DOCSLIB.ORG

Sigam a Água -1 FOLLOW the LIFE  • Solvent • Biogenic Elements • Source of Free Energy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Sigam a Água -1 FOLLOW the LIFE  • Solvent • Biogenic Elements • Source of Free Energy Sigam a Água -1 FOLLOW THE LIFE • Solvent • Biogenic elements • Source of Free Energy searches for life within our solar system commonly retreat from a search for life to a search for “life as we know it,” meaning life based on liquid water, a suite of so-called “biogenic” elements (most famously carbon), and a usable source of free energy. (Chyba & Hand, 2005, p. 34) FOLLOW THE LIFE • Follow the water • Follow the carbon • Follow the nitrogen • Follow the energy • Follow the entropy • Follow the information Zona Habitável Estelar Distância certa da estrela água líquida R A História dos Cachinhos Dourados Nem quente demais, senão ferve Nem frio demais, senão congela No Sistema Solar: Vênus sempre foi quente demais Marte, no passado, já esteve no ponto. A Terra em geral esteve no ponto, exceto em duas ocasiões de quase total congelamento Primeiro exoplaneta descoberto na Zona Habitável (2007) Gliese 581c Astrônomos descobrem planeta que pode ser habitável Folha Online 24/04/2007 - 22h44 Astrônomos encontraram um planeta fora do nosso Sistema Solar que é po- tencialmente habitável, com temperaturas parecidas com as da Terra. A des- coberta foi considerada um grande passo na procura por vida extraterrestre. O planeta tem o tamanho certo, pode ter água em forma líquida e, em termos de Universo, está relativamente perto, a cerca de 20,5 anos-luz da Terra. Ele gira em torno de uma anã vermelha --uma estrela muito menor, menos luminosa e mais fria que o nosso Sol-- chamada de Gliese 581. O planeta, batizado de Gliese 581c, foi descoberto pelo telescópio do Observatório Sistema planetário de Gliese 581 Europeu do Sul (ESO) em La Silla, no Chile. O novo planeta é cinco vezes mais pesado que a Terra. Não se sabe ainda se ele é rochoso como a Terra ou se é uma esfera de gelo, com água líquida na superfície. Se for rochoso, que é o que a teoria prevalecente propõe, tem um diâmetro cerca de 1,5 vez maior que o do nosso planeta. Se for uma esfera de gelo, seria maior ainda. Instrumentos utilizados da descoberta de Gliese 581c Telescópio de 3,6m do ESO, em La Silla, Chile, a 2400m de altitude Equipe descobridora de Gliese 581c Uma equipe de onze astrônomos da Suíça, França, e Portugal. Esta equipe faz parte do grupo liderado por Michel Mayor, do Observatório de Genebra, Michel Mayor na Suíça, responsável pela descoberta de 89 exoplanetas (até 4/6/2007) Há 242 exoplanetas descobertos até essa data O Estranho Sistema Solar de Gliese 581 Planeta Massa “Ano” Distância Gliese 581b 15 MTerra 5,4 dias 6 milhões km Gliese 581c 5 MTerra 13 dias 11 milhões km Distância “certa” para água líquida (temperatura= 0-40 C) Gliese 581d 15 MTerra 84 dias 38 milhões km Gliese 581c – um mundo aquático? Um planeta de classe Aurélia? Um lado, dia para sempre Outro lado, noite eterna A Terra é o “Planeta Água”? Há mais água no manto terrestre do que nos oceanos Água Composta pelos dois elementos quimicamente ativos mais abundantes do Universo. Principal componente dos cometas e dos seres vivos. Assim, o Oxigênio e o Hidrogênio são os elementos principais de seres vivos terrestres e do Universo Logo atrás vem o Carbono e o Nitrogênio. DNA C H O N + P Six “Major Biogenic Elements”: Carbon, Hydrogen, Oxygen, Nytrogen, Phosphorous, Sulfur (CHON + P + S) Five “Minor Biogenic Elements”: Sodium, Potassium, Magnesium, Calcium, Chlorine Relative abundances of chemical elements Relative abundances of chemical elements (O=100) The abundances are in number (decreasing order) Sources: Lehninger 2000 (human body and Earth crust abundances); Asplind, Grevesse & Sauval 2004 (C, N, and O are solar photospheric values; the other elements are solar system meteoritic