021 3 Giant Planet Formation and Evolution • What was the composition of the solid building blocks? • Did the Protosolar Nebula (PSN) composition vary with distance from the Sun? • What contributed to the noble gas isotope mixtures? Heavy elements trace building block formation, PSN composition, planet formation, and planet evolution @mommascientist Image credit: NASA/STScI
    [Show full text]
  • Arxiv:2012.11628V3 [Astro-Ph.EP] 26 Jan 2021
    manuscript submitted to JGR: Planets The Fundamental Connections Between the Solar System and Exoplanetary Science Stephen R. Kane1, Giada N. Arney2, Paul K. Byrne3, Paul A. Dalba1∗, Steven J. Desch4, Jonti Horner5, Noam R. Izenberg6, Kathleen E. Mandt6, Victoria S. Meadows7, Lynnae C. Quick8 1Department of Earth and Planetary Sciences, University of California, Riverside, CA 92521, USA 2Planetary Systems Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA 3Planetary Research Group, Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA 4School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA 5Centre for Astrophysics, University of Southern Queensland, Toowoomba, QLD 4350, Australia 6Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA 7Department of Astronomy, University of Washington, Seattle, WA 98195, USA 8Planetary Geology, Geophysics and Geochemistry Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA Key Points: • Exoplanetary science is rapidly expanding towards characterization of atmospheres and interiors. • Planetary science has similarly undergone rapid expansion of understanding plan- etary processes and evolution. • Effective studies of exoplanets require models and in-situ data derived from plan- etary science observations and exploration. arXiv:2012.11628v4 [astro-ph.EP] 8 Aug 2021 ∗NSF Astronomy and Astrophysics Postdoctoral Fellow Corresponding author: Stephen R. Kane, [email protected] {1{ manuscript submitted to JGR: Planets Abstract Over the past several decades, thousands of planets have been discovered outside of our Solar System. These planets exhibit enormous diversity, and their large numbers provide a statistical opportunity to place our Solar System within the broader context of planetary structure, atmospheres, architectures, formation, and evolution.
    [Show full text]
  • Neptune Polar Orbiter with Probes*
    NEPTUNE POLAR ORBITER WITH PROBES* 2nd INTERNATIONAL PLANETARY PROBE WORKSHOP, AUGUST 2004, USA Bernard Bienstock(1), David Atkinson(2), Kevin Baines(3), Paul Mahaffy(4), Paul Steffes(5), Sushil Atreya(6), Alan Stern(7), Michael Wright(8), Harvey Willenberg(9), David Smith(10), Robert Frampton(11), Steve Sichi(12), Leora Peltz(13), James Masciarelli(14), Jeffrey Van Cleve(15) (1)Boeing Satellite Systems, MC W-S50-X382, P.O. Box 92919, Los Angeles, CA 90009-2919, [email protected] (2)University of Idaho, PO Box 441023, Moscow, ID 83844-1023, [email protected] (3)JPL, 4800 Oak Grove Blvd., Pasadena, CA 91109-8099, [email protected] (4)NASA Goddard Space Flight Center, Greenbelt, MD 20771, [email protected] (5)Georgia Institute of Technology, 320 Parian Run, Duluth, GA 30097-2417, [email protected] (6)University of Michigan, Space Research Building, 2455 Haward St., Ann Arbor, MI 48109-2143, [email protected] (7)Southwest Research Institute, Department of Space Studies, 1050 Walnut St., Suite 400, Boulder, CO 80302, [email protected] (8)NASA Ames Research Center, Moffett Field, CA 94035-1000, [email protected] (9)4723 Slalom Run SE, Owens Cross Roads, AL 35763, [email protected] (10) Boeing NASA Systems, MC H013-A318, 5301 Bolsa Ave., Huntington Beach, CA 92647-2099, [email protected] (11)Boeing NASA Systems, MC H012-C349, 5301 Bolsa Ave., Huntington Beach, CA 92647-2099 [email protected] (12)Boeing Satellite Systems, MC W-S50-X382, P.O. Box 92919, Los Angeles, CA 90009-2919, [email protected] (13) )Boeing NASA Systems, MC H013-C320, 5301 Bolsa Ave., Huntington Beach, CA 92647-2099, [email protected] (14)Ball Aerospace & Technologies Corp., P.O.
