Dynamical Models of Terrestrial Planet Formation
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Using Kepler Systems to Constrain the Frequency and Severity of Dynamical Effects on Habitable Planets Alexander James Mustill Melvyn B
Using Kepler systems to constrain the frequency and severity of dynamical effects on habitable planets Alexander James Mustill Melvyn B. Davies Anders Johansen Dynamical instability bad for habitability • Excitation of eccentricity can shift HZ or cause extreme seasons (Spiegel+10, Dressing+10) • Planets may be scattered out of HZ • Planet-planet collisions may remove biospheres, atmospheres, water • Earth-like planets may be eaten by Neptunes/Jupiters Strong dynamical effects: scattering and Kozai • Scattering: closely-spaced giant planets excite each others’ eccentricities (Chatterjee+08) • Kozai: inclined external perturber (e.g. binary) can cause very large eccentricity fluctuations (Kozai 62, Lidov 62, Naoz 16) Relevance of inner systems to HZ • If you can • form a hot Jupiter through high-eccentricity migration • damage a Kepler system at few tenths of an au • you will damage the habitable zone too Relevance of inner systems intrinsically • Large number of single-candidate systems found by Kepler relative to multiples • Is this left over from formation? Or do the multiples evolve into singles through dynamics? (Johansen+12) • Informs models of planet formation • all the Kepler systems are interestingly different to the Solar system, but do we have two interestingly different channels of planet formation or only one? What do we know about the prevalence of strong dynamical effects? • So far know little about planets in HZ • What we do know: • Violent dynamical history strong contender for hot Jupiter migration • Many giants have high -
Dynamics of the Terrestrial Planets from a Large Number of N-Body Simulations ∗ Rebecca A
Earth and Planetary Science Letters 392 (2014) 28–38 Contents lists available at ScienceDirect Earth and Planetary Science Letters www.elsevier.com/locate/epsl Dynamics of the terrestrial planets from a large number of N-body simulations ∗ Rebecca A. Fischer , Fred J. Ciesla Department of the Geophysical Sciences, University of Chicago, 5734 S Ellis Ave, Chicago, IL 60637, USA article info abstract Article history: The agglomeration of planetary embryos and planetesimals was the final stage of terrestrial planet Received 6 September 2013 formation. This process is modeled using N-body accretion simulations, whose outcomes are tested by Received in revised form 26 January 2014 comparing to observed physical and chemical Solar System properties. The outcomes of these simulations Accepted 3 February 2014 are stochastic, leading to a wide range of results, which makes it difficult at times to identify the full Availableonline25February2014 range of possible outcomes for a given dynamic environment. We ran fifty high-resolution simulations Editor: T. Elliott each with Jupiter and Saturn on circular or eccentric orbits, whereas most previous studies ran an Keywords: order of magnitude fewer. This allows us to better quantify the probabilities of matching various accretion observables, including low probability events such as Mars formation, and to search for correlations N-body simulations between properties. We produce many good Earth analogues, which provide information about the mass terrestrial planets evolution and provenance of the building blocks of the Earth. Most observables are weakly correlated Mars or uncorrelated, implying that individual evolutionary stages may reflect how the system evolved even late veneer if models do not reproduce all of the Solar System’s properties at the end. -
Carnegie Institution of Washington Department of Terrestrial Magnetism Washington, DC 20015-1305
43 Carnegie Institution of Washington Department of Terrestrial Magnetism Washington, DC 20015-1305 This report covers astronomical research carried out during protostellar outflows have this much momentum out to rela- the period July 1, 1994 – June 30, 1995. Astronomical tively large distances. Planetary nebulae do not, but with studies at the Department of Terrestrial Magnetism ~DTM! their characteristic high post-shock temperatures, collapse of the Carnegie Institution of Washington encompass again occurs. Hence all three outflows appear to be able to observational and theoretical fields of solar system and trigger the collapse of molecular clouds to form stars. planet formation and evolution, stars and star formation, Foster and Boss are continuing this work and examining galaxy kinematics and evolution, and various areas where the possibility of introducing 26Al into the early solar system these fields intersect. in a heterogeneous manner. Some meteoritical inclusions ~chondrules! show no evidence for live 26Al at the time of their formation. So either the chondrules formed after the 1. PERSONNEL aluminium had decayed away, or the solar nebula was not Staff Members: Sean C. Solomon ~Director!, Conel M. O’D. Alexander, Alan P. Boss, John A. Graham, Vera C. Rubin, uniformly populated with the isotope. Foster & Boss are ex- Franc¸ois Schweizer, George W. Wetherill ploring the injection of shock wave particles into the collaps- Postdoctoral Fellows: Harold M. Butner, John E. Chambers, ing solar system. Preliminary results are that ;40% of the Prudence N. Foster, Munir Humayun, Stacy S. McGaugh, incident shock particles are swallowed by the collapsing Bryan W. Miller, Elizabeth A. Myhill, David L. -
Lecture 9—Is the Earth Rare?
