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Arxiv:1912.09192V2 [Astro-Ph.EP] 24 Feb 2020
Draft version February 25, 2020 Typeset using LATEX preprint style in AASTeX62 Photometric analyses of Saturn's small moons: Aegaeon, Methone and Pallene are dark; Helene and Calypso are bright. M. M. Hedman,1 P. Helfenstein,2 R. O. Chancia,1, 3 P. Thomas,2 E. Roussos,4 C. Paranicas,5 and A. J. Verbiscer6 1Department of Physics, University of Idaho, Moscow, ID 83844 2Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca NY 14853 3Center for Imaging Science, Rochester Institute of Technology, Rochester NY 14623 4Max Planck Institute for Solar System Research, G¨ottingen,Germany 37077 5APL, John Hopkins University, Laurel MD 20723 6Department of Astronomy, University of Virginia, Charlottesville, VA 22904 ABSTRACT We examine the surface brightnesses of Saturn's smaller satellites using a photometric model that explicitly accounts for their elongated shapes and thus facilitates compar- isons among different moons. Analyses of Cassini imaging data with this model reveals that the moons Aegaeon, Methone and Pallene are darker than one would expect given trends previously observed among the nearby mid-sized satellites. On the other hand, the trojan moons Calypso and Helene have substantially brighter surfaces than their co-orbital companions Tethys and Dione. These observations are inconsistent with the moons' surface brightnesses being entirely controlled by the local flux of E-ring par- ticles, and therefore strongly imply that other phenomena are affecting their surface properties. The darkness of Aegaeon, Methone and Pallene is correlated with the fluxes of high-energy protons, implying that high-energy radiation is responsible for darkening these small moons. Meanwhile, Prometheus and Pandora appear to be brightened by their interactions with nearby dusty F ring, implying that enhanced dust fluxes are most likely responsible for Calypso's and Helene's excess brightness. -
A Deeper Look at the Colors of the Saturnian Irregular Satellites Arxiv
A deeper look at the colors of the Saturnian irregular satellites Tommy Grav Harvard-Smithsonian Center for Astrophysics, MS51, 60 Garden St., Cambridge, MA02138 and Instiute for Astronomy, University of Hawaii, 2680 Woodlawn Dr., Honolulu, HI86822 [email protected] James Bauer Jet Propulsion Laboratory, California Institute of Technology 4800 Oak Grove Dr., MS183-501, Pasadena, CA91109 [email protected] September 13, 2018 arXiv:astro-ph/0611590v2 8 Mar 2007 Manuscript: 36 pages, with 11 figures and 5 tables. 1 Proposed running head: Colors of Saturnian irregular satellites Corresponding author: Tommy Grav MS51, 60 Garden St. Cambridge, MA02138 USA Phone: (617) 384-7689 Fax: (617) 495-7093 Email: [email protected] 2 Abstract We have performed broadband color photometry of the twelve brightest irregular satellites of Saturn with the goal of understanding their surface composition, as well as their physical relationship. We find that the satellites have a wide variety of different surface colors, from the negative spectral slopes of the two retrograde satellites S IX Phoebe (S0 = −2:5 ± 0:4) and S XXV Mundilfari (S0 = −5:0 ± 1:9) to the fairly red slope of S XXII Ijiraq (S0 = 19:5 ± 0:9). We further find that there exist a correlation between dynamical families and spectral slope, with the prograde clusters, the Gallic and Inuit, showing tight clustering in colors among most of their members. The retrograde objects are dynamically and physically more dispersed, but some internal structure is apparent. Keywords: Irregular satellites; Photometry, Satellites, Surfaces; Saturn, Satellites. 3 1 Introduction The satellites of Saturn can be divided into two distinct groups, the regular and irregular, based on their orbital characteristics. -
Models of a Protoplanetary Disk Forming In-Situ the Galilean And