    [Show full text]
  • Abstracts of Extreme Solar Systems 4 (Reykjavik, Iceland)
    Abstracts of Extreme Solar Systems 4 (Reykjavik, Iceland) American Astronomical Society August, 2019 100 — New Discoveries scope (JWST), as well as other large ground-based and space-based telescopes coming online in the next 100.01 — Review of TESS’s First Year Survey and two decades. Future Plans The status of the TESS mission as it completes its first year of survey operations in July 2019 will bere- George Ricker1 viewed. The opportunities enabled by TESS’s unique 1 Kavli Institute, MIT (Cambridge, Massachusetts, United States) lunar-resonant orbit for an extended mission lasting more than a decade will also be presented. Successfully launched in April 2018, NASA’s Tran- siting Exoplanet Survey Satellite (TESS) is well on its way to discovering thousands of exoplanets in orbit 100.02 — The Gemini Planet Imager Exoplanet Sur- around the brightest stars in the sky. During its ini- vey: Giant Planet and Brown Dwarf Demographics tial two-year survey mission, TESS will monitor more from 10-100 AU than 200,000 bright stars in the solar neighborhood at Eric Nielsen1; Robert De Rosa1; Bruce Macintosh1; a two minute cadence for drops in brightness caused Jason Wang2; Jean-Baptiste Ruffio1; Eugene Chiang3; by planetary transits. This first-ever spaceborne all- Mark Marley4; Didier Saumon5; Dmitry Savransky6; sky transit survey is identifying planets ranging in Daniel Fabrycky7; Quinn Konopacky8; Jennifer size from Earth-sized to gas giants, orbiting a wide Patience9; Vanessa Bailey10 variety of host stars, from cool M dwarfs to hot O/B 1 KIPAC, Stanford University (Stanford, California, United States) giants. 2 Jet Propulsion Laboratory, California Institute of Technology TESS stars are typically 30–100 times brighter than (Pasadena, California, United States) those surveyed by the Kepler satellite; thus, TESS 3 Astronomy, California Institute of Technology (Pasadena, Califor- planets are proving far easier to characterize with nia, United States) follow-up observations than those from prior mis- 4 Astronomy, U.C.
    [Show full text]
  • Formation of Telluric Planets and the Origin of Terrestrial Water
    BIO Web of Conferences 2, 01003 (2014) DOI: 10.1051/bioconf/20140201003 C Owned by the authors, published by EDP Sciences, 2014 Formation of telluric planets and the origin of terrestrial water Sean Raymond1;a 1Laboratoire d’Astrophysique de Bordeaux, UMR 5804 Abstract. Simulations of planet formation have failed to reproduce Mars’ small mass (compared with Earth) for 20 years. Here I will present a solution to the Mars problem that invokes large-scale migration of Jupiter and Saturn while they were still embedded in the gaseous protoplanetary disk. Jupiter first migrated inward, then "tacked" and migrated back outward when Saturn caught up to it and became trapped in resonance. If this tack occurred when Jupiter was at 1.5 AU then the inner disk of rocky planetesimals and em- bryos is truncated and the masses and orbits of all four terrestrial planet are quantitatively reproduced. As the giant planets migrate back outward they re-populate the asteroid belt from two different source populations, matching the structure of the current belt. C-type material is also scattered inward to the terrestrial planet-forming zone, delivering about the right amount of water to Earth on 10-50 Myr timescales. 1 Introduction 2 The formation of terrestrial planets As described in the Introduction, the final stages of terrestrial planet formation take place in the presence of any giant planets that may have formed. In addition, it is during this phase that bodies are large enough that during gravitational close encounters they can obtain large eccentricities. Thus, the feeding zones of the terrestrial planets are determined during their final accretion.
    [Show full text]
  • Solar System Interiors, Atmospheres, and Surfaces Investigations Via Radio Links: Goals for the Next Decade
    White Paper for the Planetary Science and Astrobiology Decadal Survey 2023-2032 The National Academies of Sciences, Engineering, and Medicine Solar System Interiors, Atmospheres, and Surfaces Investigations via Radio Links: Goals for the Next Decade SW Asmar1 ([email protected], 818-354-6288), RA Preston1, P Vergados1, DH Atkinson1, T Andert2, H Ando3, CO Ao1, JW Armstrong1, N Ashby4, J-P Barriot5, PM Beauchamp1, DJ Bell1, PL Bender6, M Di Benedetto7, BG Bills1, MK Bird8, TM Bocanegra-Bahamon1, GK Botteon1, S Bruinsma9, DR Buccino1, KL Cahoy10, P Cappuccio7, RK Choudhary11, V Dehant12, C Dumoulin13, D Durante7, CD Edwards1, HM Elliott1, TA Ely1, AI Ermakov14, F Ferri15, FM Flasar16, RG French17, A Genova7, SJ Goossens16,18, B Häusler2, R Helled19, DP Hinson20, MD Hofstadter1, L Iess7, T Imamura21, AP Jongeling1, Ö Karatekin12, Y Kaspi22, MM Kobayashi1, A Komjathy1, AS Konopliv1, ER Kursinski23, TJW Lazio1, S Le Maistre12, FG Lemoine16, RJ Lillis14, IR Linscott24, AJ Mannucci1, EA Marouf25, J-C Marty9, SE Matousek1, K Matsumoto26, EM Mazarico16, V Notaro7, M Parisi1, RS Park1, M Pätzold8, GG Peytaví2, MP Pugh1, NO Rennó27, P Rosenblatt13, D Serra28, RA Simpson20,24, DE Smith10, PG Steffes29, BD Tapley30, S Tellmann8, P Tortora31, SG Turyshev1, T Van Hoolst12, AK Verma32, MM Watkins1, W Williamson1, MA Wieczorek33, P Withers34, M Yseboodt12, N Yu1, M Zannoni31, MT Zuber10 1: Jet Propulsion Laboratory, California Institute of Technology 18. University of Maryland 2: Universität der Bundeswehr München, Germany 19. Universität Zürich, Switzerland 3. Kyoto Sangyo University, Japan 20. SETI Institute 4. National Institute of Standards & Technology 21. The University of Tokyo, Japan 5.