values) Human Body Earth Crust Cosmic H 247 O 100 H 21 900 O 100 Si 59.6 O 100 C 37.3 Al 16.8 C 53.7 N 5.49 Fe 9.6 N 13.2 Ca 1.22 Ca 7.5 Mg 7.41 P 0.86 Na 5.3 Si 7.10 Cl 0.31 K 5.3 Fe 6.17 K 0.24 Mg 4.7 S 3.16 S 0.20 Ti 1.1 Al 0.58 Na 0.12 H 0.4 Ca 0.43 Mg 0.04 C 0.4 Na 0.41 A água é essencial para a vida como conhecemos H2O A água também pode ser essencial para a vida em outros pontos do Universo Afinal, há água por toda parte no Universo H2O = Hidrogênio + Oxigênio Hidrogênio é o elemento mais abundante do Universo e o mais simples (só um próton) Oxigênio (seis prótons e seis nêutrons) é o segundo elemento quimicamente ativo mais abundante Hélio (dois prótons e dois nêutrons) é o segundo elemento mais abundante mas não é quimicamente ativo O UNIVERSO É ÚMIDO Detecting Water through the PAH 6.2 line Spitzer Diâmetro: 0,85 m Water Ice Line PANH z=1.83 Phase Diagram for Water Critical Point 647 K, 22.064 MPa Triple Point 273.16 K, 611.73 Pa Liquid Water • H20 is the combination of the two most abundant chemical elements in the Universe • H20 is the most abundant tri-atomic molecule in the Universe (requires stars) • liquid H20 is much less common (a narrow range of pressure and temperatures) • liquid H20 requires planetary environments • highest boiling temp= 650 K (high pressures) History of the Complexity in the Universe • 10-43 s 1. The space is born (4 extended dimensions) • 10-33 s 2. The matter is born (quarks & leptons) • 10-4 s 3. Baryons are born (quark confinements) • 1 minute 4. Nuclei are born (4He 2H 3He 7Li) • 300.000 yr 5. Atoms are born (H recombination) • 300 Myr 6. Heavy elements are born (C, O…) • 7. Heteromolecules are born (OH, CO, H2O…) • ~10 Gyr 8. Life is born (: at least 3.5 Gyr ago) Thermal History of the Universe Transitions in the universe as the temperature decreases. Structures which freeze out as the universe cools include, matter, protons and neutrons, nuclei, atoms and molecules. Transitions in the late Universe. The thin line beneath the CMB line shows how hydrogen cooled more rapidly than the CMB. The dashed line shows how this cooling would have continued if it had not been for the fact that a billion years after the big bang, the thermal energy of the hydrogen sank low enough to allow the weak gravitational binding energy to contract the densest clouds of hydrogen. These clouds then became denser and hotter and eventually formed the first stars in the universe. These massive stars emitted UV photons that heated and ionized the more rarified hydrogen (intergalactic medium : IGM). The formation of these first massive stars and the re-ionization of the IGM are represented by the vertical line at 109 years. The other lines originating at the same point represent the temperatures of hydrogen clouds that were dense enough to self-shield and avoid UV ionization. These clouds were gradually enriched with oxygen, carbon, nitrogen, iron and the other waste products of the supernovae explosions of thefirst, massive, short-lived stars. About 4.6 billion years ago one of these enriched clouds was shocked by a nearby supernova. This initiated collapse and star formation. One of the stars was the Sun. Planetary formation and formation of the Earth was part of this collapse (dotted line). Other, less dense clouds of H2 (represented by the three other thin lines) collapsed a bit but stayed at 10 or 20 K. The upper x axis shows that free energy is available once the temperature of the hydrogen is low enough to initiate gravitational collapse and star formation. Two adjacent grey strips are labeled “water”. The lower darker one is 0-100 C. The higher lighter one is 100-650 C; the highest temperatures at which water, under pressure, can exist. Hot Ancestors and their Cool Descendants: Maximum Growth Temperatures Phylogenetic tree of life based on 16S rRNA sequences (Pace 1997). Maximal growth temperatures have been used to color-code