41st Saas-Fee Course From Planets to Life 3-9 April 2011 Lecture 9—Is the Earth Rare? List of Rare Earth arguments/ Nitrogen abundance/ Frequency of large impacts/ Chaotic obliquity fluctuations J. F. Kasting The Gaia hypothesis First presented in the 1970s by James Lovelock 1979 1988 • Life itself is what stabilizes planetary environments • Corollary: A planet might need to be inhabited in order to remain habitable The Medea and Rare Earth hypotheses Peter Ward 2009 2000 Medea hypothesis: Life is harmful to the Earth! Rare Earth hypothesis: Complex life (animals, including humans) is rare in the universe Additional support for the Rare Earth hypothesis • Lenton and Watson think that complex life (animal life) is rare because it requires a series of unlikely evolutionary events – the origin of life – the origin of the genetic code – the development of oxygenic photosynthesis) – the origin of eukaryotes – the origin of sexuality 2011 Rare Earth/Gaia arguments 1. Plate tectonics is rare --We have dealt with this already. Plate tectonics is not necessarily rare, but it requires liquid water. Thus, a planet needs to be within the habitable zone. 2. Other planets may lack magnetic fields and may therefore have harmful radiation environments and be subject to loss of atmosphere – We have talked about this one also. Venus has retained its atmosphere. The atmosphere itself provides protection against cosmic rays 3. The animal habitable zone (AHZ) is smaller than the habitable zone (HZ) o – AHZ definition: Ts = 0-50 C o – HZ definition: Ts = 0-100 C. But this is wrong! For a 1-bar atmosphere like Earth, o water loss begins when Ts reaches 60 C. -
Chapter 9: the Origin and Evolution of the Moon and Planets
Chapter 9 THE ORIGIN AND EVOLUTION OF THE MOON AND PLANETS 9.1 In the Beginning The age of the universe, as it is perceived at present, is perhaps as old as 20 aeons so that the formation of the solar system at about 4.5 aeons is a comparatively youthful event in this stupendous extent of time [I]. Thevisible portion of the universe consists principally of about 10" galaxies, which show local marked irregularities in distribution (e.g., Virgo cluster). The expansion rate (Hubble Constant) has values currently estimated to lie between 50 and 75 km/sec/MPC [2]. The reciprocal of the constant gives ages ranging between 13 and 20 aeons but there is uncertainty due to the local perturbing effects of the Virgo cluster of galaxies on our measurement of the Hubble parameter [I]. The age of the solar system (4.56 aeons), the ages of old star clusters (>10" years) and the production rates of elements all suggest ages for the galaxy and the observable universe well in excess of 10" years (10 aeons). The origin of the presently observable universe is usually ascribed, in current cosmologies, to a "big bang," and the 3OK background radiation is often accepted as proof of the correctness of the hypothesis. Nevertheless, there are some discrepancies. The observed ratio of hydrogen to helium which should be about 0.25 in a "big-bang" scenario may be too high. The distribution of galaxies shows much clumping, which would indicate an initial chaotic state [3], and there are variations in the spectrum of the 3OK radiation which are not predicted by the theory. -
Curriculum Vitae
