The Exploration of Titan with an Orbiter and a Lake Probe
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Cassini Update
Cassini Update Dr. Linda Spilker Cassini Project Scientist Outer Planets Assessment Group 22 February 2017 Sols%ce Mission Inclina%on Profile equator Saturn wrt Inclination 22 February 2017 LJS-3 Year 3 Key Flybys Since Aug. 2016 OPAG T124 – Titan flyby (1584 km) • November 13, 2016 • LAST Radio Science flyby • One of only two (cf. T106) ideal bistatic observations capturing Titan’s Northern Seas • First and only bistatic observation of Punga Mare • Western Kraken Mare not explored by RSS before T125 – Titan flyby (3158 km) • November 29, 2016 • LAST Optical Remote Sensing targeted flyby • VIMS high-resolution map of the North Pole looking for variations at and around the seas and lakes. • CIRS last opportunity for vertical profile determination of gases (e.g. water, aerosols) • UVIS limb viewing opportunity at the highest spatial resolution available outside of occultations 22 February 2017 4 Interior of Hexagon Turning “Less Blue” • Bluish to golden haze results from increased production of photochemical hazes as north pole approaches summer solstice. • Hexagon acts as a barrier that prevents haze particles outside hexagon from migrating inward. • 5 Refracting Atmosphere Saturn's• 22unlit February rings appear 2017 to bend as they pass behind the planet’s darkened limb due• 6 to refraction by Saturn's upper atmosphere. (Resolution 5 km/pixel) Dione Harbors A Subsurface Ocean Researchers at the Royal Observatory of Belgium reanalyzed Cassini RSS gravity data• 7 of Dione and predict a crust 100 km thick with a global ocean 10’s of km deep. Titan’s Summer Clouds Pose a Mystery Why would clouds on Titan be visible in VIMS images, but not in ISS images? ISS ISS VIMS High, thin cirrus clouds that are optically thicker than Titan’s atmospheric haze at longer VIMS wavelengths,• 22 February but optically 2017 thinner than the haze at shorter ISS wavelengths, could be• 8 detected by VIMS while simultaneously lost in the haze to ISS. -
Titan North Pole
. Melrhir Lacuna . Ngami Lacuna . Cardiel Lacus . Jerid Lacuna . Racetrack Lacuna . Uyuni Lacuna Vänern Freeman. Lanao . Lacus . Atacama Lacuna Lacus Lacus . Sevan Lacus Ohrid . Cayuga Lacus .Albano Lacus Lacus Logtak . .Junín Lacus . Lacus . Mweru Lacus . Prespa Lacus Eyre . Taupo Lacus . Van Lacus en Lacuna Suwa Lacus m Ypoa Lacus. lu . F Rukwa Lacus Winnipeg . Atitlán Lacus . Viedma Lacus . Rannoch Lacus Ihotry Lacus Lacus n .Phewa Lacus . o h . Chilwa Lacus i G Patos Maracaibo Lacus . Oneida Lacus Rombaken . Sinus Muzhwi Lacus Negra Lacus . Mývatn Lacus Sinus . Buada Lacus. Uvs Lacus Lagdo Lacus . Annecy Lacus . Dilolo Lacus Towada Lacus Dridzis Lacus . Vid Flumina Imogene Lacus . Arala Lacus Yessey Lacus Woytchugga Lacuna . Toba Lacus . .Olomega Lacus Zaza Lacus . Roca Lacus Müggel Buyan . Waikare Lacus . Insula Nicoya Rwegura Lacus . Quilotoa Lacus . Lacus . Tengiz Lacus Bralgu Ligeia Planctae Insulae Sinus Insulae Zub Lacus . Grasmere Lacus Puget XanthusSinus Flumen Hlawga Lacus . Mare Kokytos Flumina . Kutch Lacuna Mackay S Lithui Montes . a m Kivu Lacus Ginaz T Nakuru Lacuna Lacus Fogo Lacus . r . b e a tio v Niushe n i F Labyrinthus Wakasa z lum e i Letas Lacus na Sinus . Balaton Lacus Layrinthus F r e t u m . Karakul Lacus Ipyr Labyrinthus a Flu Xolotlán ay m . noh u en . a Lacus Sparrow Lacus p Moray A Okahu .Akema Lacus Sinus Sinus Trichonida .Brienz Lacus Meropis Insula . Lacus Qinghai Hawaiki . Insulae Onogoro Lacus Punga Insula Fundy Sinus Tumaco Synevyr Sinus . Mare Fagaloa Lacus Sinus Tunu s Saldanha u Sinus n Sinus i S a h c a v Trold Yojoa A . Lacus Neagh Kraken MareSinus Feia s Lacus u in Mayda S Lacus Insula Dingle Sinus Gamont Gen a Gabes Sinus . -