the branches Re-setting the Phylogenetic Thermometer O SISTEMA SOLAR É ÚMIDO SOL MARTE Água em Marte hoje •A baixa pressão atmosférica impede água liquída na superfície Água líquida em Marte hoje? • Ponto Triplo da água: (T,p)=(271.16 K, 611.73 Pa) • Pressão média em Marte: T= 600 Pa • Pressão míxima: 30 Pa (Olympus Mons) • Pressão máxima: 1150 Pa (Hellas Planitia) Water on Mars Water on Mars Water on Mars Water droplets collected on NASA’s Phoenix lander Cratera Garni Descoberta água líquida em Marte! (28/9/2015) Europa Extremófilos Antarctica • Temperatura: -15° C < T < 230° C • 0.06 < pH < 12.8 • 0 < Pressão < 1200 atm • Seu metabolismo pode dispensar o oxigênio Hidrotermal • 20-40 milhões de anos de dormência vents • 2 ½ anos no espaço, a –250 C, sem nutrientes, água and expostos a radiação (Strep. Mitis) Criptoendoliths Hot geisers and volcans Thermophile bacteria Kuhn Enceladus PLUTÃO New Horizons CLOSEST APROXIMATION 12.500 km 2015/07/15 00:52 GMT Major Comet Structures HI CLOUD ION TAIL NUCLEUS COMA THE COMA Molecules are liberated from the nucleus by solar heating and sublimation Molecules are destroyed by photodissociation & photoionization H2O + h H + OH OH + h H + O + - H2O + h H2O + e Nucleus molecules are referred to as the “parent molecules” The fragments produced by the absorption of a photon are called “daughters” Origem Cometária da Água na Terra? Super Terras e Planetas-Oceano ALTERNATIVE CHEMISTRIES FOR LIFE? Evidence for chemical diversity Diversity among Oort cloud comets No systematic differences between Oort cloud and « Kuiper belt » comets Crovisier 2005 Phase transition properties of possible biosolvents Substance Melting Boiling Temperature range Triple point Triple point Point (K) point (K) for liquid (K)* temperature (K) pressure (Pa) Water (H2O) 273.15 373.15 100 237.16 611.73 Carbon monoxide (CO) 68 81.64 13 68.13 15400 Carbon dioxide (CO2) - - - 216.58 518500 Ammonia (NH3) 195.42 239.81 44 195.40 6076 Methane (CH4) 91.
Load more

Recommended publications
  • Naming the Extrasolar Planets
    Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named.
    [Show full text]
  • Arxiv:0809.1275V2
    How eccentric orbital solutions can hide planetary systems in 2:1 resonant orbits Guillem Anglada-Escud´e1, Mercedes L´opez-Morales1,2, John E. Chambers1 [email protected], [email protected], [email protected] ABSTRACT The Doppler technique measures the reflex radial motion of a star induced by the presence of companions and is the most successful method to detect ex- oplanets. If several planets are present, their signals will appear combined in the radial motion of the star, leading to potential misinterpretations of the data. Specifically, two planets in 2:1 resonant orbits can mimic the signal of a sin- gle planet in an eccentric orbit. We quantify the implications of this statistical degeneracy for a representative sample of the reported single exoplanets with available datasets, finding that 1) around 35% percent of the published eccentric one-planet solutions are statistically indistinguishible from planetary systems in 2:1 orbital resonance, 2) another 40% cannot be statistically distinguished from a circular orbital solution and 3) planets with masses comparable to Earth could be hidden in known orbital solutions of eccentric super-Earths and Neptune mass planets. Subject headings: Exoplanets – Orbital dynamics – Planet detection – Doppler method arXiv:0809.1275v2 [astro-ph] 25 Nov 2009 Introduction Most of the +300 exoplanets found to date have been discovered using the Doppler tech- nique, which measures the reflex motion of the host star induced by the planets (Mayor & Queloz 1995; Marcy & Butler 1996). The diverse characteristics of these exoplanets are somewhat surprising. Many of them are similar in mass to Jupiter, but orbit much closer to their 1Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Rd.