Models of a protoplanetary disk forming in-situ the Galilean and smaller nearby satellites before Jupiter is formed Dimitris M. Christodoulou1, 2 and Demosthenes Kazanas3 1 Lowell Center for Space Science and Technology, University of Massachusetts Lowell, Lowell, MA, 01854, USA. 2 Dept. of Mathematical Sciences, Univ. of Massachusetts Lowell, Lowell, MA, 01854, USA. E-mail: [email protected] 3 NASA/GSFC, Laboratory for High-Energy Astrophysics, Code 663, Greenbelt, MD 20771, USA. E-mail: [email protected] March 5, 2019 ABSTRACT We fit an isothermal oscillatory density model of Jupiter’s protoplanetary disk to the present-day Galilean and other nearby satellites and we determine the radial scale length of the disk, the equation of state and the central density of the primordial gas, and the rotational state of the Jovian nebula. Although the radial density profile of Jupiter’s disk was similar to that of the solar nebula, its rotational support against self-gravity was very low, a property that also guaranteed its long-term stability against self-gravity induced instabilities for millions of years. Keywords. planets and satellites: dynamical evolution and stability—planets and satellites: formation—protoplanetary disks 1. Introduction 2. Intrinsic and Oscillatory Solutions of the Isothermal Lane-Emden Equation with Rotation In previous work (Christodoulou & Kazanas 2019a,b), we pre- sented and discussed an isothermal model of the solar nebula 2.1. Intrinsic Analytical Solutions capable of forming protoplanets long before the Sun was actu- The isothermal Lane-Emden equation (Lane 1869; Emden 1907) ally formed, very much as currently observed in high-resolution with rotation (Christodoulou & Kazanas 2019a) takes the form (∼1-5 AU) observations of protostellar disks by the ALMA tele- of a second-order nonlinear inhomogeneous equation, viz. -
JUICE Red Book
ESA/SRE(2014)1 September 2014 JUICE JUpiter ICy moons Explorer Exploring the emergence of habitable worlds around gas giants Definition Study Report European Space Agency 1 This page left intentionally blank 2 Mission Description Jupiter Icy Moons Explorer Key science goals The emergence of habitable worlds around gas giants Characterise Ganymede, Europa and Callisto as planetary objects and potential habitats Explore the Jupiter system as an archetype for gas giants Payload Ten instruments Laser Altimeter Radio Science Experiment Ice Penetrating Radar Visible-Infrared Hyperspectral Imaging Spectrometer Ultraviolet Imaging Spectrograph Imaging System Magnetometer Particle Package Submillimetre Wave Instrument Radio and Plasma Wave Instrument Overall mission profile 06/2022 - Launch by Ariane-5 ECA + EVEE Cruise 01/2030 - Jupiter orbit insertion Jupiter tour Transfer to Callisto (11 months) Europa phase: 2 Europa and 3 Callisto flybys (1 month) Jupiter High Latitude Phase: 9 Callisto flybys (9 months) Transfer to Ganymede (11 months) 09/2032 – Ganymede orbit insertion Ganymede tour Elliptical and high altitude circular phases (5 months) Low altitude (500 km) circular orbit (4 months) 06/2033 – End of nominal mission Spacecraft 3-axis stabilised Power: solar panels: ~900 W HGA: ~3 m, body fixed X and Ka bands Downlink ≥ 1.4 Gbit/day High Δv capability (2700 m/s) Radiation tolerance: 50 krad at equipment level Dry mass: ~1800 kg Ground TM stations ESTRAC network Key mission drivers Radiation tolerance and technology Power budget and solar arrays challenges Mass budget Responsibilities ESA: manufacturing, launch, operations of the spacecraft and data archiving PI Teams: science payload provision, operations, and data analysis 3 Foreword The JUICE (JUpiter ICy moon Explorer) mission, selected by ESA in May 2012 to be the first large mission within the Cosmic Vision Program 2015–2025, will provide the most comprehensive exploration to date of the Jovian system in all its complexity, with particular emphasis on Ganymede as a planetary body and potential habitat. -
The Moons of Jupiter – Orbital Synchrony 3
The Moons of Jupiter – Orbital Synchrony 3 The figure above shows the orbits of many of Jupiter's numerous satellites. Each of these ‘moons’ orbits Jupiter in a different number of days. The image to the right shows the appearance of one of Jupiter’s moons Callisto. The orbit periods of many of the moons have simple relationships between them. When Jupiter’s moon Ganymede orbits 1/2 way around Jupiter, Jupiter's moon Europa orbits Jupiter once. When Jupiter’s moon Leda orbits Jupiter once, Ganymede orbits Jupiter 34 times. When Jupiter's moon Leda orbits Jupiter five times, the more distant moon Thelxinoe orbits Jupiter twice. When Leda