Cassini RADAR Images at Hotei Arcus and Western Xanadu, Titan: Evidence for Geologically Recent Cryovolcanic Activity S
GEOPHYSICAL RESEARCH LETTERS, VOL. 36, L04203, doi:10.1029/2008GL036415, 2009 Click Here for Full Article Cassini RADAR images at Hotei Arcus and western Xanadu, Titan: Evidence for geologically recent cryovolcanic activity S. D. Wall,1 R. M. Lopes,1 E. R. Stofan,2 C. A. Wood,3 J. L. Radebaugh,4 S. M. Ho¨rst,5 B. W. Stiles,1 R. M. Nelson,1 L. W. Kamp,1 M. A. Janssen,1 R. D. Lorenz,6 J. I. Lunine,5 T. G. Farr,1 G. Mitri,1 P. Paillou,7 F. Paganelli,2 and K. L. Mitchell1 Received 21 October 2008; revised 5 January 2009; accepted 8 January 2009; published 24 February 2009. [1] Images obtained by the Cassini Titan Radar Mapper retention age comparable with Earth or Venus (500 Myr) (RADAR) reveal lobate, flowlike features in the Hotei [Lorenz et al., 2007]). Arcus region that embay and cover surrounding terrains and [4] Most putative cryovolcanic features are located at mid channels. We conclude that they are cryovolcanic lava flows to high northern latitudes [Elachi et al., 2005; Lopes et al., younger than surrounding terrain, although we cannot reject 2007]. They are characterized by lobate boundaries and the sedimentary alternative. Their appearance is grossly relatively uniform radar properties, with flow features similar to another region in western Xanadu and unlike most brighter than their surroundings. Cryovolcanic flows are of the other volcanic regions on Titan. Both regions quite limited in area compared to the more extensive dune correspond to those identified by Cassini’s Visual and fields [Radebaugh et al., 2008] or lakes [Hayes et al., Infrared Mapping Spectrometer (VIMS) as having variable 2008]. -
Appendix 1: Venus Missions
Appendix 1: Venus Missions Sputnik 7 (USSR) Launch 02/04/1961 First attempted Venus atmosphere craft; upper stage failed to leave Earth orbit Venera 1 (USSR) Launch 02/12/1961 First attempted flyby; contact lost en route Mariner 1 (US) Launch 07/22/1961 Attempted flyby; launch failure Sputnik 19 (USSR) Launch 08/25/1962 Attempted flyby, stranded in Earth orbit Mariner 2 (US) Launch 08/27/1962 First successful Venus flyby Sputnik 20 (USSR) Launch 09/01/1962 Attempted flyby, upper stage failure Sputnik 21 (USSR) Launch 09/12/1962 Attempted flyby, upper stage failure Cosmos 21 (USSR) Launch 11/11/1963 Possible Venera engineering test flight or attempted flyby Venera 1964A (USSR) Launch 02/19/1964 Attempted flyby, launch failure Venera 1964B (USSR) Launch 03/01/1964 Attempted flyby, launch failure Cosmos 27 (USSR) Launch 03/27/1964 Attempted flyby, upper stage failure Zond 1 (USSR) Launch 04/02/1964 Venus flyby, contact lost May 14; flyby July 14 Venera 2 (USSR) Launch 11/12/1965 Venus flyby, contact lost en route Venera 3 (USSR) Launch 11/16/1965 Venus lander, contact lost en route, first Venus impact March 1, 1966 Cosmos 96 (USSR) Launch 11/23/1965 Possible attempted landing, craft fragmented in Earth orbit Venera 1965A (USSR) Launch 11/23/1965 Flyby attempt (launch failure) Venera 4 (USSR) Launch 06/12/1967 Successful atmospheric probe, arrived at Venus 10/18/1967 Mariner 5 (US) Launch 06/14/1967 Successful flyby 10/19/1967 Cosmos 167 (USSR) Launch 06/17/1967 Attempted atmospheric probe, stranded in Earth orbit Venera 5 (USSR) Launch 01/05/1969 Returned atmospheric data for 53 min on 05/16/1969 M. -
