Exploration of the Planets – 1971
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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. -
Lecture 12 the Rings and Moons of the Outer Planets October 15, 2018
Lecture 12 The Rings and Moons of the Outer Planets October 15, 2018 1 2 Rings of Outer Planets • Rings are not solid but are fragments of material – Saturn: Ice and ice-coated rock (bright) – Others: Dusty ice, rocky material (dark) • Very thin – Saturn rings ~0.05 km thick! • Rings can have many gaps due to small satellites – Saturn and Uranus 3 Rings of Jupiter •Very thin and made of small, dark particles. 4 Rings of Saturn Flash movie 5 Saturn’s Rings Ring structure in natural color, photographed by Cassini probe July 23, 2004. Click on image for Astronomy Picture of the Day site, or here for JPL information 6 Saturn’s Rings (false color) Photo taken by Voyager 2 on August 17, 1981. Click on image for more information 7 Saturn’s Ring System (Cassini) Mars Mimas Janus Venus Prometheus A B C D F G E Pandora Enceladus Epimetheus Earth Tethys Moon Wikipedia image with annotations On July 19, 2013, in an event celebrated the world over, NASA's Cassini spacecraft slipped into Saturn's shadow and turned to image the planet, seven of its moons, its inner rings -- and, in the background, our home planet, Earth. 8 Newly Discovered Saturnian Ring • Nearly invisible ring in the plane of the moon Pheobe’s orbit, tilted 27° from Saturn’s equatorial plane • Discovered by the infrared Spitzer Space Telescope and announced 6 October 2009 • Extends from 128 to 207 Saturnian radii and is about 40 radii thick • Contributes to the two-tone coloring of the moon Iapetus • Click here for more info about the artist’s rendering 9 Rings of Uranus • Uranus -- rings discovered through stellar occultation – Rings block light from star as Uranus moves by. -
Predictable Patterns in Planetary Transit Timing Variations and Transit Duration Variations Due to Exomoons
Astronomy & Astrophysics manuscript no. ms c ESO 2016 June 21, 2016 Predictable patterns in planetary transit timing variations and transit duration variations due to exomoons René Heller1, Michael Hippke2, Ben Placek3, Daniel Angerhausen4, 5, and Eric Agol6, 7 1 Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany; [email protected] 2 Luiter Straße 21b, 47506 Neukirchen-Vluyn, Germany; [email protected] 3 Center for Science and Technology, Schenectady County Community College, Schenectady, NY 12305, USA; [email protected] 4 NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA; [email protected] 5 USRA NASA Postdoctoral Program Fellow, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA 6 Astronomy Department, University of Washington, Seattle, WA 98195, USA; [email protected] 7 NASA Astrobiology Institute’s Virtual Planetary Laboratory, Seattle, WA 98195, USA Received 22 March 2016; Accepted 12 April 2016 ABSTRACT We present new ways to identify single and multiple moons around extrasolar planets using planetary transit timing variations (TTVs) and transit duration variations (TDVs). For planets with one moon, measurements from successive transits exhibit a hitherto unde- scribed pattern in the TTV-TDV diagram, originating from the stroboscopic sampling of the planet’s orbit around the planet–moon barycenter. This pattern is fully determined and analytically predictable after three consecutive transits. The more measurements become available, the more the TTV-TDV diagram approaches an ellipse. For planets with multi-moons in orbital mean motion reso- nance (MMR), like the Galilean moon system, the pattern is much more complex and addressed numerically in this report. -
Cassini RADAR Sequence Planning and Instrument Performance Richard D
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 47, NO. 6, JUNE 2009 1777 Cassini RADAR Sequence Planning and Instrument Performance Richard D. West, Yanhua Anderson, Rudy Boehmer, Leonardo Borgarelli, Philip Callahan, Charles Elachi, Yonggyu Gim, Gary Hamilton, Scott Hensley, Michael A. Janssen, William T. K. Johnson, Kathleen Kelleher, Ralph Lorenz, Steve Ostro, Member, IEEE, Ladislav Roth, Scott Shaffer, Bryan Stiles, Steve Wall, Lauren C. Wye, and Howard A. Zebker, Fellow, IEEE Abstract—The Cassini RADAR is a multimode instrument used the European Space Agency, and the Italian Space Agency to map the surface of Titan, the atmosphere of Saturn, the Saturn (ASI). Scientists and engineers from 17 different countries ring system, and to explore the properties of the icy satellites. have worked on the Cassini spacecraft and the Huygens probe. Four different active mode bandwidths and a passive radiometer The spacecraft was launched on October 15, 1997, and then mode provide a wide range of flexibility in taking measurements. The scatterometer mode is used for real aperture imaging of embarked on a seven-year cruise out to Saturn with flybys of Titan, high-altitude (around 20 000 km) synthetic aperture imag- Venus, the Earth, and Jupiter. The spacecraft entered Saturn ing of Titan and Iapetus, and long range (up to 700 000 km) orbit on July 1, 2004 with a successful orbit insertion burn. detection of disk integrated albedos for satellites in the Saturn This marked the start of an intensive four-year primary mis- system. Two SAR modes are used for high- and medium-resolution sion full of remote sensing observations by a dozen instru- (300–1000 m) imaging of Titan’s surface during close flybys. -