orbits Jupiter three times, the moon Kalyke orbits Jupiter once. Example: 1/2 x Ganymede = 1 x Europa, so in the time it takes Europa to go once around Jupiter, Ganymede goes only ½ way around in its orbit. Problem 1 - How many times does Ganymede orbit Jupiter in the time it takes Europa to orbit six times? Problem 2 – How many times does Leda orbit Jupiter in the time it takes Ganymede to orbit Jupiter 6 times? Problem 3 - How many orbits will Thelxinoe have to complete around Jupiter before Kalyke orbits exactly five times? Space Math http://spacemath.gsfc.nasa.gov Answer Key 3 Problem 1 - How many times does Ganymede orbit Jupiter in the time it takes Europa to orbit six times? Answer: The information says that Europa orbits once when Ganymede orbits 1/2 times, so 1 x Europa = 1/2 x Ganymede and so 2 x Europa = 1 x Ganymede. -
The Orbits of Saturn's Small Satellites Derived From
The Astronomical Journal, 132:692–710, 2006 August A # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE ORBITS OF SATURN’S SMALL SATELLITES DERIVED FROM COMBINED HISTORIC AND CASSINI IMAGING OBSERVATIONS J. N. Spitale CICLOPS, Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301; [email protected] R. A. Jacobson Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 C. C. Porco CICLOPS, Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 and W. M. Owen, Jr. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 Received 2006 February 28; accepted 2006 April 12 ABSTRACT We report on the orbits of the small, inner Saturnian satellites, either recovered or newly discovered in recent Cassini imaging observations. The orbits presented here reflect improvements over our previously published values in that the time base of Cassini observations has been extended, and numerical orbital integrations have been performed in those cases in which simple precessing elliptical, inclined orbit solutions were found to be inadequate. Using combined Cassini and Voyager observations, we obtain an eccentricity for Pan 7 times smaller than previously reported because of the predominance of higher quality Cassini data in the fit. The orbit of the small satellite (S/2005 S1 [Daphnis]) discovered by Cassini in the Keeler gap in the outer A ring appears to be circular and coplanar; no external perturbations are appar- ent. Refined orbits of Atlas, Prometheus, Pandora, Janus, and Epimetheus are based on Cassini , Voyager, Hubble Space Telescope, and Earth-based data and a numerical integration perturbed by all the massive satellites and each other. -
Astrometric Positions for 18 Irregular Satellites of Giant Planets from 23
Astronomy & Astrophysics manuscript no. Irregulares c ESO 2018 October 20, 2018 Astrometric positions for 18 irregular satellites of giant planets from 23 years of observations,⋆,⋆⋆,⋆⋆⋆,⋆⋆⋆⋆ A. R. Gomes-Júnior1, M. Assafin1,†, R. Vieira-Martins1, 2, 3,‡, J.-E. Arlot4, J. I. B. Camargo2, 3, F. Braga-Ribas2, 5,D.N. da Silva Neto6, A. H. Andrei1, 2,§, A. Dias-Oliveira2, B. E. Morgado1, G. Benedetti-Rossi2, Y. Duchemin4, 7, J. Desmars4, V. Lainey4, W. Thuillot4 1 Observatório do Valongo/UFRJ, Ladeira Pedro Antônio 43, CEP 20.080-090 Rio de Janeiro - RJ, Brazil e-mail: [email protected] 2 Observatório Nacional/MCT, R. General José Cristino 77, CEP 20921-400 Rio de Janeiro - RJ, Brazil e-mail: [email protected] 3 Laboratório Interinstitucional de e-Astronomia - LIneA, Rua Gal. José Cristino 77, Rio de Janeiro, RJ 20921-400, Brazil 4 Institut de mécanique céleste et de calcul des éphémérides - Observatoire de Paris, UMR 8028 du CNRS, 77 Av. Denfert-Rochereau, 75014 Paris, France e-mail: [email protected] 5 Federal University of Technology - Paraná (UTFPR / DAFIS), Rua Sete de Setembro, 3165, CEP 80230-901, Curitiba, PR, Brazil 6 Centro Universitário Estadual da Zona Oeste, Av. Manual Caldeira de Alvarenga 1203, CEP 23.070-200 Rio de Janeiro RJ, Brazil 7 ESIGELEC-IRSEEM, Technopôle du Madrillet, Avenue Galilée, 76801 Saint-Etienne du Rouvray, France Received: Abr 08, 2015; accepted: May 06, 2015 ABSTRACT Context. The irregular satellites of the giant planets are believed to have been captured during the evolution of the solar system. Knowing their physical parameters, such as size, density, and albedo is important for constraining where they came from and how they were captured. -