Catherinesaunders
The Utility of Robot Sensory Devices in a Collaborative Autonomic Environment Catherine Saunders, Roy Sterritt, George Wilkie School of Computing and Mathematics University of Ulster Northern Ireland [email protected], [email protected], [email protected] Abstract –-This paper proposes an Autonomic architecture that environment and relay meaningful information to each will enable mobile robots to self-manage and collaborate by other. using control loops to monitor their internal state and external environment. The Autonomic Computing MAPE-K control In this paper we discuss the sensor capabilities of the Dr loop is used to design a Robot Autonomic Element and a Robot X80-H platform that will be used for the research. A Mapping Autonomic Element; each can exchange data and collaborate to find an object located within a room. A review of design of the proposed system is included and explained. A the sensor capabilities of the X80-H mobile robot platform is brief literature review of robotic collaborative systems is undertaken with emphasis on how useful each sensor will be to also included. The Research Background section looks at the proposed research. A literature review of other projects why self-managing software systems are needed. that feature robot collaboration is also included. Keywords - autonomic computing; mobile robot; Dr Robot II. ROBOT SENSORY DEVICES X80-H; collaboration; MAPE-K This section gives an overview of the sensors that the Dr Robot X80-H is equipped with. We assess how reliable they are and how useful they will be for our research. We will be I. -
Comparative Saturn-Versus-Jupiter Tether Operation
Journal of Geophysical Research: Space Physics Comparative Saturn-Versus-Jupiter Tether Operation J. R. Sanmartin1 ©, J. Pelaez1 ©, and I. Carrera-Calvo1 Abstract Saturn, Uranus, and Neptune, among the four Giant Outer planets, have magnetic field B about 20 times weaker than Jupiter. This could suggest, in principle, that planetary capture and operation using tethers, which involve B effects twice, might be much less effective at Saturn, in particular, than at Jupiter. It was recently found, however, that the very high Jovian B itself strongly limits conditions for tether use, maximum captured spacecraft-to-tether mass ratio only reaching to about 3.5. Further, it is here shown that planetary parameters and low magnetic field might make tether operation at Saturn more effective than at Jupiter. Operation analysis involves electron plasma density in a limited radial range, about 1-1.5 times Saturn radius, and is weakly requiring as regards density modeling. 1. Introduction All Giant Outer planets have magnetic field B and corotating plasma, allowing nonconventional exploration. Electrodynamic tethers, which are thermodynamic (dissipative) in character, can 1. provide propellantless drag both for deorbiting spacecraft in Low Earth Orbit at end of mission and for planetary spacecraft capture and operation down the gravitational well, and 2. generate accompanying, useful electrical power, or store it to later invert tether current (Sanmartin et al., 1993; Sanmartin & Estes, 1999). At Jupiter, tethers could be effective because its field B is high (Sanmartin et al., 2008). Tethers would allow a variety of science applications (Sanchez-Torres & Sanmartin, 2011). The Saturn field is 20 times smaller, however, and tether operation involves field B twice, which makes that thermodynamic character manifest: 1. -