    [Show full text]
  • Annual Report 2007 ESO
    ESO European Organisation for Astronomical Research in the Southern Hemisphere Annual Report 2007 ESO European Organisation for Astronomical Research in the Southern Hemisphere Annual Report 2007 presented to the Council by the Director General Prof. Tim de Zeeuw ESO is the pre-eminent intergovernmental science and technology organisation in the field of ground-based astronomy. It is supported by 13 countries: Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Further coun- tries have expressed interest in member- ship. Created in 1962, ESO provides state-of- the-art research facilities to European as- tronomers. In pursuit of this task, ESO’s activities cover a wide spectrum including the design and construction of world- class ground-based observational facili- ties for the member-state scientists, large telescope projects, design of inno- vative scientific instruments, developing new and advanced technologies, further- La Silla. ing European cooperation and carrying out European educational programmes. One of the most exciting features of the In 2007, about 1900 proposals were VLT is the possibility to use it as a giant made for the use of ESO telescopes and ESO operates the La Silla Paranal Ob- optical interferometer (VLT Interferometer more than 700 peer-reviewed papers servatory at several sites in the Atacama or VLTI). This is done by combining the based on data from ESO telescopes were Desert region of Chile. The first site is light from several of the telescopes, al- published. La Silla, a 2 400 m high mountain 600 km lowing astronomers to observe up to north of Santiago de Chile.
    [Show full text]
  • Andrea Gróf Zsuzsa Horváth Exercises in Astronomy and Space
    Andrea Gróf Zsuzsa Horváth Exercises in astronomy and space exploration for high school students ELTE DOCTORAL SCHOOL OF PHYSICS ANDREA GRÓF, ZSUZSA HORVÁTH EXOPLANETS AND SPACECRAFT Exercises in astronomy and space exploration for high school students ELTE DOCTORAL SCHOOL OF PHYSICS BUDAPEST 2021 The publication was supported by the Subject Pedagogical Research Programme of the Hungarian Academy of Sciences Reviewers: József Kovács (astronomy), Ákos Szeidemann (didactics) Translation from Hungarian: Attila Salamon © Andrea Gróf, Zsuzsa Horváth ELTE Doctoral School of Physics Responsibe publisher: Dr. Jenő Gubicza Budapest 2021 2 Second, revised edition Compiled by: Andrea Gróf, Zsuzsa Horváth Professional proof-reader: Dr. József Kovács, ELTE Gothard Astrophysical Observatory The creation of the exercise book was supported by the Subject Pedagogical Research Program of the Hungarian Academy of Sciences. Table of contents Introduction ..................................................................................................................... 3 Acknowledgements .......................................................................................................... 4 1. Introduction of exoplanets .......................................................................................... 5 DIMENSIONS AND DISTANCES ..................................................................................................... 5 THE HABITABLE ZONE OF EXOPLANETS, ................................................................................