    [Show full text]
  • The Comparative Exploration of the Ice Giant Planets with Twin Spacecraft
    The Comparative Exploration of the Ice Giant Planets with Twin Spacecraft The Comparative Exploration of the Ice Giant Planets with Twin Spacecraft: Unveiling the History of our Solar System Diego Turrini1*, Romolo Politi1, Roberto Peron1, Davide Grassi1, Christina Plainaki1, Mauro Barbieri2, David M. Lucchesi1, Gianfranco Magni1, Francesca Altieri1, Valeria Cottini3, Nicolas Gorius4, Patrick Gaulme5,6, François-Xavier Schmider7, Alberto Adriani1, Giuseppe Piccioni1 1 Institute for Space Astrophysics and Planetology INAF-IAPS, Italy. 2 Center of Studies and Activities for Space CISAS, University of Padova, Italy. 3 University of Maryland, USA. 4 Catholic University of America, USA 5 Department of Astronomy, New Mexico State University, P.O. Box 30001, MSC 4500, Las Cruces, NM 88003-8001, USA 6 Apache Point Observatory, 2001 Apache Point Road, P.O. Box 59, Sunspot, NM 88349, USA 7 Laboratoire Lagrange, Observatoire de la Côte d'Azur, France Abstract In the course of the selection of the scientific themes for the second and third L-class missions of the Cosmic Vision 2015-2025 program of the European Space Agency, the exploration of the ice giant planets Uranus and Neptune was defined “a timely milestone, fully appropriate for an L class mission”. Among the proposed scientific themes, we presented the scientific case of exploring both planets and their satellites in the framework of a single L-class mission and proposed a mission scenario that could allow to achieve this result. In this work we present an updated and more complete discussion of the scientific rationale and of the mission concept for a comparative exploration of the ice giant planets Uranus and Neptune and of their satellite systems with twin spacecraft.
    [Show full text]
  • Exploration of the Ice Giant Systems
    Exploration of the Ice Giant Systems A White Paper for NASA's Planetary Science and Astrobiology Decadal Survey 2023-2032 Uranus (left) [1] and Neptune (right) (NASA) Lead Authors: Chloe B. Beddingfield1,2 1The SETI Institute 2NASA Ames Research Center [email protected] (972) 415-7604 Cheng Li3 3University of California, Berkeley [email protected] Primary Co-Authors: Sushil Atreya4 Patricia Beauchamp5 Ian Cohen6 Jonathan Fortney7 Heidi Hammel8 Matthew Hedman9 Mark Hofstadter5 Abigail Rymer6 Paul Schenk10 Mark Showalter1 4University of Michigan, Ann Arbor, 5Jet Propulsion Laboratory, 6Johns Hopkins University Applied Physics Laboratory, 7University of California, Santa Cruz, 8Association of Universities for Research in Astronomy, 9University of Idaho, 10Lunar and Planetary Institute Additional Coauthors and Endorsers: For a full list of the 145 authors and endorsers, see the following link: https://docs.google.com/document/d/158h8ZK0HXp- DSQqVhV7gcGzjHqhUJ_2MzQAsRg3sxXw/edit?usp=sharing Motivation Ice giants are the only unexplored class of planet in our Solar System. Much that we currently know about these systems challenges our understanding of how planets, rings, satellites, and magnetospheres form and evolve. We assert that an ice giant Flagship mission with an atmospheric probe should be a priority for the decade 2023-2032. Investigation of Uranus or Neptune would advance fundamental understanding of many key issues in Solar System formation: 1) how ice giants formed and migrated through the Solar System; 2) what processes control the current conditions of this class of planet, its rings, satellites, and magnetospheres; 3) how the rings and satellites formed and evolved, and how Triton was captured from the Kuiper Belt; 4) whether the large satellites of the ice giants are ocean worlds that may harbor life now or in the past; and 5) the range of possible characteristics for exoplanets.