CURRICULUM VITAE Smadar Naoz September 2021 Contact University of California Los Angeles, Information Department of Physics & Astronomy 30 Portola Plaza, Box 951547 E-mail: [email protected] Los Angeles, CA 90095 WWW: http://www.astro.ucla.edu/∼snaoz/ Research Dynamics of planetary, stellar and black hole systems, which include formation of Hot Jupiters, Interests globular clusters, spiral structure, compact objects etc. Cosmology, structure formation in the early Universe, reionization and 21cm fluctuations. Education Tel Aviv University, Tel Aviv, Israel Ph.D. in Physics, January 2010 Hebrew University of Jerusalem, Jerusalem, Israel M.S. in Physics, Magna Cum Laude, 2004 B.S. in Physics 2002 Positions University of California, Los Angeles Associate professor since July 2019 Howard & Astrid Preston Term Chair in Astrophysics since July 2018 Assistant professor 2014-2019 Harvard Smithsonian CfA, Institute for Theory and Computation Einstein Fellow, September 2012 { June 2014 ITC Fellow, September 2011 { August 2012 Northwestern University, CIERA Gruber Fellow, September 2010 { August 2011 Postdoctoral associate in theoretical astrophysics, January 2010 { August 2010 Scholarships Helen B. Warner Prize, awarded by the American Astronomical Society, 2020 Honors and Scialog fellow, and accepted proposal, Signatures of Life in the Universe, 2020/2021 (conference Awards postponed to 2021 due to COVID-19) Career Commitment to Diversity, Equity and Inclusion Award, given by UCLA Academic Senate 2019. For other diversity awards, see xDEI. Hellman Fellows Award, awarded by Hellman Fellows Program, aimed to support the research of promising Assistant Professors who show capacity for great distinction in their research, June 2017 Multiple departmental teaching awards 2015-2019, see xTeaching, for details Sloan Research Fellowships awarded by the Alfred P. -
The Iron Planet Sex and Skin Color
PERIODICALS Yet, this is the key to the lesson, Kass says. necessary condition for national self- "God's dispersion of the nations is the PO- awareness and the possibility of a politics litical analog to the creation of woman: in- that will. hearken to the voice of what is stituting otherness and opposition, it is the eternal, true, and good." SCIENCE & TECHNOLOGY ''Mercu~'~Heart of Iron" by Clark R. Chapman, in Asfrononzy The Iron Planet (Nov. 19881, 1027 N. 7th St., Milwaukee, Wisc. 53233. More than a decade after America's un- plays a vita1 role in the two leading theo- manned Mariner 10 flew near the planet ries of the origins of the solar system. Ac- Mercury during 1974-75, scientists have fi- cording to one theory, formulated by cos- nally digested all of the data from the mochemist John Lewis during the 1970~~ flight. And they are starting to ask some the solar system was created in a more or big questions, reports Chapman, of Tuc- less orderly fashion. Lewis believes that son's Planetary Science Institute. the planets formed out of gases that cooled Located about midway between the and condensed. At some point, billions of Earth and the Sun, Mercury is a "truly bi- years ago, the sun flared up briefly, blast- zarre" planet. Its rock cmst is unusually ing away many gases. According to Lewis's thin; a "metallic iron core" accounts for theory, there should not be any sulfur, or 70 percent of the planet's weight. anything like it, on Mercury. The most surprising discovery made by A more recent theory, propounded by Mariner 10 was that the tiny planet has a George Wetherill of the Carnegie Institu- magnetic field, like Earth's but much tion, is that the solar system emerged from weaker. -
Three-Body Capture of Irregular Satellites: Application to Jupiter
Icarus 208 (2010) 824–836 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Three-body capture of irregular satellites: Application to Jupiter Catherine M. Philpott a,*, Douglas P. Hamilton a, Craig B. Agnor b a Department of Astronomy, University of Maryland, College Park, MD 20742-2421, USA b Astronomy Unit, School of Mathematical Sciences, Queen Mary University of London, London E14NS, UK article info abstract Article history: We investigate a new theory of the origin of the irregular satellites of the giant planets: capture of one Received 19 October 2009 member of a 100-km binary asteroid after tidal disruption. The energy loss from disruption is sufficient Revised 24 March 2010 for capture, but it cannot deliver the bodies directly to the observed orbits