    [Show full text]
  • UM ESTUDO SOBRE O Momentum ANGULAR
    UNIVERSIDADE FEDERAL DO RIO GRANDE DO NORTE CENTRO DE CIÊNCIAS EXATAS E DA TERRA DEPARTAMENTO DE FÍSICA TEÓRICA E EXPERIMENTAL JULIANA CERQUEIRA DE SANTANA UM ESTUDO SOBRE O Momentum ANGULAR TOTAL DE ESTRELAS COM PLANETAS DISSERTAÇÃO DE MESTRADO NATAL, RN NOVEMBRO DE 2011 JULIANA CERQUEIRA DE SANTANA UM ESTUDO SOBRE O Momentum ANGULAR TOTAL DE ESTRELAS COM PLANETAS Trabalho apresentado ao Programa de Pós- graduação em Física do Departamento de Física Teórica e Experimental da UNIVER- SIDADE FEDERAL DO RIO GRANDE DO NORTE como requisito parcial para obtenção do grau de Mestre em Física. Orientador: Prof. Dr. José Renan de Medeiros NATAL, RN NOVEMBRO DE 2011 Aos meus queridos pais Nilza e Roque, a quem eu tanto amo e que me inspiram a cada dia que acordo. ii Agradecimentos Assim como em nossa formação enquanto sujeito fomos orientados a agradecer por algum feito realizado em prol de nosso bem estar, nesse momento não é diferente. Agradeço a Deus, fonte de força espiritual, onde sempre busquei carregar minhas energias e toda esperança, pois o indivíduo não é feito só de razão. Agradeço aos meus pais Nilza e Roque, pelo seu amor in- condicional e por sua compreensão em todas minhas ausências. Ao professor José Renan pelos conhecimentos transmitidos e mais ainda que isso, pelos ensinamentos que ultrapassam as fron- teiras da Universidade. A sua figura de grande cientista que desperta o respeito e admiração de muitos. Aos meus irmãos Cida, Sérgio e André, que sempre me apoiaram em minhas esco- lhas. Agradeço ao professor Marildo pelo incentivo em todo momento da minha graduação, principalmente nos períodos iniciais deste curso.
    [Show full text]
  • Global Climate Models Applied to Terrestrial Exoplanets
    GLOBAL CLIMATE MODELS APPLIED TO TERRESTRIAL EXOPLANETS F.Forget, R. Wordsworth B. Charnay, E. Millour, S. Lebonnois, Laboratoire de Météorologie Dynamique, Université Paris 6, BP 99, 75005 Paris, FRANCE GLOBAL CLIMATE MODELS APPLIED TO TERRESTRIAL EXOPLANETS F.Forget, R. Wordsworth B. Charnay, E. Millour, S. Lebonnois, Laboratoire de Météorologie Dynamique, Université Paris 6, BP 99, 75005 Paris, FRANCE General Circulation Models/ GCMs Global Climate models ⇒ 3D Numerical simulators of a planetary environment: designed to simulate the « entire reality » MARS VENUS TERRE TITAN Several GCMs ~a few GCMs ~2 true GCMs (NASA Ames, (LMD, Univ. Od Coupling dynamic & Caltech, GFDL, LMD, Chicago, Caltech, radiative transfer AOPP, MPS, Japan, Köln…) York U., Japan, etc…) (LMD, Kyushu/Tokyo Coupled cycles: university) Applications: • Aerosols • Dynamics & • Photochemistry assimilation • Clouds • CO2 cycle • dust cycle • water cycle • Photochemistry • thermosphere and ionosphere TRITON • isotopes cycles 1 GCM (LMD) • paleoclimates • etc… • An ambitious goal : Building virtual planets behaving like the real ones, on the basis of universal equations Observations Reality Models How GCM work ? : The minimum General CirculationMost processes can Model for a terrestrial planet be described by equations that we have learned to solve 1) 3D Hydrodynamical code with some accuracy ⇒ to compute large scale atmospheric motions and transport 2) At every grid point : Physical parameterizations ⇒ to force the dynamic ⇒ to compute the details of the local climate
    [Show full text]
