On the Detection of Exomoons in Photometric Time Series
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Lab 7: Gravity and Jupiter's Moons
Lab 7: Gravity and Jupiter's Moons Image of Galileo Spacecraft Gravity is the force that binds all astronomical structures. Clusters of galaxies are gravitationally bound into the largest structures in the Universe, Galactic Superclusters. The galaxies themselves are held together by gravity, as are all of the star systems within them. Our own Solar System is a collection of bodies gravitationally bound to our star, Sol. Cutting edge science requires the use of Einstein's General Theory of Relativity to explain gravity. But the interactions of the bodies in our Solar System were understood long before Einstein's time. In chapter two of Chaisson McMillan's Astronomy Today, you went over Kepler's Laws. These laws of gravity were made to describe the interactions in our Solar System. P2=a3/M Where 'P' is the orbital period in Earth years, the time for the body to make one full orbit. 'a' is the length of the orbit's semi-major axis, for nearly circular orbits the orbital radius. 'M' is the total mass of the system in units of Solar Masses. Jupiter System Montage picture from NASA ID = PIA01481 Jupiter has over 60 moons at the last count, most of which are asteroids and comets captured from Written by Meagan White and Paul Lewis Page 1 the Asteroid Belt. When Galileo viewed Jupiter through his early telescope, he noticed only four moons: Io, Europa, Ganymede, and Callisto. The Jupiter System can be thought of as a miniature Solar System, with Jupiter in place of the Sun, and the Galilean moons like planets. -
The Geology of the Rocky Bodies Inside Enceladus, Europa, Titan, and Ganymede
49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083) 2905.pdf THE GEOLOGY OF THE ROCKY BODIES INSIDE ENCELADUS, EUROPA, TITAN, AND GANYMEDE. Paul K. Byrne1, Paul V. Regensburger1, Christian Klimczak2, DelWayne R. Bohnenstiehl1, Steven A. Hauck, II3, Andrew J. Dombard4, and Douglas J. Hemingway5, 1Planetary Research Group, Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA ([email protected]), 2Department of Geology, University of Georgia, Athens, GA 30602, USA, 3Department of Earth, Environmental, and Planetary Sciences, Case Western Reserve University, Cleveland, OH 44106, USA, 4Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA, 5Department of Earth & Planetary Science, University of California Berkeley, Berkeley, CA 94720, USA. Introduction: The icy satellites of Jupiter and horizontal stresses, respectively, Pp is pore fluid Saturn have been the subjects of substantial geological pressure (found from (3)), and μ is the coefficient of study. Much of this work has focused on their outer friction [12]. Finally, because equations (4) and (5) shells [e.g., 1–3], because that is the part most readily assess failure in the brittle domain, we also considered amenable to analysis. Yet many of these satellites ductile deformation with the relation n –E/RT feature known or suspected subsurface oceans [e.g., 4– ε̇ = C1σ exp , (6) 6], likely situated atop rocky interiors [e.g., 7], and where ε̇ is strain rate, C1 is a constant, σ is deviatoric several are of considerable astrobiological significance. stress, n is the stress exponent, E is activation energy, R For example, chemical reactions at the rock–water is the universal gas constant, and T is temperature [13]. -
Galileo and the Telescope
Galileo and the Telescope A Discussion of Galileo Galilei and the Beginning of Modern Observational Astronomy ___________________________ Billy Teets, Ph.D. Acting Director and Outreach Astronomer, Vanderbilt University Dyer Observatory Tuesday, October 20, 2020 Image Credit: Giuseppe Bertini General Outline • Telescopes/Galileo’s Telescopes • Observations of the Moon • Observations of Jupiter • Observations of Other Planets • The Milky Way • Sunspots Brief History of the Telescope – Hans Lippershey • Dutch Spectacle Maker • Invention credited to Hans Lippershey (c. 1608 - refracting telescope) • Late 1608 – Dutch gov’t: “ a device by means of which all things at a very great distance can be seen as if they were nearby” • Is said he observed two children playing with lenses • Patent not awarded Image Source: Wikipedia Galileo and the Telescope • Created his own – 3x magnification. • Similar to what was peddled in Europe. • Learned magnification depended on the ratio of lens focal lengths. • Had to learn to grind his own lenses. Image Source: Britannica.com Image Source: Wikipedia Refracting Telescopes Bend Light Refracting Telescopes Chromatic Aberration Chromatic aberration limits ability to distinguish details Dealing with Chromatic Aberration - Stop Down Aperture Galileo used cardboard rings to limit aperture – Results were dimmer views but less chromatic aberration Galileo and the Telescope • Created his own (3x, 8-9x, 20x, etc.) • Noted by many for its military advantages August 1609 Galileo and the Telescope • First observed the -
