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Astronomy 330 HW 2 Presentations Outline
Astronomy 330 HW 2 •! Stanley Swat This class (Lecture 12): http://www.ufohowto.com/ Life in the Solar System •! Lucas Guthrie Next Class: http://www.crystalinks.com/abduction.html Life in the Solar System HW 5 is due Wednesday Music: We Are All Made of Stars– Moby Presentations Outline •! Daniel Borup •! Life on Venus? Futurama •! Life on Mars? Life in the Solar System? Earth – Venus comparison •! We want to examine in more detail the backyard of humans. •! What we find may change our estimates of ne. Radius 0.95 Earth Surface gravity 0.91 Earth Venus is the hottest Mass 0.81 Earth planet, the closest in Distance from Sun 0.72 AU size to Earth, the closest Average Temp 475 C in distance to Earth, and Year 224.7 Earth days the planet with the Length of Day 116.8 Earth days longest day. Atmosphere 96% CO2 What We Used to Think Turns Out that Venus is Hell Venus must be hotter, as it is closer the Sun, but the cloud •! The surface is hot enough to melt lead cover must reflect back a large amount of the heat. •! There is a runaway greenhouse effect •! There is almost no water In 1918, a Swedish chemist and Nobel laureate concluded: •! There is sulfuric acid rain •! Everything on Venus is dripping wet. •! Most of the surface is no doubt covered with swamps. •! Not a place to visit for Spring Break. •! The constantly uniform climatic conditions result in an entire absence of adaptation to changing exterior conditions. •! Only low forms of life are therefore represented, mostly no doubt, belonging to the vegetable kingdom; and the organisms are nearly of the same kind all over the planet. -
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. -
Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur
Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur To cite this version: Alex Soumbatov-Gur. Phobos, Deimos: Formation and Evolution. [Research Report] Karpov institute of physical chemistry. 2019. hal-02147461 HAL Id: hal-02147461 https://hal.archives-ouvertes.fr/hal-02147461 Submitted on 4 Jun 2019 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. Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur The moons are confirmed to be ejected parts of Mars’ crust. After explosive throwing out as cone-like rocks they plastically evolved with density decays and materials transformations. Their expansion evolutions were accompanied by global ruptures and small scale rock ejections with concurrent crater formations. The scenario reconciles orbital and physical parameters of the moons. It coherently explains dozens of their properties including spectra, appearances, size differences, crater locations, fracture symmetries, orbits, evolution trends, geologic activity, Phobos’ grooves, mechanism of their origin, etc. The ejective approach is also discussed in the context of observational data on near-Earth asteroids, main belt asteroids Steins, Vesta, and Mars. The approach incorporates known fission mechanism of formation of miniature asteroids, logically accounts for its outliers, and naturally explains formations of small celestial bodies of various sizes. -
Current State of Knowledge of the Magnetospheres of Uranus and Neptune
Current State of Knowledge of the Magnetospheres of Uranus and Neptune 28 July 2014 Abigail Rymer [email protected] What does a ‘normal’ magnetosphere look like? . N-S dipole field perpendicular to SW . Solar wind driven circulation system . Well defined central tail plasmasheet . Loaded flux tubes lost via substorm activity . Trapped radiation on closed (dipolar) field lines close to the planet. …but then what is normal…. Mercury Not entirely at the mercy of the solar wind after all . Jupiter . More like its own little solar system . Sub-storm activity maybe totally internally driven …but then what is normal…. Saturn Krimigis et al., 2007 What is an ice giant (as distinct from a gas giant) planet? Consequenses for the magnetic field Soderlund et al., 2012 Consequenses for the magnetic field Herbert et al., 2009 Are Neptune and Uranus the same? URANUS NEPTUNE Equatorial radius 25 559 km 24 622 km Mass 14.5 ME 17.14 ME Sidereal spin period 17h12m36s (retrograde) 16h6m36s Obliquity (axial tilt to ecliptic) -97.77º 28.32 Semi-major axis 19.2 AU 30.1 AU Orbital period 84.3 Earth years 164.8 Earth years Dipole moment 50 ME 25 ME Magnetic field Highly complex with a surface Highly complex with a surface field up to 110 000 nT field up to 60 000 nT Dipole tilt -59º -47 Natural satellites 27 (9 irregular) 14 (inc Triton at 14.4 RN) Spacecraft at Uranus and Neptune – Voyager 2 Voyager 2 observations - Uranus Stone et al., 1986 Voyager 2 observations - Uranus Voyager 2 made excellent plasma measurements with PLS, a Faraday cup type instrument. -