  • Efemeriszek Pontosítása Fedési Bolygórendszerekben
    Eötvös Loránd Tudományegyetem Természettudományi Kar Csillagászati Tanszék Szakdolgozat Efemeriszek pontosítása fedési bolygórendszerekben Szerz®: Bakai Zoárd Témavezet®: Pál András Bels® konzulens: Érdi Bálint 2010 ENSIS D TIN E S E E Ö P T A V D Ö U S B . *F *. A T C A U . N LTAS SCI Tartalomjegyzék 1. Bevezetés 1 1.1. A kezdeti exobolygókutatás rövid története . 1 1.2. Közvetlen bolygó meggyelési módszerek . 2 1.3. Közvetett bolygó meggyelési módszerek . 2 1.4. Óriásbolygó vagy barna törpe? . 6 1.5. Fedési exobolygók jelent®sége . 7 1.6. Az els® neptunusztömeg¶ fedési exobolygó . 8 1.7. Szuper-Földek kutatása . 8 1.8. Exoholdak kutatása . 10 1.9. Exobolygókutatás fejl®dése, ¶rtávcsövek . 11 1.10. A jöv®ben tervezett ¶rprogramok . 13 1.11. Célkit¶zés . 15 2. A vizsgált fedési exobolygók 17 2.1. A TrES program . 17 2.2. Az XO program . 17 2.3. A HATNet program . 18 2.4. A vizsgált exobolygók . 18 3. Fotometriai meggyeléseink 27 3.1. A meggyelések . 27 3.2. Adatok feldolgozása . 28 4. Fénygörbe meghatározása 31 4.1. Szabad paraméterek meghatározása . 31 4.2. Szabad paraméterek illesztése . 34 4.3. Fénygörbe illesztése . 37 5. Összefoglalás 44 6. Kivonat 50 Köszönetnyilvánítás 51 Hivatkozások 52 1. Bevezetés Mint ismert Naprendszerünk egy csillagból és a körülötte Kepler-pályán közelít®leg egy síkban kering® nyolc bolygóból áll, így alkotva egy bolygórend- szert. Az Univerzumban ez a fajta rendszer mégsem a leggyakoribb, sokkal inkább jellemz®ek a kett®scsillagok, illetve a többes számú csillagrendsze- rek. A modern csillagászat megszületését®l szinte mindenki egyetértett azzal a hipotézissel, hogy Naprendszeren kívül is léteznek bolygók, de kutatásuk lehet®sége fel sem merült egészen a 19.
    [Show full text]
  • Ralf Schoofs.Pdf
    BILDAUSWAHL DER KÜNSTLER / FOTOGRAFEN BEI ASTROFOTO --- www.astrofoto.de --- Repräsentative Auswahl der erfolgreichsten Bilder (Farben unverbindlich). Die hier präsentierten Bilder dürfen nur für interne Layoutzwecke verwendet werden. Mit dem Downlaod ist keine Übertragung von Nutzungsrechten verbunden, diese müssen vor einer möglichen Nutzung eingeholt werden. Feindaten per Download / e-Mail / Leonardo Bildnummer: er001-100 Bildnummer: er001-107 Nachtseite der Erde, Erde bei Nacht, Erdkugel, Polarlichtoval Nachtseite der Erde, Polarlichtoval, Sonne, Sterne, Sternenhimmel (Illustration) (Illustration) © Ralf Schoofs © Astrofoto/Ralf Schoofs © Astrofoto/Ralf Schoofs Bildnummer: er001-108 Bildnummer: er001-109 Erdkugel (Satellitenfoto) vor Sternenhimmel (Illustration) Erdkugel, Erde, Nordamerika, Südamerika, Atlantik, Europa, Asien, © Astrofoto/Ralf Schoofs Nordpol (Satellitenfoto) vor Sternenhimmel (Illustration) © Ralf Schoofs © Astrofoto/Ralf Schoofs Copyright: © Astrofoto Astrofoto Inh. Bernd Koch e.K. Ihr persönlicher Ansprechpartner: Bernd Koch Hauptstr. 3A, D-57636 Sörth Kontakt: [email protected] Telefon +49-2681-983580 Fax: 983582 BILDAUSWAHL DER KÜNSTLER / FOTOGRAFEN BEI ASTROFOTO --- www.astrofoto.de --- Repräsentative Auswahl der erfolgreichsten Bilder (Farben unverbindlich). Die hier präsentierten Bilder dürfen nur für interne Layoutzwecke verwendet werden. Mit dem Downlaod ist keine Übertragung von Nutzungsrechten verbunden, diese müssen vor einer möglichen Nutzung eingeholt werden. Feindaten per Download / e-Mail /
    [Show full text]