Titan's Near Infrared Atmospheric Transmission and Surface
40th Lunar and Planetary Science Conference (2009) 1863.pdf TITAN’S NEAR INFRARED ATMOSPHERIC TRANSMISSION AND SURFACE REFLECTANCE FROM THE CASSINI VISUAL AND INFRARED MAPPING SPECTROMETER. P. Hayne1,2 and T. B. McCord2, J. W. Barnes3, 1University of California, Los Angeles (595 Charles Young Drive East, Los Angeles, CA 90095; [email protected]), 2The Bear Fight Center (Winthrop, WA), 3University of Idaho (Moscow, ID). 1. Introduction: Titan’s near infrared spectrum is At the top of the atmosphere, the outgoing intensity is dominated by absorption by atmospheric methane. then Direct transmission of radiation from the surface ⎛ A 1 ⎞ (1) I↑ / I= A ⋅ e −τ(1/ μ1 + 1/ μ 2 ) +β ⋅ ⎜ e −τ/ μ1 + ⎟ through the full atmosphere is nearly zero, except in top 0 ⎜ μ μ ⎟ several methane “windows”. In these narrow spectral ⎝ 1 2 ⎠ regions, Titan’s surface is visible, but our view is akin where A is the (monochromatic) surface albedo, β ≡ to peering through a dirty window pane, due to both Γ/I0 is the ratio of the diffuse emergent intensity to the direct incident intensity at the top of the atmosphere, N2-induced pressure broadening of adjacent CH4 lines and multiple scattering by stratospheric haze particles. and μ2 is the cosine of the emergence angle. To solve Measured reflectance values in the methane windows Equation (1), we make an initial guess τ for the total are therefore only partially representative of true sur- optical depth, so that face albedo. ⎡ ⎛ A 1 ⎞⎤ (2) τ≈ − μ′lnII / −β ⋅⎜ ⋅e −τ/ μ1 + ⎟ + μ′ln A Using a simple radia- ⎢ 0 ⎜ ⎟⎥ ⎣ ⎝ μ1 μ 2 ⎠⎦ tive transfer model, we where μ′ ≡ /1 ( 1+ 1 ). -
Transient Broad Specular Reflections from Titan's North Pole
Lunar and Planetary Science XLVIII (2017) 1519.pdf TRANSIENT BROAD SPECULAR REFLECTIONS FROM TITAN’S NORTH POLE Rajani Dhingra1, J. W. Barnes1, R. H. Brown2, B J. Buratti3, C. Sotin3, P. D. Nicholson4, K. H. Baines5, R. N. Clark6, J. M. Soderblom7, Ralph Jaumann8, Sebastien Rodriguez9 and Stéphane Le Mouélic10 1Dept. of Physics, University of Idaho, ID,USA, [email protected], 2Dept. of Planetary Sciences, University of Arizona, AZ, USA, 3JPL, Caltech, CA, USA, 4Cornell University, Astronomy Dept., NY, USA, 5Space Science & Engineering Center, University of Wisconsin- Madison, 1225 West Dayton St., WI, USA, 6Planetary Science Institute, Arizona, USA, 7Dept. of Earth, Atmospheric and Planetary Sciences, MIT, Cambridge, USA, 8Deutsches Zentrum für Luft- und Raumfahrt, 12489, Germany, 9Laboratoire AIM, Centre d’etude de Saclay, DAPNIA/Sap, Centre de lorme des Merisiers, 91191 Gif/Yvette, France, 10Laboratoire de Planetologie et Geodynamique, CNRS UMR6112, Universite de Nantes, France. Introduction: The recent Cassini VIMS (Visual and Infrared Mapping Spectrometer) T120 observation of Titan show extensive north polar surface features which might correspond to a broad, off-specular reflec- tion from a wet, rough, solid surface. The observation appears similar in spectral nature to previous specular reflection observations and also has the appropriate geometry. Figure 1 illustrates the geometry of specular reflection from Jingpo Lacus [1], waves from Punga Mare [2] and T120 observation of broad off-specular reflection from land surfaces. We observe specular reflections apart from the observation of broad specular reflection and extensive clouds in the T120 flyby. Our initial mapping shows that the off-specular re- flections occur only over land surfaces. -