Solar Illumination Conditions at 4 Vesta: Predictions Using the Digital Elevation Model Derived from Hst Images
42nd Lunar and Planetary Science Conference (2011) 2506.pdf SOLAR ILLUMINATION CONDITIONS AT 4 VESTA: PREDICTIONS USING THE DIGITAL ELEVATION MODEL DERIVED FROM HST IMAGES. T. J. Stubbs 1,2,3 and Y. Wang 1,2,3 , 1Goddard Earth Science and Technology Center, University of Maryland, Baltimore County, Baltimore, MD, USA, 2NASA Goddard Space Flight Center, Greenbelt, MD, USA, 3NASA Lunar Science Institute, Ames Research Center, Moffett Field, CA, USA. Corresponding email address: Timothy.J.Stubbs[at]NASA.gov . Introduction: As with other airless bodies in the plane), the longitude of the ascending node is 103.91° Solar System, the surface of 4 Vesta is directly exposed and the argument of perihelion is 149.83°. Based on to the full solar spectrum. The degree of solar illumina- current estimates, Vesta’s orbital plane is believed to tion plays a major role in processes at the surface, in- have a precession period of 81,730 years [6]. cluding heating (surface temperature), space weather- For the shape of Vesta we use the 5 × 5° DEM ing, surface charging, surface chemistry, and exo- based on HST images [5], which is publicly available spheric production via photon-stimulated desorption. from the Planetary Data System (PDS). To our knowl- The characterization of these processes is important for edge, this is the best DEM of Vesta currently available. interepreting various surface properties. It is likely that The orbital information for Vesta is obtained from the solar illumination also controls the transport and depo- Dawn SPICE kernel, which currently limits us to the sition of volatiles at Vesta, as has been proposed at the current epoch (1900 to present). -
The Moon (~1700Km) an Asteroid (~50Km)
1) inventory Solar System 2) spin/orbit/shape 3) heated by the Sun overview 4) how do we fnd out Inventory 1 star (99.9% of M) 8 planets (99.9% of L) - Terrestrial: Mercury Venus Earth Mars - Giant: Jupiter Saturn Uranus Neptune Lots of small bodies incl. dwarf planets Ceres Pluto Eris Maybe a 9th planet? Moons of Jupiter Inventory (cont'd) 4 Galilean satellites (Ganymede, Callisto, Io & Europa), 3 Many moons & rings ~10 km (close to Jupiter, likely primordial) Mercury: 0 Venus: 0 Earth: 1 (1700km) Mars: 2 (~10km) Jupiter: 69 + rings Saturn: 62 + rings Uranus: 27 + rings Neptune: 14 + rings 2001J3: 4km Even among dwarf planets, asteroids, Kuiper belt objects, and comets. E.g., Pluto: 5 Eris: 1 Moons of Mars: Deimos & Phobos, ~10km Atmosphere no thick thick little thick Inventory (cont'd) ~105 known small objects in the - Asteroid belt (Ceres ~300 km) - Kuiper belt (Eris, Pluto, Sedna, Quaoar, ~1000 km) Estimated: ~1012 comets in the - Oort cloud (~ 104 AU) Associated: - zodiacal dust (fre-works on the sky: comets & meteorites) What are planets? IAU (for solar system): Orbits Sun, massive enough to be round and to have cleared its neighbourhood. More general: 6 1) no nuclear fusion (not even deuterium): Tc < 10 K 2) pressure provided by electron degeneracy and/or Coulomb force (l ~ h/p ~ d) (d ~ atomic radius) 3) can be solid or gaseous (with solid cores) --- similar density Mass & Mean r M [g/cm3] R~M J Jupiter 1.0 1.33 R R~M1/3 Saturn 0.3 0.77 R~M-1/3 Neptune 0.05 1.67 Uranus 0.04 1.24 Earth 0.003 5.52 Venus 0.002 5.25 planets brown dwarfs stars Mars 0.0003 3.93 Mercury 0.0002 5.43 3 MJ 13 MJ 80 MJ M Orbits inclination: largely coplanar (history) direction: all the same eccentricity: a few percent (except for Mercury) Titus-Bode (ftting) law (1766) planetary orbits appear to (almost) satisfy a single relation 'Predict' the existence of the asteroid belt (1801: Ceres discovered) coincidence or something deeper? other systems? Computer simulations indicate that planets are as maximally packed as allowed by stability. -
