DOCSLIB.ORG

Iapetus and Enceladus: First Contributions of High-Precision Geophysical Modeling to Solar System Chronometry and Chronology

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Iapetus and Enceladus: First Contributions of High-Precision Geophysical Modeling to Solar System Chronometry and Chronology Planetary Chronology Workshop 2006 6023.pdf IAPETUS AND ENCELADUS: FIRST CONTRIBUTIONS OF HIGH-PRECISION GEOPHYSICAL MODELING TO SOLAR SYSTEM CHRONOMETRY AND CHRONOLOGY. D. L. Matson1, J. C. Castillo1, T. V. Johnson1, and J. Lunine2,3, 1Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, 91109 Pasadena, CA, USA ([email protected]), 2Lunar & Planetary Lab, University of Ari- zona, 1629 E. University Blvd, 85721, Tucson, AZ, USA / INAF, Istituto di Fisica dello Spazio Interplanetario Via del Fosso del Cavaliere 100, 00133, Rome ITALY. Introduction: As a result of the Cassini Imaging Absolute dates indicate that the Earth-Moon system and Radio Science data, the Saturnian satellite densi- formed after Iapetus and the Saturnian system. The ties are now available to high accuracy (Jacobson et al. fact that Iapetus formed before the Moon may give us 2005). The weighted average density for the medium- a different prospective on dating surface by impacts. sized, regular Saturnian satellites is ~1230 kg/m3, (4) An important aspect of this new chronol- about 30% lower than the average (uncompressed) ogy concept is the use of CAIs time of formation as a density for the Galilean satellites. This new data, com- reference for the formation of the Solar System. While bined with updated values for parameters involved in CAIs’ absolute age has been determined with an un- thermal modeling, result in interiors much colder than certainty of (+/-0.000 6 By), solids older than CAIs previously considered in the series of geophysical have been identified [9]. Determining the chronology models produced after the visit of the Voyager mission of the formation the first solids is crucial to future ap- to the Saturnian system. In order to drive endogenic plication of Iapetus’ age to the Solar system. (tectonic) activity and dynamical evolution, Castillo et al. [1] and Matson et al. [2] have proposed short-lived Conclusion: Previous studies using 26Al as a fine- radiogenic species as a potential heat source. scale radiochronometer treated meteorites only. Future Fine-Scale Radiochronometry: This opens the models must unify the different components of the door to fine-scale radiochronometry in planetary sci- Solar system chronology on a framework of absolute ences, because the main short-lived contributors are dates. We will be able to see hitherto for hidden rela- 26Al (half-life = 0.716 My) and 60Fe (half-life = 1.5 tionships between nucleosynthesis, first solids and My). Modeling of Iapetus’ spin rate evolution [1], planetesimal formation, CAIs and chondrules, to the Enceladus’ thermal state [2], but also constraints on formation of the different giant planet systems (in Mimas and Tethys orbital evolution and Rhea’s inter- agreement in dynamical studies), and the formation of nal structure, either agree or are consistent with a for- the inner Solar System. Implications also regard the mation time within 3 My after the creation of the Cal- formation and evolution of extrasolar systems. cium-Aluminum Inclusions (CAIs). The latter are our reference time scale as their occurrences in chondrites Acknowledgements: We thank S. Krot and G. have been dated precisely as 4.5672 +/- 0.0006 By [3]. Huss for very helpful discussions. Implications: Such a result opens new frontiers in This work was carried out by the Jet Propulsion planetary sciences, some of them will be discussed Laboratory, California Institute of Technology, under during the presentation: NASA contract. (1) Finding the evidence for 26Al in the early Saturnian system provides strong constraint on the References: [1] Castillo J. et al. (2005) BAAS 37, wide distribution of this radionuclide in the early Solar 39.04. [2] Matson D. L. et al. (2006) LPS XXXVII, System. This has direct implications on the origin of 2219. [3] Amelin Y. et al. (2002) Science 297, 1678- 26 Al, as well as the formation of other short-lived ra- 1681. [4] Young E. D. et al. (2005) Science 308, 223- 60 dionuclides, especially Fe. 227. [5] Mostefaoui S. et al. (2005) ApJ 625, 271-277. (2) Inferring times of formation from the heat [6] Shukolyukov A. and Lugmair G. (1993) Science required in thermal models is dependent on the initial 259, 1138-1142. [7] Giese et al. BAAS 37 (2005). [8] abundance of the major short-lived radionuclides. For Castillo et al. manuscript in preparation. [9] Shu- a long time, a canonical abundance has been recog- 26 kolyukov A. and Lugmair G. (2004) GCA 68, 2875- nized for Al. However, recently a supercanonical 2888. value has been proposed [4]. Also, there is no agreed canonical value for 60Fe, whose initial abundance has been updated toward higher values [5] since its identi- fication in meteorites [6]. (3) It is now possible to link relative and ab- solute dates. Both data are available for Iapetus [7, 8]. .