Titan and the Moons of Saturn Telesto Titan
The Icy Moons and the Extended Habitable Zone Europa Interior Models Other Types of Habitable Zones Water requires heat and pressure to remain stable as a liquid Extended Habitable Zones • You do not need sunlight. • You do need liquid water • You do need an energy source. Saturn and its Satellites • Saturn is nearly twice as far from the Sun as Jupiter • Saturn gets ~30% of Jupiter’s sunlight: It is commensurately colder Prometheus • Saturn has 82 known satellites (plus the rings) • 7 major • 27 regular • 4 Trojan • 55 irregular • Others in rings Titan • Titan is nearly as large as Ganymede Titan and the Moons of Saturn Telesto Titan Prometheus Dione Titan Janus Pandora Enceladus Mimas Rhea Pan • . • . Titan The second-largest moon in the Solar System The only moon with a substantial atmosphere 90% N2 + CH4, Ar, C2H6, C3H8, C2H2, HCN, CO2 Equilibrium Temperatures 2 1/4 Recall that TEQ ~ (L*/d ) Planet Distance (au) TEQ (K) Mercury 0.38 400 Venus 0.72 291 Earth 1.00 247 Mars 1.52 200 Jupiter 5.20 108 Saturn 9.53 80 Uranus 19.2 56 Neptune 30.1 45 The Atmosphere of Titan Pressure: 1.5 bars Temperature: 95 K Condensation sequence: • Jovian Moons: H2O ice • Saturnian Moons: NH3, CH4 2NH3 + sunlight è N2 + 3H2 CH4 + sunlight è CH, CH2 Implications of Methane Free CH4 requires replenishment • Liquid methane on the surface? Hazy atmosphere/clouds may suggest methane/ ethane precipitation. The freezing points of CH4 and C2H6 are 91 and 92K, respectively. (Titan has a mean temperature of 95K) (Liquid natural gas anyone?) This atmosphere may resemble the primordial terrestrial atmosphere. -
(Preprint) AAS 18-416 PRELIMINARY INTERPLANETARY MISSION
(Preprint) AAS 18-416 PRELIMINARY INTERPLANETARY MISSION DESIGN AND NAVIGATION FOR THE DRAGONFLY NEW FRONTIERS MISSION CONCEPT Christopher J. Scott,∗ Martin T. Ozimek,∗ Douglas S. Adams,y Ralph D. Lorenz,z Shyam Bhaskaran,x Rodica Ionasescu,{ Mark Jesick,{ and Frank E. Laipert{ Dragonfly is one of two mission concepts selected in December 2017 to advance into Phase A of NASA’s New Frontiers competition. Dragonfly would address the Ocean Worlds mis- sion theme by investigating Titan’s habitability and prebiotic chemistry and searching for evidence of chemical biosignatures of past (or extant) life. A rotorcraft lander, Dragonfly would capitalize on Titan’s dense atmosphere to enable mobility and sample materials from a variety of geologic settings. This paper describes Dragonfly’s baseline mission design giv- ing a complete picture of the inherent tradespace and outlines the design process from launch to atmospheric entry. INTRODUCTION Hosting the moons Titan and Enceladus, the Saturnian system contains at least two unique destinations that have been classified as ocean worlds. Titan, the second largest moon in the solar system behind Ganymede and the only planetary satellite with a significant atmosphere, is larger than the planet Mercury at 5,150 km (3,200 miles) in diameter. Its atmosphere, approximately 10 times the column mass of Earth’s, is composed of 95% nitrogen, 5% methane, 0.1% hydrogen along with trace amounts of organics.1 Titan’s atmosphere may resemble that of the Earth before biological processes began modifying its composition. Similar to the hydrological cycle on Earth, Titan’s methane evaporates into clouds, rains, and flows over the surface to fill lakes and seas, and subsequently evaporates back into the atmosphere. -