of the irregular satellites. Accepted 26 March 2010 Instead, the long-lived capture orbits subsequently evolve inward due to interactions with a tenuous cir- Available online 7 April 2010 cumplanetary gas disk. We focus on the capture by Jupiter, which, due to its large mass, provides a stringent test of our model. Keywords: We investigate the possible fates of disrupted bodies, the differences between prograde and retrograde Irregular satellites captures, and the effects of Callisto on captured objects. We make an impulse approximation and discuss Jupiter, Satellites Planetary dynamics how it allows us to generalize capture results from equal-mass binaries to binaries with arbitrary mass Satellites, Dynamics ratios. Jupiter We find that at Jupiter, binaries offer an increase of a factor of 10 in the capture rate of 100-km objects as compared to single bodies, for objects separated by tens of radii that approach the planet on relatively low-energy trajectories. -
Complex Life, by Jove!
Complex Life, By Jove! By: Leslie Mullen The gas giants in our solar system. From left: Neptune, Uranus, Saturn, and Jupiter. Credit: NASA One of the tenets of astrology is that the positions of the planets affect us. For instance, the position of the planet Jupiter in your chart is supposed to indicate good luck for a certain aspect of your life. In an eerie echo of astrology, some scientists are now saying that the position of Jupiter in our solar system was very good luck for life on Earth. Jupiter is about 5 astronomical units (AU) away from the Sun − far enough away from Earth to not have interfered with the development of our planet, and yet close enough to gravitationally deflect asteroids and comets, limiting the number of dangerous impacts. Impacts by asteroids and comets can create cataclysmic events that destroy life − witness the demise of the dinosaurs 65 million years ago, widely believed to have been brought about by a "killer" asteroid impact. Without Jupiter, instead of being hit with a killer asteroid every hundred million years or so, we´d get one every 10,000 years. This reduction in impacts enabled the Earth to develop both simple and complex forms of life. But gas giant planets like Jupiter don´t always help in the development of complex life. Consider, for instance, that while Jupiter deflects many asteroids away from Earth, it also is responsible for most of the asteroids in the first place. When planetesimals were clumping together to form the terrestrial planets, the gravitational influence of Jupiter prevented a fifth planet from forming. -
Deep Earth. (M)
DOCUMENT RESUME ED 250 199 SE 045 178 TITLE The Earth's Core: How Does It Work? Perspectives in Science. Number 1. v INSTITUTION Carnegie Institution of Washington, Washington, DC.h PUB DATE 84 ; ,NOTE 35p. AVAILABLE FROMCarnegie Institution of Washington, 1530 P Street, NW, Washington, DC 20005 ($1.00). .PUB TIME Viewpoints, (120) EDRS PRICE MF01 Plus Postage. PC Not Available froniEDRS. DESCRIPTORS *College Science; *Geology; *Geophysics; Higher Education; High Schools;- Matter; Models; *Science Experiments; *Scientific Research; Secondary School Science; *Seismology IDENTIFIERS *Core (Earth Structure) ABSTRACT a Various research studies designed to enhance knowledge about the earth's core are discussed. Areas addressed includes (1) the discovery of the earth'score; (2) experimental approaches used .in studying the earth's core (including shock-wave everiments and experiments, at high static pressures), the search for the core's light elements, the possible presence of potassium in the core, and use of the diamond cell for investigating thecore;. (3) seismic explorations of the core; (4) inhomogeneities at the core-mantle boundary; (5) terrestrial magnetism and the outer core; and (6) theories of inner -earth structurk from the'perspective of solar system