    [Show full text]
  • 9:00 Pm SFAA ANNUAL AWARDS and MEMBERSHIP DINNER MARIPOSA HUNTER’S POINT YACHT CLUB 405 Terry A
    Vol. 64, No. 1 – January2016 FRIDAY, JANUARY 22, 2015 - 5:00 pm – 9:00 pm SFAA ANNUAL AWARDS AND MEMBERSHIP DINNER MARIPOSA HUNTER’S POINT YACHT CLUB 405 Terry A. Francois Boulevard San Francisco Directions: http://www.yelp.com/map/mariposa-hunters-point-yacht-club-san-francisco Dear Members, our Annual January get-together will be Friday, January 22nd, 2016 from 5:00 to 9:00 at the Mariposa, Hunter's Point Yacht Club. There are many things to celebrate in this fun atmosphere, with tacos served by El Tonayense, salads & more, along with a full cash bar. All members are invited and SFAA will be paying for food. Non-members are welcome at a cost of $25. Telescopes will be set up on the patio, which provides beautiful views of the bay. We will be celebrating a year when we have made a successful transition to the Presidio, have continued the success of the sharing and viewing we have on Mt Tam, expanded and strengthened our City Star Parties and volunteered at many schools. Our Yosemite trip was very successful and the opportunity to tour Lick Observatory will not be soon forgotten. We will also be welcoming new members to our board and commending those whose work and commitment, our club could not function without. We look forward to enjoying the evening with all those who enjoy the night sky with the San Francisco Amateur Astronomers. There is plenty of parking, as well as easy access from the KT line and the 22 bus. Please RSVP at [email protected] Anil Chopra 2016 SAN FRANCISCO AMATEUR ASTRONOMERS GENERAL ELECTION The following members have been elected to serve as San Francisco Amateur Astronomers’ Officers and Directors for calendar year 2016.
    [Show full text]
  • Astro2020 Science White Paper Solar System Ice Giants
    Solar System Exoplanets White Paper Astro2020 Science White Paper Solar System Ice Giants: Exoplanets in our Backyard. Thematic Areas: ☒ Planetary Systems ☐ Star and Planet Formation ☐Formation and Evolution of Compact Objects ☐ Cosmology and Fundamental Physics ☐Stars and Stellar Evolution ☐Resolved Stellar Populations and their Environments ☐Galaxy Evolution ☐Multi‐Messenger Astronomy and Astrophysics Principal Author: Name: Abigail Rymer Institution: Johns Hopkins Applied Physics Laboratory Email: [email protected] Phone: 443‐778‐2736 Co‐authors: Kathleen Mandt1, Dana Hurley1, Carey Lisse1, Noam Izenberg1, H.Todd Smith1, Joseph Westlake1, Emma Bunce2, Christopher Arridge3, Adam Masters4, Mark Hofstadter5, Amy Simon6, Pontus Brandt1, George Clark1, Ian Cohen1, Robert Allen1, Sarah Vine1, Kenneth Hansen7, George Hospodarsky8, William Kurth8, Paul Romani6, Laurent Lamy9, Philippe Zarka9, Hao Cao10, Carol Paty11, Matthew Hedman12, Elias Roussos13, Dale Cruikshank14, William Farrell6, Paul Fieseler5, Andrew Coates15, Roger Yelle16, Christopher Parkinson7, Burkhard Militzer17, Denis Grodent18, Peter Kollmann1, Ralph McNutt1, Nicolas André19, Nathan Strange5, Jason Barnes20, Luke Dones21, Tilmann Denk22, Julie Rathbun23, Jonathan Lunine12, Ravi Desai4, Corey Cochrane5, Kunio M. Sayanagi24, Frank Postberg25, Robert Ebert21, Thomas Hill26, Ingo Mueller- Wodarg4, Leonardo Regoli7, Duane Pontius27, Sabine Stanley1,49, Thomas Greathouse21, Joachim Saur28, Essam Marouf29, Jan Bergman30, Chuck Higgins31, Robert Johnson32, Michelle Thomsen23,
    [Show full text]
  • Ice Giants Decadal Study
    SDO-12345 Ice Giants Decadal Study Revision 6/3/2010 William B. Hubbard [email protected] SDO-12345 Planetary Science Decadal Survey Mission Concept Study Final Report Executive Summary.............................................................................................................. 4 1. Scientific Objectives .................................................................................................... 5 Science Questions and Objectives ................................................................................................................................... 5 Science Traceability ............................................................................................................................................................ 12 2. High-Level Mission Concept .......................................................................................14 Study Request & Concept Maturity Level .................................................................................................................. 14 Overview ................................................................................................................................................................................. 14 Technology Maturity .......................................................................................................................................................... 17 Key Trades .............................................................................................................................................................................
    [Show full text]