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. -
The Jovian Planets (Gas Giants) Discoveries
The Jovian Planets (Gas Giants) Discoveries Saturn Jupiter Jupiter and Saturn known to ancient astronomers. Uranus discovered in 1781 by Sir William Herschel (England). Neptune discovered in 1845 by Johann Galle (Germany). Predicted to exist by John Adams and Urbain Leverrier because of irregularities in Uranus' orbit. Almost discovered by Galileo in 1613 Uranus Neptune (roughly to scale) Remember that compared to Terrestrial planets, Jovian planets: Orbital Properties: Distance from Sun Orbital Period are massive (AU) (years) are less dense (0.7 – 1.3 g/cm3) Jupiter 5.2 11.9 are mostly gas (and liquid) Saturn 9.5 29.4 rotate fast (9 - 17 hours rotation periods) Uranus 19.2 84 have rings and many moons Neptune 30.1 164 Known Moons Mass (MEarth) Radius (REarth) Major Missions: Launch Planets visited Jupiter 318 11 63 Voyager 1 1977 Jupiter, Saturn (0.001 MSun) Saturn 95 9.5 50 Voyager 2 1979 Jupiter, Saturn, Uranus, Neptune Uranus 15 4 27 Galileo 1989 Jupiter Neptune 17 3.9 13 Cassini 1997 Jupiter, Saturn Jupiter's Atmosphere Composition: mostly H, some He, traces of other elements (true for all Jovians). Gravity strong enough to retain even light elements. Mostly molecular. Altitude 0 km defined as top of troposphere (cloud layer) Ammonia (NH3) ice gives white colors. Ammonium hydrosulfide Optical – colors dictated Infrared - traces heat in (NH4SH) ice should form by how molecules atmosphere. here, somehow giving red, reflect sunlight yellow, brown colors. Water ice layer not seen due to higher layers. So white colors from cooler, higher clouds, brown and red from warmer, lower clouds. -
Exomoon Habitability Constrained by Illumination and Tidal Heating
submitted to Astrobiology: April 6, 2012 accepted by Astrobiology: September 8, 2012 published in Astrobiology: January 24, 2013 this updated draft: October 30, 2013 doi:10.1089/ast.2012.0859 Exomoon habitability constrained by illumination and tidal heating René HellerI , Rory BarnesII,III I Leibniz-Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany, [email protected] II Astronomy Department, University of Washington, Box 951580, Seattle, WA 98195, [email protected] III NASA Astrobiology Institute – Virtual Planetary Laboratory Lead Team, USA Abstract The detection of moons orbiting extrasolar planets (“exomoons”) has now become feasible. Once they are discovered in the circumstellar habitable zone, questions about their habitability will emerge. Exomoons are likely to be tidally locked to their planet and hence experience days much shorter than their orbital period around the star and have seasons, all of which works in favor of habitability. These satellites can receive more illumination per area than their host planets, as the planet reflects stellar light and emits thermal photons. On the contrary, eclipses can significantly alter local climates on exomoons by reducing stellar illumination. In addition to radiative heating, tidal heating can be very large on exomoons, possibly even large enough for sterilization. We identify combinations of physical and orbital parameters for which radiative and tidal heating are strong enough to trigger a runaway greenhouse. By analogy with the circumstellar habitable zone, these constraints define a circumplanetary “habitable edge”. We apply our model to hypothetical moons around the recently discovered exoplanet Kepler-22b and the giant planet candidate KOI211.01 and describe, for the first time, the orbits of habitable exomoons. -
OCEANOGRAPHY an Additional 1.4 Tg of Carbon Per Year Atmospheric CO2 Concentrations from Ice Loss and Ocean Life Over This Period