Abstracts of the 50Th DDA Meeting (Boulder, CO)
Abstracts of the 50th DDA Meeting (Boulder, CO) American Astronomical Society June, 2019 100 — Dynamics on Asteroids break-up event around a Lagrange point. 100.01 — Simulations of a Synthetic Eurybates 100.02 — High-Fidelity Testing of Binary Asteroid Collisional Family Formation with Applications to 1999 KW4 Timothy Holt1; David Nesvorny2; Jonathan Horner1; Alex B. Davis1; Daniel Scheeres1 Rachel King1; Brad Carter1; Leigh Brookshaw1 1 Aerospace Engineering Sciences, University of Colorado Boulder 1 Centre for Astrophysics, University of Southern Queensland (Boulder, Colorado, United States) (Longmont, Colorado, United States) 2 Southwest Research Institute (Boulder, Connecticut, United The commonly accepted formation process for asym- States) metric binary asteroids is the spin up and eventual fission of rubble pile asteroids as proposed by Walsh, Of the six recognized collisional families in the Jo- Richardson and Michel (Walsh et al., Nature 2008) vian Trojan swarms, the Eurybates family is the and Scheeres (Scheeres, Icarus 2007). In this theory largest, with over 200 recognized members. Located a rubble pile asteroid is spun up by YORP until it around the Jovian L4 Lagrange point, librations of reaches a critical spin rate and experiences a mass the members make this family an interesting study shedding event forming a close, low-eccentricity in orbital dynamics. The Jovian Trojans are thought satellite. Further work by Jacobson and Scheeres to have been captured during an early period of in- used a planar, two-ellipsoid model to analyze the stability in the Solar system. The parent body of the evolutionary pathways of such a formation event family, 3548 Eurybates is one of the targets for the from the moment the bodies initially fission (Jacob- LUCY spacecraft, and our work will provide a dy- son and Scheeres, Icarus 2011). -
The Asteroid Florence 3122
The Asteroid Florence 3122 By Mohammad Hassan BACKGROUND • Asteroid 3122 Florence is a stony trinary asteroid of the Amor group. • It was discovered on March 2nd 1981 by Astronomer Schelte J. ”Bobby” Bus at Siding Spring Observatory. It was named in honor of Florence Nightingdale, the founder of modern nursing. • It has an approximate diameter of 5 kilometers. It also orbits the Sun at a distance of 1.0-2.5 astronomical unit once every 2 years and 4 months (859 days). • Florence rotates once every 2.4 hours, a result that was determined previously from optical measurements of the asteroid’s brightness variations. • THE MOST FASINATING THING IS THAT IT HAS TWO MOONS, HENCE WHY IT IS A PART OF THE AMOR GROUP. • The reason why this Asteroid 3122 Florence is important is because it is a near-earth object with the potential of hitting the earth in the future time. Concerns? • Florence 3122 was classified as a potentially hazardous object because of its minimum orbit intersection distance (less than 0.05 AU). This means that Florence 3122 has the potential to make close approaches to the Earth. • Another thing to keep in mind was that Florence 3122 minimum distance from us was 7 millions of km, about 20 times farthest than our moon. What actually happened? • On September 1st, 2017, Florence passed 0.047237 AU from Earth. That is about 7,000 km or 4,400 miles. • From Earth’s perspective, it brightened to apparent magnitude 8.5. It was also visible in small telescopes for several nights as it moved from south to north through the constellations. -
Linking the Solar System and Extrasolar Planetary
Linking the Solar System and Extrasolar Planetary Systems with Radar Astronomy Infrastructure for \Ground Truth" Comparison Authors: Joseph Lazio (Jet Propulsion Laboratory, California Institute of Technology), Am- ber Bonsall (Green Bank Observatory), Marina Brozovic (Jet Propulsion Laboratory, California Institute of Technology), Jon D. Giorgini (Jet Propulsion Laboratory, California Institute of Tech- nology), Karen O'Neil (Green Bank Observatory) Edgard Rivera-Valentin (Lunar & Planetary Institute), Anne Katariina Virkki (Univ. Central Florida) Endorsers: Francisco Cordova (Arecibo Observatory; Univ. Central Florida), Michael Busch (SETI Institute), Bruce A. Campbell (Smithsonian Institution), P. G. Edwards (CSIRO Astron- omy & Space Science), Yanga