Load more

Recommended publications
  • 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.
    [Show full text]
  • Accretion of Saturn's Mid-Sized Moons During the Viscous
    Accretion of Saturn’s mid-sized moons during the viscous spreading of young massive rings: solving the paradox of silicate-poor rings versus silicate-rich moons. Sébastien CHARNOZ *,1 Aurélien CRIDA 2 Julie C. CASTILLO-ROGEZ 3 Valery LAINEY 4 Luke DONES 5 Özgür KARATEKIN 6 Gabriel TOBIE 7 Stephane MATHIS 1 Christophe LE PONCIN-LAFITTE 8 Julien SALMON 5,1 (1) Laboratoire AIM, UMR 7158, Université Paris Diderot /CEA IRFU /CNRS, Centre de l’Orme les Merisiers, 91191, Gif sur Yvette Cedex France (2) Université de Nice Sophia-antipolis / C.N.R.S. / Observatoire de la Côte d'Azur Laboratoire Cassiopée UMR6202, BP4229, 06304 NICE cedex 4, France (3) Jet Propulsion Laboratory, California Institute of Technology, M/S 79-24, 4800 Oak Drive Pasadena, CA 91109 USA (4) IMCCE, Observatoire de Paris, UMR 8028 CNRS / UPMC, 77 Av. Denfert-Rochereau, 75014, Paris, France (5) Department of Space Studies, Southwest Research Institute, Boulder, Colorado 80302, USA (6) Royal Observatory of Belgium, Avenue Circulaire 3, 1180 Uccle, Bruxelles, Belgium (7) Université de Nantes, UFR des Sciences et des Techniques, Laboratoire de Planétologie et Géodynamique, 2 rue de la Houssinière, B.P. 92208, 44322 Nantes Cedex 3, France (8) SyRTE, Observatoire de Paris, UMR 8630 du CNRS, 77 Av. Denfert-Rochereau, 75014, Paris, France (*) To whom correspondence should be addressed ([email protected]) 1 ABSTRACT The origin of Saturn’s inner mid-sized moons (Mimas, Enceladus, Tethys, Dione and Rhea) and Saturn’s rings is debated. Charnoz et al. (2010) introduced the idea that the smallest inner moons could form from the spreading of the rings’ edge while Salmon et al.
    [Show full text]
  • Rings and Moons of Saturn 1 Rings and Moons of Saturn
    PYTS/ASTR 206 – Rings and Moons of Saturn 1 Rings and Moons of Saturn PTYS/ASTR 206 – The Golden Age of Planetary Exploration Shane Byrne – [email protected] PYTS/ASTR 206 – Rings and Moons of Saturn 2 In this lecture… Rings Discovery What they are How to form rings The Roche limit Dynamics Voyager II – 1981 Gaps and resonances Shepherd moons Voyager I – 1980 – Titan Inner moons Tectonics and craters Cassini – ongoing Enceladus – a very special case Outer Moons Captured Phoebe Iapetus and Hyperion Spray-painted with Phoebe debris PYTS/ASTR 206 – Rings and Moons of Saturn 3 We can divide Saturn’s system into three main parts… The A-D ring zone Ring gaps and shepherd moons The E ring zone Ring supplies by Enceladus Tethys, Dione and Rhea have a lot of similarities The distant satellites Iapetus, Hyperion, Phoebe Linked together by exchange of material PYTS/ASTR 206 – Rings and Moons of Saturn 4 Discovery of Saturn’s Rings Discovered by Galileo Appearance in 1610 baffled him “…to my very great amazement Saturn was seen to me to be not a single star, but three together, which almost touch each other" It got more confusing… In 1612 the extra “stars” had disappeared “…I do not know what to say…" PYTS/ASTR 206 – Rings and Moons of Saturn 5 In 1616 the extra ‘stars’ were back Galileo’s telescope had improved He saw two “half-ellipses” He died in 1642 and never figured it out In the 1650s Huygens figured out that Saturn was surrounded by a flat disk The disk disappears when seen edge on He discovered Saturn’s
    [Show full text]
  • Spectropolarimetry of the Two Faces of Saturn's Moon Iapetus