research highlights OCEANOGRAPHY an additional 1.4 Tg of carbon per year atmospheric CO2 concentrations from Ice loss and ocean life over this period. A rise in phytoplankton Antarctic ice cores. They found that Glob. Biogeochem. Cycles http://doi.org/p27 (2013) productivity in the surface waters of the two younger periods of enhanced the Laptev, East Siberian, Chukchi and mixing coincided with a steep increase in Beaufort seas was responsible for the atmospheric CO2 levels, and the oldest with increase in carbon uptake. In contrast, net a small, temporary rise. carbon uptake declined in the Barents Sea, The team concluded that enhanced where a warming-induced outgassing of vertical mixing in these intervals brought surface-water CO2 countered the rise in CO2-rich waters from the deep ocean to the primary production. surface, allowing CO2 to escape from these The findings suggest that the continued upwelled waters to the atmosphere. AN decline of Arctic sea ice cover could be accompanied by a rise in the oceanic uptake PLANETARY SCIENCE of carbon dioxide, although uncertainties Weighing Phobos in the response of physical, chemical and Icarus http://doi.org/p26 (2013) biological processes to sea ice loss hinder reliable predictions at this stage. AA PALAEOCEANOGRAPHY Southern upwelling Nature Commun. 4, 2758 (2013). At the end of the last glacial period about 20,000 years ago, atmospheric CO2 concentrations rose in several steps. Radiocarbon measurements from a marine sediment core suggest that the upwelling of © FRANS LANTING STUDIO / ALAMY © FRANS LANTING STUDIO carbon-rich waters in the Southern Ocean contributed to the CO2 rise. -
JUICE Red Book
ESA/SRE(2014)1 September 2014 JUICE JUpiter ICy moons Explorer Exploring the emergence of habitable worlds around gas giants Definition Study Report European Space Agency 1 This page left intentionally blank 2 Mission Description Jupiter Icy Moons Explorer Key science goals The emergence of habitable worlds around gas giants Characterise Ganymede, Europa and Callisto as planetary objects and potential habitats Explore the Jupiter system as an archetype for gas giants Payload Ten instruments Laser Altimeter Radio Science Experiment Ice Penetrating Radar Visible-Infrared Hyperspectral Imaging Spectrometer Ultraviolet Imaging Spectrograph Imaging System Magnetometer Particle Package Submillimetre Wave Instrument Radio and Plasma Wave Instrument Overall mission profile 06/2022 - Launch by Ariane-5 ECA + EVEE Cruise 01/2030 - Jupiter orbit insertion Jupiter tour Transfer to Callisto (11 months) Europa phase: 2 Europa and 3 Callisto flybys (1 month) Jupiter High Latitude Phase: 9 Callisto flybys (9 months) Transfer to Ganymede (11 months) 09/2032 – Ganymede orbit insertion Ganymede tour Elliptical and high altitude circular phases (5 months) Low altitude (500 km) circular orbit (4 months) 06/2033 – End of nominal mission Spacecraft 3-axis stabilised Power: solar panels: ~900 W HGA: ~3 m, body fixed X and Ka bands Downlink ≥ 1.4 Gbit/day High Δv capability (2700 m/s) Radiation tolerance: 50 krad at equipment level Dry mass: ~1800 kg Ground TM stations ESTRAC network Key mission drivers Radiation tolerance and technology Power budget and solar arrays challenges Mass budget Responsibilities ESA: manufacturing, launch, operations of the spacecraft and data archiving PI Teams: science payload provision, operations, and data analysis 3 Foreword The JUICE (JUpiter ICy moon Explorer) mission, selected by ESA in May 2012 to be the first large mission within the Cosmic Vision Program 2015–2025, will provide the most comprehensive exploration to date of the Jovian system in all its complexity, with particular emphasis on Ganymede as a planetary body and potential habitat. -
Last Time: Planet Finding
Last Time: Planet Finding • Radial velocity method • Parent star’s Doppler shi • Planet minimum mass, orbital period, semi- major axis, orbital eccentricity • UnAl Kepler Mission, was the method with the most planets Last Time: Planet Finding • Transits – eclipse of the parent star: • Planetary radius, orbital period, semi-major axis • Now the most common way to find planets Last Time: Planet Finding • Direct Imaging • Planetary brightness, distance from parent star at that moment • About 10 planets detected Last Time: Planet Finding • Lensing • Planetary mass and, distance from parent star at that moment • You want to look towards the center of the galaxy where there is a high density of stars Last Time: Planet Finding • Astrometry • Tiny changes in star’s posiAon are not yet measurable • Would give you planet’s mass, orbit, and eccentricity One more important thing to add: • Giant planets (which are easiest to detect) are preferenAally found around stars that are abundant in iron – “metallicity” • Iron