"Is There Life on Venus?" Pdf File
Home / Space / Specials Is there life on Venus? We call them "Martians" because, in science fiction, Mars has always been the natural home of extraterrestrials. In fact, of all the planets in the solar system, Mars is the prime candidate to host life, after Earth, of course. Indeed, Mars is on the outer edge of the habitable zone, that area around the Sun that delimits the space where the temperature is low enough to ensure that the water remains in a liquid state. And where there's water, it is well known, there's probably life. Yet it's cold on Mars today, and so far, all the probes and rovers we have sent to the surface of the red planet have found no signs of life. Planet Venus At the opposite end of the habitable belt there is Venus, similar in size and "geological" characteristics to our planet – that is, like Earth, it is a rocky planet. However, unlike Earth, Venus is probably one of the most inhospitable places in the Solar System: the temperature on the ground is about 500°C, higher than that recorded on Mercury, the planet closest to the Sun, so the Sun is not directly responsible for that infernal climate. The blame lies with the very extreme greenhouse effect on Venus. We know that the greenhouse effect is due to the presence of gases that trap solar radiation and heat the atmosphere. The main greenhouse gases are carbon dioxide (CO2), methane, water vapour and nitrogen oxides. On Earth we are rightly concerned because the amount of carbon dioxide is increasing due to human activities and with the increase in CO2, temperatures are rising. -
Search for Rings and Satellites Around the Exoplanet Corot-9B Using Spitzer Photometry A
Search for rings and satellites around the exoplanet CoRoT-9b using Spitzer photometry A. Lecavelier Etangs, G. Hebrard, S. Blandin, J. Cassier, H. J. Deeg, A. S. Bonomo, F. Bouchy, J. -m. Desert, D. Ehrenreich, M. Deleuil, et al. To cite this version: A. Lecavelier Etangs, G. Hebrard, S. Blandin, J. Cassier, H. J. Deeg, et al.. Search for rings and satellites around the exoplanet CoRoT-9b using Spitzer photometry. Astronomy and Astrophysics - A&A, EDP Sciences, 2017, 603, pp.A115. 10.1051/0004-6361/201730554. hal-01678524 HAL Id: hal-01678524 https://hal.archives-ouvertes.fr/hal-01678524 Submitted on 16 Jan 2021 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. A&A 603, A115 (2017) Astronomy DOI: 10.1051/0004-6361/201730554 & c ESO 2017 Astrophysics Search for rings and satellites around the exoplanet CoRoT-9b using Spitzer photometry A. Lecavelier des Etangs1, G. Hébrard1; 2, S. Blandin1, J. Cassier1, H. J. Deeg3; 4, A. S. Bonomo5, F. Bouchy6, J.-M. Désert7, D. Ehrenreich6, M. Deleuil8, R. F. Díaz9; 10, C. Moutou11, and A. Vidal-Madjar1 1 Institut d’astrophysique de Paris, CNRS, UMR 7095 & Sorbonne Universités, UPMC Paris 6, 98bis Bd Arago, 75014 Paris, France e-mail: [email protected] 2 Observatoire de Haute-Provence, CNRS/OAMP, 04870 Saint-Michel-l’Observatoire, France 3 Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain 4 Universidad de La Laguna, Dept. -
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. -
Lockheed Martin to Help NASA Uncover Mysteries of Venus with VERITAS and DAVINCI+ Spacecraft
Lockheed Martin to Help NASA Uncover Mysteries of Venus with VERITAS and DAVINCI+ Spacecraft June 2, 2021 Lockheed Martin has a major role in NASA's long-anticipated return to Venus DENVER, June 2, 2021 /PRNewswire/ -- To learn more about how terrestrial planets evolve over time, NASA selected the VERITAS and DAVINCI+ missions for its Discovery Program, both bound for Venus. Lockheed Martin will design, build and operate both spacecraft. The missions will launch in 2026 and 2030 respectively, and will combine to study Venus' dense atmosphere, topography and geologic processes in great depth. Both missions will aim to discover how Venus – which may have been the first potentially habitable planet in our solar system – became inhospitable to life. They represent NASA's return to Earth's sister planet after more than three decades. "We're very grateful for this opportunity to work with NASA and the missions' principal investigators to fully understand how rocky planets evolved and what it means for our planet, Earth," said