    Spectropolarimetry of the two faces of Saturn’s moon Iapetus C. Ejeta1, H. Böhnhardt1, S. Bagnulo2, G. P. Tozzi3, K. Muinonen4 1. Max-Planck-Institut für Sonnensystemforschung, katlenburg-Lindau 2. Armagh Observatory, N. Ireland, UK 3. INAF – OSS. Astrofisico di Arcetri, Frienze, Italy 4. Department of Physics, University of Helsinki, Finland Outlines • Polarimetry of Galilean satellites of Jupiter • Iapetus Observing Program • Method of performing linear spectropolarimetry • Conclusions and Outlook Polarimetry of Galilean Satellites Mishchenko et al, 2010, in Polarimetric remote sensing of SSOs (book) Io: ==> has a surface of partly absorbing crystals believed to be resulted from evaporates released from mantle. ==> Pure water frost is not likely to be present. Europa: ==> has a water frost dominated surface. Ganymede: ==> has an alternating frosted areas, mostly composed of water, with interstitial dark terrain most probably of a rocky nature. Galilean Satellites --- Callisto Leading hemisphere: ==> covered mostly by a layer of pulverized rocks, of the “regolith” type . Trailing hemisphere: ==> covered mostly by rock or gravel free of fine regolithic powder . Rosenbush, Icarus, 2002 Polarimetry of Saturn’s B ring & Iapetus Rosenbush et al. JQSRT, 2006 Rosenbush et al., 2002, in Optics of cosmic dust (book) ==> deposits of aggregates and sub-micrometer-sized icy particles on its surface. Iapetus Iapetus Observing Program Western Bright Eastern Dark Date α (in deg.) Date α(in deg.) 2009/04/03 2.7 2009/05/13 5.7 2009/06/22 6.0 2010/01/11 5.7 2010/02/18 3.3 2010/03/30 0.9 2010/05/07 4.5 2010/06/16 6.1 2010/07/27 5.1 2011/02/14 4.6 2011/01/05 5.9 2011/05/03 3.0 2011/03/25 1.1 2011/07/21 5.8 2011/06/10 5.6 2011/12/31 5.5 2011/12/01 5.5 2012/03/19 2.9 2012/02/08 5.5 2012/06/05 4.7 2012/04/26 1.2 2012/08/24 4.8 2012/07/14 6.0 2013/02/02 5.7 2013/03/13 4.3 2013/04/22 0.7 2013/05/30 3.2 2013/07/09 5.6 2013/08/18 5.6 Method FORS2 at the ESO VLT Schematic concept of spectro-polarimetry Method….
    [Show full text]
  • The Habitability of Icy Exomoons
    University of Groningen Master thesis Astronomy The habitability of icy exomoons Supervisor: Author: Prof. Floris F.S. Van Der Tak Jesper N.K.Y. Tjoa Dr. Michael \Migo" Muller¨ June 27, 2019 Abstract We present surface illumination maps, tidal heating models and melting depth models for several icy Solar System moons and use these to discuss the potential subsurface habitability of exomoons. Small icy moons like Saturn's Enceladus may maintain oceans under their ice shells, heated by en- dogenic processes. Under the right circumstances, these environments might sustain extraterrestrial life. We investigate the influence of multiple orbital and physical characteristics of moons on the subsurface habitability of these bodies and model how the ice melting depth changes. Assuming a conduction only model, we derive an analytic expression for the melting depth dependent on seven- teen physical and orbital parameters of a hypothetical moon. We find that small to mid-sized icy satellites (Enceladus up to Uranus' Titania) locked in an orbital resonance and in relatively close orbits to their host planet are best suited to sustaining a subsurface habitable environment, and may do so largely irrespective of their host's distance from the parent star: endogenic heating is the primary key to habitable success, either by tidal heating or radiogenic processes. We also find that the circumplanetary habitable edge as formulated by Heller and Barnes (2013) might be better described as a manifold criterion, since the melting depth depends on seventeen (more or less) free parameters. We conclude that habitable exomoons, given the right physical characteristics, may be found at any orbit beyond the planetary habitable zone, rendering the habitable zone for moons (in principle) arbitrarily large.