R. Fernandez (Univ. Central Florida), Ed Kruzins (Canberra Deep Space Communications Center), Noemi Pinilla-Alonso (Univ. Central Florida), Martin A. Slade (Jet Propulsion Laboratory, California Institute of Technology), F. C. F. Venditti (Univ. Central Florida) Point of Contact: Joseph Lazio, 818-354-4198; [email protected] (Left) Planetary radar image of Dione Regio on Venus. White arrows indicate radar- bright features that potentially represent debris from previous volcanic eruptions on Earth's twin planet. (Campbell et al. 2017) (Right) Planetary radar image of the near- Earth asteroid 2017 BQ6, acquired by the Goldstone Solar System Radar, showing sharp facets on this object. Near-Earth asteroids display a range of surface features, from which evolution and collisional processes occurring in the Sun's debris disk can be constrained. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The Arecibo Planetary Radar Program is supported by the National Aeronautics and Space Administration's Near-Earth Object Observa- tions Program through Grant No. -
Low Velocity Impacts Mars's Inner Moon, Phobos, Is Located Deep In
Phobos: Low Velocity Impacts Mars’s inner moon, Phobos, is located deep in the planet’s gravity well and orbits far below the planet’s synchronous orbit. Images of the surface of Phobos, in particular from Viking Orbiter 1, MGS, MRO, and MEX, reveal a rich collisional history, including fresh‐looking impact craters and subdued older ones, very large impact structures (compared to the size of Phobos), such as Stickney, and much smaller ones. Sources of impactors colliding with Phobos include a priori: A) Impactors from outside the martian system (asteroids, comets, and fragments thereof); B) Impactors from Mars itself (ejecta from large impacts on Mars); and C) Impactors from Mars orbit, including impact ejecta launched from Deimos and ejecta launched from, and reintercepted by, Phobos. In addition to individual craters on Phobos, the networks of grooves on this moon have also been attributed in part or in whole to impactors from some of these sources, particularly B. We report the preliminary results of a systematic survey of the distribution, morphology, albedo, and color characteristics of fresh impact craters and associated ejecta deposits on Phobos. Considering that the different potential impactor sources listed above are expected to display distinct dominant compositions and different characteristic impact velocity regimes, we identify specific craters on Phobos that are more likely the result of low velocity impacts by impactors derived from Mars orbit than from any alternative sources. Our finding supports the hypothesis that the spectrally “Redder Unit” on Phobos may be a superficial veneer of accreted ejecta from Deimos, and that Phobos’s bulk might be distinct in composition from Deimos. -
Greek Myths Student Sample
CONTENTS Why Study Greek Mythology? ......................................................................................................................................5 How to Use This Guide ...................................................................................................................................................6 Lesson 1: Olden Times, Gaea, The Titans, Cronus (pp. 9-15) ....................................................................................8 Lesson 2: Zeus and his Family (pp. 16-21) .................................................................................................................10 Lesson 3: Twelve Golden Thrones (pp. 22-23) ...........................................................................................................12 Lesson 4: Hera, Hephaestus (pp. 24-29) .....................................................................................................................14 Lesson 5: Aphrodite, Ares, Athena (pp. 30-37) ..........................................................................................................16 Review Lesson: Lessons 1-5 ........................................................................................................................................18 Lesson 6: Poseidon, Apollo (pp. 38-43) .......................................................................................................................26 Lesson 7: Artemis, Hermes (pp. 44-55) .......................................................................................................................28 -
Possibilities for Life in the Inner Solar System We Will Now Begin Going