Exep Science Plan Appendix (SPA) (This Document)
ExEP Science Plan, Rev A JPL D: 1735632 Release Date: February 15, 2019 Page 1 of 61 Created By: David A. Breda Date Program TDEM System Engineer Exoplanet Exploration Program NASA/Jet Propulsion Laboratory California Institute of Technology Dr. Nick Siegler Date Program Chief Technologist Exoplanet Exploration Program NASA/Jet Propulsion Laboratory California Institute of Technology Concurred By: Dr. Gary Blackwood Date Program Manager Exoplanet Exploration Program NASA/Jet Propulsion Laboratory California Institute of Technology EXOPDr.LANET Douglas Hudgins E XPLORATION PROGRAMDate Program Scientist Exoplanet Exploration Program ScienceScience Plan Mission DirectorateAppendix NASA Headquarters Karl Stapelfeldt, Program Chief Scientist Eric Mamajek, Deputy Program Chief Scientist Exoplanet Exploration Program JPL CL#19-0790 JPL Document No: 1735632 ExEP Science Plan, Rev A JPL D: 1735632 Release Date: February 15, 2019 Page 2 of 61 Approved by: Dr. Gary Blackwood Date Program Manager, Exoplanet Exploration Program Office NASA/Jet Propulsion Laboratory Dr. Douglas Hudgins Date Program Scientist Exoplanet Exploration Program Science Mission Directorate NASA Headquarters Created by: Dr. Karl Stapelfeldt Chief Program Scientist Exoplanet Exploration Program Office NASA/Jet Propulsion Laboratory California Institute of Technology Dr. Eric Mamajek Deputy Program Chief Scientist Exoplanet Exploration Program Office NASA/Jet Propulsion Laboratory California Institute of Technology This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. © 2018 California Institute of Technology. Government sponsorship acknowledged. Exoplanet Exploration Program JPL CL#19-0790 ExEP Science Plan, Rev A JPL D: 1735632 Release Date: February 15, 2019 Page 3 of 61 Table of Contents 1. -
Cassini Observations of Saturn's Irregular Moons
EPSC Abstracts Vol. 12, EPSC2018-103-1, 2018 European Planetary Science Congress 2018 EEuropeaPn PlanetarSy Science CCongress c Author(s) 2018 Cassini Observations of Saturn's Irregular Moons Tilmann Denk (1) and Stefano Mottola (2) (1) Freie Universität Berlin, Germany ([email protected]), (2) DLR Berlin, Germany 1. Introduction two prograde irregulars are slower than ~13 h, while the periods of all but two retrogrades are faster than With the ISS-NAC camera of the Cassini spacecraft, ~13 h. The fastest period (Hati) is much slower than we obtained photometric lightcurves of 25 irregular the disruption rotation barrier for asteroids (~2.3 h), moons of Saturn. The goal was to derive basic phys- indicating that Saturn's irregulars may be rubble piles ical properties of these objects (like rotational periods, of rather low densities, possibly as low as of comets. shapes, pole-axis orientations, possible global color variations, ...) and to get hints on their formation and Table: Rotational periods of 25 Saturnian irregulars evolution. Our campaign marks the first utilization of an interplanetary probe for a systematic photometric Moon Approx. size Rotational period survey of irregular moons. name [km] [h] Hati 5 5.45 ± 0.04 The irregular moons are a class of objects that is very Mundilfari 7 6.74 ± 0.08 distinct from the inner moons of Saturn. Not only are Loge 5 6.9 ± 0.1 ? they more numerous (38 versus 24), but also occupy Skoll 5 7.26 ± 0.09 (?) a much larger volume within the Hill sphere of Suttungr 7 7.67 ± 0.02 Saturn. -
Hesiod Theogony.Pdf
Hesiod (8th or 7th c. BC, composed in Greek) The Homeric epics, the Iliad and the Odyssey, are probably slightly earlier than Hesiod’s two surviving poems, the Works and Days and the Theogony. Yet in many ways Hesiod is the more important author for the study of Greek mythology. While Homer treats cer- tain aspects of the saga of the Trojan War, he makes no attempt at treating myth more generally. He often includes short digressions and tantalizes us with hints of a broader tra- dition, but much of this remains obscure. Hesiod, by contrast, sought in his Theogony to give a connected account of the creation of the universe. For the study of myth he is im- portant precisely because his is the oldest surviving attempt to treat systematically the mythical tradition from the first