    [Show full text]
  • Saturn's Moon Iapetus Is the Yin-Yang of the Solar System 13 September 2007
    Saturn's moon Iapetus is the yin-yang of the solar system 13 September 2007 Images returned late Tuesday and early Wednesday show a surface that is heavily cratered, along with the mountain ridge that runs along the moon's equator. Many of the close-up observations focused on studying the strange 20-km high mountain ridge that gives the moon a walnut- shaped appearance. "The images are really stunning," said Tilmann Denk, Cassini imaging scientist at the Free University in Berlin, Germany, who was responsible for the imaging observation planning. "Every new picture contained its own charm. I was most pleased about the images showing huge mountains rising over the horizon. I knew about this scenic viewing opportunity for more than seven years, and now the real images have suddenly materialised." This flyby was nearly 100 times closer to Iapetus than Cassini's 2004 flyby, bringing the spacecraft to Cassini zooms in, for the first time, on the patchy, bright about 1640 km from the surface. The moon's and dark mountains on Saturn's two-toned moon, irregular walnut shape, the mountain ridge that lies Iapetus. The mountains were originally identified in images from the NASA Voyager spacecraft taken more almost directly on the equator and Iapetus’ than 25 years earlier. The image was acquired during brightness contrast are among the key mysteries Cassini's only close flyby of Iapetus. The terrain seen scientists are trying to solve. here is located on the equator of Iapetus at approximately 199° West, in the transition region "There is never a dull moment on this mission," between the moon's bright and dark hemispheres.
    [Show full text]
  • Rotation Periods of Irregular Satellites of Saturn
    EPSC Abstracts Vol. 6, EPSC-DPS2011-1452, 2011 EPSC-DPS Joint Meeting 2011 c Author(s) 2011 Rotation Periods of Irregular Satellites of Saturn T. Denk (1), S. Mottola (2), Th. Roatsch (2), H. Rosenberg (1), and G. Neukum (1) (1) FU Berlin, Germany ([email protected]), (2) DLR Berlin, Germany Abstract ~60x to ~240x closer to the objects than the Earth is, and long duration observations are possible because Rotation periods of six irregular moons of Saturn there is no 24-h day/night cycle at Cassini. Dis- have been measured as follows: Siarnaq ~06:40 h; advantages are the relatively small telescope mirror Ymir ~07:20 h; Albiorix 13:19±0:08 h; Bebhionn of the Cassini ISS camera (0.17 m), the smaller field- ~16 h; Paaliaq ~19 h; Kiviuq 21:49±0:13 h (Tab. 1). of-view of the ISS resulting in a significantly higher pointing accuracy requirement, and the inability of doing image quality checks and exposure parameter 1. Introduction adaptations during data acquisition. We observe irregular moons of Saturn with the Imaging Experiment (ISS) of the Cassini spacecraft 2. Results [1]. Motivation is the determination of basic properties of these objects like rotation periods, polar Measured rotation periods for seven satellites are axes orientations, object sizes and shapes, phase shown in Tab. 1. The values vary significantly: curves, colors, or the search for binaries. This might While Siarnaq, with a period of ~6 h 40 min., rotates allow a better understanding of the impact history in relatively fast, Kiviuq needs almost 22 h for one the saturnian system including the question about the day/night cycle.