  • Tidal Locking
    Tidal locking Tidal locking (also called gravitational locking or captured rotation) occurs when the long-term interaction between a pair of co-orbiting astronomical bodies drives the rotation rate of at least one of them into the state where there is no more net transfer of angular momentum between this body (e.g. a planet) and its orbit around the second body (e.g. a star); this condition of "no net transfer" must be satisfied over the course of one orbit around the second body.[1][2] This does not mean that the rotation and spin rates are always perfectly synchronized throughout an orbit, as there can be some Tidal locking results in the Moon rotating about its axis in about the same time it takes to orbitEarth . back and forth transfer over the course of an orbit. This effect arises Except for libration effects, this results in the Moon from the gravitational gradient (tidal force) between the co-orbiting keeping the same face turned toward Earth, as bodies, acting over a sufficiently long period of time. seen in the left figure. (The Moon is shown in polar view, and is not drawn to scale.) If the Moonwere In the special case where the orbital eccentricity and obliquity are not rotating at all, it would alternately show its near nearly zero, tidal locking results in one hemisphere of the revolving and far sides to Earth, while moving around Earth object constantly facing its partner, an effect known as synchronous in orbit, as shown in the right figure. rotation.[1][2][3] For example, the same side of the Moon always faces the Earth, although there is some libration because the Moon's orbit is not perfectly circular.
    [Show full text]
  • Gliese 581D: a Possibly Habitable Planet Around a Red Dwarf Star
    EPSC Abstracts Vol. 5, EPSC2010-417, 2010 European Planetary Science Congress 2010 c Author(s) 2010 Gliese 581d: A Possibly Habitable Planet around a Red Dwarf Star D. Schulze-Makuch (1), E.F. Guinan (2) (1) Washington State University, Pullman, WA, USA ([email protected]) (2) Villanova University, Villanova, PA, USA ([email protected]) Abstract experienced on a planetary surface, beneficial for evolutionary innovations. Moreover, because of their Gliese 581d is a terrestrial super-earth planet, located low temperatures (~2200 – 3800 K), dM stars (unlike on the inside edge of the habitable zone away from hotter stars like our Sun at T ~5779 K) do not have its parent star. If Mars would be that size in our Solar significant photospheric Near UV (NUV) continuum System, Mars would likely be a habitable planet in a radiation below about 3000A. A more serious traditional sense (stability of liquid water on its concern is that many dM star HZ planets are likely to surface). The same is likely true for Gliese 581d, be tidally locked (with Prot = Porb), probably do not which makes it a promising candidate of the possess large moons, and many may be too old to be extrasolar planets detected so far to support life. enriched enough in metals to form a terrestrial type Planets around red dwarf stars (dM) appear in planet. Nevertheless, planets around older, less principle at least as suitable for the development of magnetically-active dM stars should be considered a life as planets around dG stars. prime target for possible life, and may also serve as a refuge for advanced, intelligent civilizations when 1.