gods down to the great heroes. Also unlike the legendary Homer, Hesiod is for us an historical figure and a real per- sonality. His Works and Days contains a great deal of autobiographical information, in- cluding his birthplace (Ascra in Boiotia), where his father had come from (Cyme in Asia Minor), and the name of his brother (Perses), with whom he had a dispute that was the inspiration for composing the Works and Days. His exact date cannot be determined with precision, but there is general agreement that he lived in the 8th century or perhaps the early 7th century BC. His life, therefore, was approximately contemporaneous with the beginning of alphabetic writing in the Greek world. Although we do not know whether Hesiod himself employed this new invention in composing his poems, we can be certain that it was soon used to record and pass them on. -
CLARK PLANETARIUM SOLAR SYSTEM FACT SHEET Data Provided by NASA/JPL and Other Official Sources
CLARK PLANETARIUM SOLAR SYSTEM FACT SHEET Data provided by NASA/JPL and other official sources. This handout ©July 2013 by Clark Planetarium (www.clarkplanetarium.org). May be freely copied by professional educators for classroom use only. The known satellites of the Solar System shown here next to their planets with their sizes (mean diameter in km) in parenthesis. The planets and satellites (with diameters above 1,000 km) are depicted in relative size (with Earth = 0.500 inches) and are arranged in order by their distance from the planet, with the closest at the top. Distances from moon to planet are not listed. Mercury Jupiter Saturn Uranus Neptune Pluto • 1- Metis (44) • 26- Hermippe (4) • 54- Hegemone (3) • 1- S/2009 S1 (1) • 33- Erriapo (10) • 1- Cordelia (40.2) (Dwarf Planet) (no natural satellites) • 2- Adrastea (16) • 27- Praxidike (6.8) • 55- Aoede (4) • 2- Pan (26) • 34- Siarnaq (40) • 2- Ophelia (42.8) • Charon (1186) • 3- Bianca (51.4) Venus • 3- Amalthea (168) • 28- Thelxinoe (2) • 56- Kallichore (2) • 3- Daphnis (7) • 35- Skoll (6) • Nix (60?) • 4- Thebe (98) • 29- Helike (4) • 57- S/2003 J 23 (2) • 4- Atlas (32) • 36- Tarvos (15) • 4- Cressida (79.6) • Hydra (50?) • 5- Desdemona (64) • 30- Iocaste (5.2) • 58- S/2003 J 5 (4) • 5- Prometheus (100.2) • 37- Tarqeq (7) • Kerberos (13-34?) • 5- Io (3,643.2) • 6- Pandora (83.8) • 38- Greip (6) • 6- Juliet (93.6) • 1- Naiad (58) • 31- Ananke (28) • 59- Callirrhoe (7) • Styx (??) • 7- Epimetheus (119) • 39- Hyrrokkin (8) • 7- Portia (135.2) • 2- Thalassa (80) • 6- Europa (3,121.6) -
Cladistical Analysis of the Jovian Satellites. T. R. Holt1, A. J. Brown2 and D
47th Lunar and Planetary Science Conference (2016) 2676.pdf Cladistical Analysis of the Jovian Satellites. T. R. Holt1, A. J. Brown2 and D. Nesvorny3, 1Center for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne, Victoria, Australia [email protected], 2SETI Institute, Mountain View, California, USA, 3Southwest Research Institute, Department of Space Studies, Boulder, CO. USA. Introduction: Surrounding Jupiter there are multi- Results: ple satellites, 67 known to-date. The most recent classi- fication system [1,2], based on orbital characteristics, uses the largest member of the group as the name and example. The closest group to Jupiter is the prograde Amalthea group, 4 small satellites embedded in a ring system. Moving outwards there are the famous Galilean moons, Io, Europa, Ganymede and Callisto, whose mass is similar to terrestrial planets. The final and largest group, is that of the outer Irregular satel- lites. Those irregulars that show a prograde orbit are closest to Jupiter and have previously been classified into three families [2], the Themisto, Carpo and Hi- malia groups. The remainder of the irregular satellites show a retrograde orbit, counter to Jupiter's rotation. Based on similarities in semi-major axis (a), inclination (i) and eccentricity (e) these satellites have been grouped into families [1,2]. In order outward from Jupiter they are: Ananke family (a 2.13x107 km ; i 148.9o; e 0.24); Carme family (a 2.34x107 km ; i 164.9o; e 0.25) and the Pasiphae family (a 2:36x107 km ; i 151.4o; e 0.41). There are some irregular satellites, recently discovered in 2003 [3], 2010 [4] and 2011[5], that have yet to be named or officially classified.