history. Studies of the earth's mantle which may provide additional information about the earth's core are also discussed. They include laboratory experiments with mantle materials and modeling of mantle structure at the Carnegie Institution's Department L_____of____Terreittrial Magnetism. It is poin04 out that althoughmany questions about the earth's core are still unanswered, the promise of new research tools is vast. Favored bfadvances in computer modeling and in techniques for experiments at Nary high presiure, today's scientists seem well-positioned to address these, questions but the deep earth. -
Obituaries Prepared by the Historical Astronomy Division
1274 Obituaries Prepared by the Historical Astronomy Division WULFF-DIETER HEINTZ, 1930-2006 also gained practical training in meridian circles and position Wulff Dieter Heintz, Professor Emeritus of Astronomy at micrometers, and learned to make binary star observations Swarthmore College, passed away at his home on 10 June with the old Fraunhofer refractor ͑1835͒ of the Munich Ob- 2006, following a two-year battle with lung cancer. He had servatory. It was here that his passion for binary stars was turned seventy-six just one week earlier. Wulff was a leading born. authority on visual double stars and also a chess master. A In 1953, Munich University awarded Wulff the degree of prominent educator, researcher, and scholar, Wulff was Doktor rerum naturalis in astronomy, which he completed noted for being both succinct and meticulous in everything under the direction of Felix Schmeidler. Wulff was almost he did. immediately recruited by the Munich University Observatory Wulff Heintz was born on 3 June 1930 in WXrzburg ͑Ba- to serve as the Scientific Assistant at the Southern Station in varia͒, Germany. Naturally left-handed, his elementary Mount Stromlo, Australia. He worked at Mount Stromlo school teachers forced him to learn to write ‘‘correctly’’ us- from 1954 to 1955, then returned to Munich to serve as ing his right hand, and so he became ambidextrous. During Research Officer from 1956-69, during which time he visited the 1930s, Wulff’s family saw the rise of Adolf Hitler and both the United Kingdom and the United States. Wulff was lived under the repressive Nazi regime. -
2006 Fall.Pdf
THE NEWSLETTER OF THE CARNEGIE INSTITUTION [FALL 2006] [PAGE 3] [PAGE 10] [PAGE 11] Inside 3 Embryology Alumnus Andrew Z. Fire Shares Nobel Prize 4 Tipping the Mass Scales at the Edge of the Visible Universe 6 Small-scale Logging Blazes the Trail for Deforestation 7 Sugar Metabolism Tracked in Living Plant Tissues in Real Time 9 Minerals Go “Dark” Near Earth’s Core 10 More Awards: Two Other Carnegie Luminaries Honored 12 Mice Aid the Study of Human Eye Cancer 13 Carnegie’s George West Wetherill, Father of Earth-Formation Models, Dies at 80 14 Why Waves Go Wacky at Earth’s Center 14 Three New “Trojan” Asteroids Found Sharing Neptune’s Orbit 16 In Brief 20 David Greenewalt Building Dedicated at Broad Branch Road Ȝ Ȝ Ȝ Ȝ Ȝ Ȝ Ȝ DEPARTMENT GEOPHYSICAL DEPARTMENT THE DEPARTMENT DEPARTMENT CASE/ OF EMBRYOLOGY LABORATORY OF GLOBAL OBSERVATORIES OF PLANT OF TERRESTRIAL FIRST LIGHT ECOLOGY BIOLOGY MAGNETISM 2 As an institution founded with a mandate to conduct basic scientific research, Carnegie can often appear removed from the problems that dominate our headlines. Indeed, stories of violent crime, scandal, and complicated political problems can sometimes seem like dispatches from another frontier. The institution also seems distant from people who tackle issues of social gravity. One could easily conclude that Carnegie’s explorations of the nature of life, the Earth, and the cosmos have little to do with issues that are germane to our daily lives. Is this perceived gulf as wide as it seems? As a nonscientist, I am struck by how the passage of time can illuminate the value of basic research.