    [Show full text]
  • Iapetus' Geophysics: Rotation Rate, Shape, and Equatorial Ridge
    Icarus 190 (2007) 179–202 www.elsevier.com/locate/icarus Iapetus’ geophysics: Rotation rate, shape, and equatorial ridge J.C. Castillo-Rogez a,∗,D.L.Matsona,C.Sotina,b, T.V. Johnson a, J.I. Lunine c, P.C. Thomas d a Jet Propulsion Laboratory, California Institute of Technology, M/S 230-260, 4800 Oak Grove Drive, Pasadena, CA 91109, USA b UMR – CNRS 6112 Laboratoire de planétologie et géodynamique de Nantes, 2, rue de la Houssinière, 44322 Nantes Cedex 3, France c Lunar and Planetary Laboratory, 1629 E. University Blvd., Tucson, AZ 85721-0092, USA d Department of Astronomy, Cornell University, 422 Space Sciences Building, Ithaca, NY 14853, USA Received 23 July 2006; revised 30 January 2007 Available online 28 March 2007 Abstract Iapetus has preserved evidence that constrains the modeling of its geophysical history from the time of its accretion until now. The evidence is (a) its present 79.33-day rotation or spin rate, (b) its shape that corresponds to the equilibrium figure for a hydrostatic body rotating with a period of ∼16 h, and (c) its high, equatorial ridge, which is unique in the Solar System. This paper reports the results of an investigation into the coupling between Iapetus’ thermal and orbital evolution for a wide range of conditions including the spatial distributions with time of composition, porosity, short-lived radioactive isotopes (SLRI), and temperature. The thermal model uses conductive heat transfer with temperature-dependent conductivity. Only models with a thick lithosphere and an interior viscosity in the range of about the water ice melting point can explain the observed shape.
    [Show full text]
  • Cassini ISS Astrometry of the Saturnian Satellites: Tethys, Dione, Rhea, Iapetus, and Phoebe 2004–2012?
    A&A 575, A73 (2015) Astronomy DOI: 10.1051/0004-6361/201425605 & c ESO 2015 Astrophysics Cassini ISS astrometry of the Saturnian satellites: Tethys, Dione, Rhea, Iapetus, and Phoebe 2004–2012? R. Tajeddine1;2, V. Lainey1, N. J. Cooper3;1, and C. D. Murray3 1 IMCCE, Observatoire de Paris, UMR 8028 du CNRS, UPMC, Université de Lille 1, 77 av. Denfert-Rochereau, 75014 Paris, France 2 Department of Astronomy, Cornell University, 326 Space Sciences Building, Ithaca, NY 14853, USA e-mail: [email protected] 3 Astronomy Unit, Queen Mary University of London, Mile End Road, London E1 4NS, UK Received 31 December 2014 / Accepted 19 January 2015 ABSTRACT Context. The Cassini spacecraft has been orbiting Saturn since 2004 and has returned images of satellites with an astrometric resolu- tion as high as a few hundred meters per pixel. Aims. We used the images taken by the Narrow Angle Camera (NAC) of the Image Science Subsystem (ISS) instrument on board Cassini, for the purpose of astrometry. Methods. We applied the same method that was previously developed to reduce Cassini NAC images of Mimas and Enceladus. Results. We provide 5463 astrometric positions in right ascension and declination (α, δ) of the satellites: Tethys, Dione, Rhea, Iapetus, and Phoebe, using images that were taken by Cassini NAC between 2004 and 2012. the mean residuals compared to the JPL ephemeris SAT365 are of the order of hundreds of meters with standard deviations of the order of a few kilometers. The frequency analysis of the residuals shows the remaining unmodelled effects of satellites on the dynamics of other satellites.
    [Show full text]
  • Icy Satellite Cratering and Ages
    Chapter 19 Icy Satellites of Saturn: Impact Cratering and Age Determination Luke Dones, Clark R. Chapman, William B. McKinnon, H. Jay Melosh, Michelle R. Kirchoff, Gerhard Neukum, and Kevin J. Zahnle Abstract Saturn is the first giant planet to be visited by mechanism by which the entire Solar System might have an orbiting spacecraft that can transmit large amounts of experienced an era of heavy bombardment long after the data to Earth. Crater counts on satellites from Phoebe in- planets formed. We then discuss the three cratering chronolo- ward to the regular satellites and ring moons are providing gies, including one based upon the Nice model, that have unprecedented insights into the origin and time histories of been used to infer surface ages from crater densities on the impacting populations. Many Voyager-era scientists con- the saturnian satellites. After reviewing scaling relations be- cluded that the satellites had been struck by at least two tween the properties of impactors and the craters they pro- populations of impactors. In this view, the Population I im- duce, we provide model estimates of the present-day rate at pactors, which were generally judged to be “comets” orbiting which comets impact, and catastrophically disrupt, the satur- the Sun, formed most of the larger and older craters, while nian moons. Finally, we present crater counts on the satellites Population II impactors, interpreted as Saturn-orbiting ejecta from two different groups. Many of the heavily cratered ter- from impacts on satellites, produced most of the smaller rains appear to be nearly saturated, so it is difficult to infer and younger craters.