Lisa Callahan, vice president and general manager of Lockheed Martin's Commercial Civil Space business. "Our team who designed these two spacecraft to study Venus in unprecedented detail – and yield answers to its greatest mysteries – is beyond excited!" The operations and science for DAVINCI+ – which stands for Deep Atmosphere Venus Investigation of Noble Gases, Chemistry and Imaging Plus – will be managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland. VERITAS – which stands for Venus Emissivity, Radio Science, InSAR, Topography & Spectroscopy – will have its science and operations managed by NASA's Jet Propulsion Laboratory in Southern California. -
Hints of Life on Venus John I Davies
News Feature: Hints of life on Venus John I Davies On the 14th of September 2020, the world was briefly distracted from its many present troubles by an announcement from the Royal Astronomical Society, Hints of life on Venus (ras.ac.uk/news-and- press/news/hints-life-venus). Subsequent analysis has questioned the discovery of the spectroscopic signature of molecule Phospine, chemical formula PH3 (en.wikipedia.org/wiki/Phosphine). The problem remains unresolved and in situ examination might be the best way of solving the Synthesized false colour image of Venus, using 283-nm mystery. and 365-nm band images taken by the Venus Ultraviolet Imager (UVI). JAXA / ISAS / Akatsuki Project Team Here John Davies summarises the research and the Source: CBS News response by i4is and others. See also www.cbsnews.com/video/venus-potential-life- discovered-on-planet Discovery Two major classes of chemical process are known to produce phosphine elsewhere in the Solar system. One is the highly energetic convective storms found in the atmospheres of gas giants such as Jupiter and the other is from living processes on Earth. So have we found a biosignature on Venus? The paper in Nature Astronomy is - Greaves, JS, Richards, AMS, Bains, W et al. Phosphine gas in the cloud decks of Venus. Nature Astronomy (2020). doi.org/10.1038/s41550-020-1174-4. (Received 07 February 2020). The paper is available at - www.nature.com/articles/s41550-020-1174-4.pdf. The lead author is Jane S Greaves, of the universities of Cardiff and Cambridge, UK. Other authors are from Jodrell Bank, MIT, Cambridge University, Kyoto Sangyo University, Imperial College London, Cardiff University, The UK Open University and East Asian Observatory Hawaii. -
Constraints on a Potential Aerial Biosphere on Venus: I. Cosmic Rays ⇑ Lewis R
Icarus 257 (2015) 396–405 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Constraints on a potential aerial biosphere on Venus: I. Cosmic rays ⇑ Lewis R. Dartnell a, , Tom Andre Nordheim b,c, Manish R. Patel d,e, Jonathon P. Mason d, Andrew J. Coates b,c, Geraint H. Jones b,c a Space Research Centre, Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK b Mullard Space Science Laboratory, University College London, Dorking, Surrey RH5 6NT, UK c Centre for Planetary Sciences at UCL/Birkbeck, University College London, Gower Street, London WC1E 6BT, UK d Department of Physical Sciences, The Open University, Milton Keynes, UK e Space Science and Technology Department, STFC Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, UK article info abstract Article history: While the present-day surface of Venus is certainly incompatible with terrestrial biology, the planet may Received 31 October 2014 have possessed oceans in the past and provided conditions suitable for the origin of life. Venusian life Revised 10 April 2015 may persist today high in the atmosphere where the temperature and pH regime is tolerable to terrestrial Accepted 7 May 2015 extremophile microbes: an aerial habitable zone. Here we argue that on the basis of the combined Available online 15 May 2015 biological hazard of high temperature and high acidity this habitable zone lies between 51 km (65 °C) and 62 km (À20 °C) altitude. Compared to Earth, this potential venusian biosphere may be exposed to Keywords: substantially more comic ionising radiation: Venus has no protective magnetic field, orbits closer to Astrobiology the Sun, and the entire habitable region lies high in the atmosphere – if this narrow band is sterilised Cosmic rays Exobiology there is no reservoir of deeper life that can recolonise afterwards.