Possibilities for Life in the Inner Solar System We will now begin going systematically through other possible locations for life (not necessarily intelligent life) in the Solar System. Some possibilities are obvious: Mars and Jupiter’s moon Europa are examples. However, in the interest of continuing open-mindedness, in this lecture we will discuss our Moon, Mercury, the moons of Mars, and Venus. Next lec- ture will focus on Mars, which has a real possibility of having had life at one point, or even having it now below the surface. As we discuss each object, we will keep in mind our basic requirements for life: chemical building blocks, liquids in some place, energy, and stability. Our Moon The Moon is the closest astronomical object to the Earth, and the only one on which we can see significant surface features with our naked eyes (the Sun is too bright, and everything else is pointlike or, like the Andromeda galaxy, too dim). As a result, it has from time immemorial inspired many fanciful notions, including that the Moon is inhabited. In fact, life on the Moon was the subject of one of the most famous hoaxes ever perpetrated. On August 25, 1835 the New York Sun, a small newspaper with a daily circulation of about 4,000, printed a remarkable story on page 2. According to them Sir John Herschel (son of the discoverer of Uranus) had been observing the Moon with a new telescope based in South Africa. The results were astounding. He had seen herds of bison, many beavers, a rich variety of plants, and, most intriguingly, traces of artificial features with smoke coming out of them. -
Michael W. Busch Updated June 27, 2019 Contact Information
Curriculum Vitae: Michael W. Busch Updated June 27, 2019 Contact Information Email: [email protected] Telephone: 1-612-269-9998 Mailing Address: SETI Institute 189 Bernardo Ave, Suite 200 Mountain View, CA 94043 USA Academic & Employment History BS Physics & Astrophysics, University of Minnesota, awarded May 2005. PhD Planetary Science, Caltech, defended April 5, 2010. JPL Planetary Science Summer School, July 2006. Hertz Foundation Graduate Fellow, September 2007 to June 2010. Postdoctoral Researcher, University of California Los Angeles, August 2010 – August 2011. Jansky Fellow, National Radio Astronomy Observatory, August 2011 – August 2014. Visiting Scholar, University of Colorado Boulder, July – August 2012. Research Scientist, SETI Institute, August 2013 – present. Current Funding Sources: NASA Near Earth Object Observations. Research Interests: • Shapes, spin states, trajectories, internal structures, and histories of asteroids. • Identifying and characterizing targets for both robotic and human spacecraft missions. • Ruling out potential future asteroid-Earth impacts. • Radio and radar astronomy techniques. Selected Recent Papers: Marshall, S.E., and 24 colleagues, including Busch, M.W., 2019. Shape modeling of potentially hazardous asteroid (85989) 1999 JD6 from radar and lightcurve data, Icarus submitted. Reddy, V., and 69 colleagues, including Busch, M.W., 2019. Near-Earth asteroid 2012 TC4 campaign: results from global planetary defense exercise, Icarus 326, 133-150. Brozović, M., and 16 colleagues, including Busch, M.W., 2018. Goldstone and Arecibo radar observations of (99942) Apophis in 2012-2013, Icarus 300, 115-128. Brozović, M., and 19 colleagues, including Busch, M.W., 2017. Goldstone radar evidence for short-axis mode non-principal axis rotation of near-Earth asteroid (214869) 2007 PA8. Icarus 286, 314-329. -
Travel Times by Spacecraft Around the Solar System 3
Travel Times by Spacecraft Around the Solar System 3 Most science fiction stories often have spaceships with powerful, or exotic, rockets that can let space travelers visit the distant planets in less than a day’s journey. The sad thing is that we are not quite there in the Real World. This is because our solar system is so vast, and our rockets can’t produce quite enough speed to make journeys short. NASA has been working on this problem for over 50 years and has come up with many possible solutions. Each one is more expensive than just using ordinary fuels and engines like the ones used on most rockets! Problem 1 – The entire International Space Station orbits Earth at a speed of 28,000 kilometers per hour (17,000 mph). At this speed, how many days would it take to travel to the sun from Earth, located at a distance of 149 million kilometers? Problem 2 – The planet Neptune is located 4.5 billion kilometers from Earth. How many years would it take a rocket traveling at the speed of the International Space Station to make this journey? Problem 3 – The fastest unmanned spacecraft, Helios-2, traveled at a speed of 253,000 km/hr. In the table below, use proportional math to fill in the travel times from the sun to each planet traveling at the speed of Helios-2. Give your answers to the nearest tenth in appropriate units of days or years. Planet Distance in Time millions of kilometers Mercury 57 Venus 108 Earth 149 Mars 228 Jupiter 780 Saturn 1437 Uranus 2871 Neptune 4530 Space Math http://spacemath.gsfc.nasa.gov Answer Key 3 Problem 1 – The entire International Space Station orbits Earth at a speed of 28,000 kilometers per hour (17,000 mph).