    [Show full text]
  • Cassini Small Bodies Observations
    Cassini Small Bodies Observations Ymir Atlas Tilmann Denk Freie Universität Berlin, Germany 10th Small Bodies Assessment Group Meeting (SBAG) Washington, DC – Thu 09 Jan 2014 2:20 p.m. EST (8:20 p.m. CET) T.D. gratefully acknowledges the support of this research by the Deutsches Zentrum für Luft- und Raumfahrt (DLR) in Bonn (Germany) (grant no.: 50 OH 1102). Cassini Orbiter Remote Sensing (ORS) • Imaging (ISS NAC, WAC) • Vis./near-IR spectrometer (VIMS) • IR spectrometer (CIRS) • UV spectrometer (UVIS) ORS FOVs: = 3.5° = 0.35° Denk -- Cassini Small Bodies Observations – page 2 Small Bodies or "Rocks" of Saturn "Alkyonides" 3 38 "Irregulars" "Ring rocks", 9 • Methone, Anthe, Pallene • Phoebe, Siarnaq, Albiorix, "Sheperds", Paaliaq, Ymir, Kiviuq, "Co-orbitals" Orbits between Mimas • Tarvos, Ijiraq, Erriapus, and Enceladus Skathi, Hyrrokkin, Suttungr, • Pan, Daphnis, Atlas Prometheus, Pandora Mundilfari, Thrymr, Narvi, • Discovered by Cassini etc. Janus, Epimetheus Bestla, Kari, Tarqeq, Aegaeon • Beyond 11 million km (> 180 R ) • Inside Mimas orbit; 4 "Lagrange Moons" S partly inside A ring or "Trojans" • 9 prograde, 29 retrograde • Cassini: disk-resolved • Telesto, Calypso • Discovered from Earth & spectra Helene, Polydeuces • Cassini: only disk-integrated • L4 & L5 moons of (except Phoebe) Tethys, Dione Denk -- Cassini Small Bodies Observations – page 3 "Ring rocks" Pan, Daphnis Denk -- Cassini Small Bodies Observations – page 4 "Ring rocks" Pan Daphnis Atlas 34 x 21 km 9 x 6 km 41 x 19 km Denk -- Cassini Small Bodies Observations – page
    [Show full text]
  • Search for Life on the Moons of Saturn
    Search for Life on the Moons of Saturn Leonie Schunk Mikko Pöntinen Planetary exploration, Autumn 2017 University of Helsinki Lecturer: Tomas Kohout Course assistant: Juulia-Gabrielle Moreau Search for life on the moons of Saturn Table of Contents 1. Introduction 3 2. Parameters for a habitable environment 5 3. Life conditions on the moons 7 Enceladus 9 Dione 9 Titan 10 4. Evaluation of geological maps of the moons 11 Maps of Enceladus 11 Map of Dione 12 Maps of Titan 13 Map of Mimas 14 Map of Tethys 14 Map of Rhea 15 Map of Iapetus 15 5. Detecting life 16 6. Prospects of a successful mission to different moons 20 7. Mission options and instrumentation 21 8. Preliminary mission plan 23 9. Conclusions 24 References 25 2 1. Introduction In 1997 a spacecraft, including a probe from NASA (this was a flagship project from NASA) and a lander from ESA, was launched to study Saturn and its system. This Cassini-Huygens mission was the first one to enter its orbit and only the fourth one that was sent to visit the planet. It spent 13 years orbiting Saturn, after a transit which took around seven years with four gravity assists on Earth, Venus and Jupiter, and a flyby of asteroid 2685 Masursky. The mission ended in September 2017, when Cassini burned up in Saturn’s atmosphere. The Huygens lander was able to land on Saturn’s biggest moon Titan on January 14th 2005 with a parachute, which was very unique since it was the first time a landing on a moon other than our own was successful.
    [Show full text]