    [Show full text]
  • Appendix 1 the Eight Planets of the Solar System
    Appendix 1 The eight planets of the solar system Name Semimajor Period of Eccentricity Equatorial Mass axis revolution ie) diameter (MEarth) (AU) (years) (DEarth) Terrestrial planets Mercury 0.387 0.241 0.206 0.382 0.055 Venus 0.723 0.615 0.007 0.949 0.815 Earth 1.000 1.000 0.017 1.000 1.000 Mars 1.524 1.881 0.093 0.532 0.107 Giant planets Jupiter 5.203 11.856 0.048 11.21 317.9 Saturn 9.537 29.424 0.054 9.45 95.16 Uranus 19.191 83.747 0.047 4.00 14.53 Neptune 30.069 163.273 0.009 3.88 17.14 Appendix 2 The first 200 extrasolar planets Name Mass Period Semimajor axis Eccentricity (Mj) (years) (AU) (e) 14 Her b 4.74 1,796.4 2.8 0.338 16 Cyg B b 1.69 798.938 1.67 0.67 2M1207 b 5 46 47 Uma b 2.54 1,089 2.09 0.061 47 Uma c 0.79 2,594 3.79 0 51 Pegb 0.468 4.23077 0.052 0 55 Cnc b 0.784 14.67 0.115 0.0197 55 Cnc c 0.217 43.93 0.24 0.44 55 Cnc d 3.92 4,517.4 5.257 0.327 55 Cnc e 0.045 2.81 0.038 0.174 70 Vir b 7.44 116.689 0.48 0.4 AB Pic b 13.5 275 BD-10 3166 b 0.48 3.488 0.046 0.07 8 Eridani b 0.86 2,502.1 3.3 0.608 y Cephei b 1.59 902.26 2.03 0.2 GJ 3021 b 3.32 133.82 0.49 0.505 GJ 436 b 0.067 2.644963 0.0278 0.207 Gl 581 b 0.056 5.366 0.041 0 G186b 4.01 15.766 0.11 0.046 Gliese 876 b 1.935 60.94 0.20783 0.0249 Gliese 876 c 0.56 30.1 0.13 0.27 Gliese 876 d 0.023 1.93776 0.0208067 0 GQ Lup b 21.5 103 HD 101930 b 0.3 70.46 0.302 0.11 HD 102117 b 0.14 20.67 0.149 0.06 HD 102195 b 0.488 4.11434 0.049 0.06 HD 104985 b 6.3 198.2 0.78 0.03 1 70 The first 200 extrasolar planets Name Mass Period Semimajor axis Eccentricity (Mj) (years) (AU) (e) HD 106252
    [Show full text]
  • Arxiv:1604.04544V2 [Astro-Ph.EP] 20 Jul 2017 Ihn00 U Lo Aybnr Trsystems Mul- Star Host Star to Known the Binary Are Which Many Discovered Orbit Been Also, Have E, AU
    Dynamics of a Probable Earth-mass Planet in GJ 832 System S. Satyal1∗, J. Griffith1, Z. E. Musielak1,2 1The Department of Physics, University of Texas at Arlington, Arlington, TX 76019. 2Kiepenheuer-Institut f¨ur Sonnenphysik, Sch¨oneckstr. 6, 79104 Freiburg, Germany. ABSTRACT Stability of planetary orbits around the GJ 832 star system, which contains inner (GJ 832c) and outer (GJ 832b) planets, is investigated numerically and a detailed phase-space analysis is performed. A special emphasis is given to the existence of stable orbits for a planet less than 15M⊕ which is injected between the inner and outer planets. Thus, numerical simulations are performed for three and four bodies in elliptical orbits (or circular for special cases) by using a large number of initial conditions that cover the selected phase-spaces of the planet’s orbital parameters. The results presented in the phase-space maps for GJ 832c indicate the least deviation of eccentricity from its nominal value, which is then used to determine its inclination regime relative to the star-outer planet plane. Also, the injected planet displays stable orbital configurations for at least one billion years. Then, the radial velocity curves based on the signature from the Keplerian motion are generated for the injected planets with masses 1M⊕ to 15M⊕ in order to estimate their semimajor axes and mass-limit. The synthetic RV signal suggests that an additional planet of mass ≤ 15M⊕ with dynamically stable configuration may be residing between 0.25 - 2.0 AU from the star. We have provided an estimated number of RV observations for the additional planet that is required for further observational verification.
    [Show full text]