is the easiest heavy element to measure in a star • Heavy-element rich planetary systems make planets more easily 13.2 The Nature of Extrasolar Planets Our goals for learning: • What have we learned about extrasolar planets? • How do extrasolar planets compare with planets in our solar system? Measurable Properties • Orbital period, distance, and orbital shape • Planet mass, size, and density • Planetary temperature • Composition Orbits of Extrasolar Planets • Nearly all of the detected planets have orbits smaller than Jupiter’s. • This is a selection effect: Planets at greater distances are harder to detect with the Doppler technique. Orbits of Extrasolar Planets • Orbits of some extrasolar planets are much more elongated (have a greater eccentricity) than those in our solar system. -
The Inner Solar System Is the Name of the Terrestrial Planets and Asteroid
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
THE EARTH's GRAVITY OUTLINE the Earth's Gravitational Field
GEOPHYSICS (08/430/0012) THE EARTH'S GRAVITY OUTLINE The Earth's gravitational field 2 Newton's law of gravitation: Fgrav = GMm=r ; Gravitational field = gravitational acceleration g; gravitational potential, equipotential surfaces. g for a non–rotating spherically symmetric Earth; Effects of rotation and ellipticity – variation with latitude, the reference ellipsoid and International Gravity Formula; Effects of elevation and topography, intervening rock, density inhomogeneities, tides. The geoid: equipotential mean–sea–level surface on which g = IGF value. Gravity surveys Measurement: gravity units, gravimeters, survey procedures; the geoid; satellite altimetry. Gravity corrections – latitude, elevation, Bouguer, terrain, drift; Interpretation of gravity anomalies: regional–residual separation; regional variations and deep (crust, mantle) structure; local variations and shallow density anomalies; Examples of Bouguer gravity anomalies. Isostasy Mechanism: level of compensation; Pratt and Airy models; mountain roots; Isostasy and free–air gravity, examples of isostatic balance and isostatic anomalies. Background reading: Fowler §5.1–5.6; Lowrie §2.2–2.6; Kearey & Vine §2.11. GEOPHYSICS (08/430/0012) THE EARTH'S GRAVITY FIELD Newton's law of gravitation is: ¯ GMm F = r2 11 2 2 1 3 2 where the Gravitational Constant G = 6:673 10− Nm kg− (kg− m s− ). ¢ The field strength of the Earth's gravitational field is defined as the gravitational force acting on unit mass. From Newton's third¯ law of mechanics, F = ma, it follows that gravitational force per unit mass = gravitational acceleration g. g is approximately 9:8m/s2 at the surface of the Earth. A related concept is gravitational potential: the gravitational potential V at a point P is the work done against gravity in ¯ P bringing unit mass from infinity to P. -
Survival of Satellites During the Migration of a Hot Jupiter: the Influence of Tides
EPSC Abstracts Vol. 13, EPSC-DPS2019-1590-1, 2019 EPSC-DPS Joint Meeting 2019 c Author(s) 2019. CC Attribution 4.0 license. Survival of satellites during the migration of a Hot Jupiter: the influence of tides Emeline Bolmont (1), Apurva V. Oza (2), Sergi Blanco-Cuaresma (3), Christoph Mordasini (2), Pierre Auclair-Desrotour (2), Adrien Leleu (2) (1) Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, CH-1290 Sauverny, Switzerland ([email protected]) (2) Physikalisches Institut, Universität Bern, Gesellschaftsstr. 6, 3012, Bern, Switzerland (3) Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA Abstract 2. The model We explore the origin and stability of extrasolar satel- lites orbiting close-in gas giants, by investigating if the Tidal interactions 1 M⊙ satellite can survive the migration of the planet in the 1 MIo protoplanetary disk. To accomplish this objective, we 1 MJup used Posidonius, a N-Body code with an integrated tidal model, which we expanded to account for the migration of the gas giant in a disk. Preliminary re- Inner edge of disk: ain sults suggest the survival of the satellite is rare, which Type 2 migration: !mig would indicate that if such satellites do exist, capture is a more likely process. Figure 1: Schema of the simulation set up: A Io-like satellite orbits around a Jupiter-like planet with a solar- 1. Introduction like host star. Satellites around Hot Jupiters were first thought to be lost by falling onto their planet over Gyr timescales (e.g. [1]). This is due to the low tidal dissipation factor of Jupiter (Q 106, [10]), likely to be caused by the 2.1.