Surface of Ligeia Mare, Titan, from Cassini Altimeter and Radiometer Analysis Howard Zebker, Alex Hayes, Mike Janssen, Alice Le Gall, Ralph Lorenz, Lauren Wye
Surface of Ligeia Mare, Titan, from Cassini altimeter and radiometer analysis Howard Zebker, Alex Hayes, Mike Janssen, Alice Le Gall, Ralph Lorenz, Lauren Wye To cite this version: Howard Zebker, Alex Hayes, Mike Janssen, Alice Le Gall, Ralph Lorenz, et al.. Surface of Ligeia Mare, Titan, from Cassini altimeter and radiometer analysis. Geophysical Research Letters, American Geophysical Union, 2014, 41 (2), pp.308-313. 10.1002/2013GL058877. hal-00926152 HAL Id: hal-00926152 https://hal.archives-ouvertes.fr/hal-00926152 Submitted on 19 Jul 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. PUBLICATIONS Geophysical Research Letters RESEARCH LETTER Surface of Ligeia Mare, Titan, from Cassini 10.1002/2013GL058877 altimeter and radiometer analysis Key Points: Howard Zebker1, Alex Hayes2, Mike Janssen3, Alice Le Gall4, Ralph Lorenz5, and Lauren Wye6 • Ligeia Mare, like Ontario Lacus, is flat with no evidence of ocean waves or wind 1Departments of Geophysics and Electrical Engineering, Stanford University, Stanford, California, USA, 2Department of • The -
Based Observations of Titan During the Huygens Mission Olivier Witasse,1 Jean-Pierre Lebreton,1 Michael K
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, E07S01, doi:10.1029/2005JE002640, 2006 Overview of the coordinated ground-based observations of Titan during the Huygens mission Olivier Witasse,1 Jean-Pierre Lebreton,1 Michael K. Bird,2 Robindro Dutta-Roy,2 William M. Folkner,3 Robert A. Preston,3 Sami W. Asmar,3 Leonid I. Gurvits,4 Sergei V. Pogrebenko,4 Ian M. Avruch,4 Robert M. Campbell,4 Hayley E. Bignall,4 Michael A. Garrett,4 Huib Jan van Langevelde,4 Stephen M. Parsley,4 Cormac Reynolds,4 Arpad Szomoru,4 John E. Reynolds,5 Chris J. Phillips,5 Robert J. Sault,5 Anastasios K. Tzioumis,5 Frank Ghigo,6 Glen Langston,6 Walter Brisken,7 Jonathan D. Romney,7 Ari Mujunen,8 Jouko Ritakari,8 Steven J. Tingay,9 Richard G. Dodson,10 C. G. M. van’t Klooster,11 Thierry Blancquaert,11 Athena Coustenis,12 Eric Gendron,12 Bruno Sicardy,12 Mathieu Hirtzig,12,13 David Luz,12,14 Alberto Negrao,12,14 Theodor Kostiuk,15 Timothy A. Livengood,16,15 Markus Hartung,17 Imke de Pater,18 Mate A´ da´mkovics,18 Ralph D. Lorenz,19 Henry Roe,20 Emily Schaller,20 Michael Brown,20 Antonin H. Bouchez,21 Chad A. Trujillo,22 Bonnie J. Buratti,3 Lise Caillault,23 Thierry Magin,23 Anne Bourdon,23 and Christophe Laux23 Received 17 November 2005; revised 29 March 2006; accepted 24 April 2006; published 27 July 2006. [1] Coordinated ground-based observations of Titan were performed around or during the Huygens atmospheric probe mission at Titan on 14 January 2005, connecting the momentary in situ observations by the probe with the synoptic coverage provided by continuing ground-based programs.