Lecture 2: Course Overview Introduction to the Solar System
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Nicolaus Copernicus: the Loss of Centrality
I Nicolaus Copernicus: The Loss of Centrality The mathematician who studies the motions of the stars is surely like a blind man who, with only a staff to guide him, must make a great, endless, hazardous journey that winds through innumerable desolate places. [Rheticus, Narratio Prima (1540), 163] 1 Ptolemy and Copernicus The German playwright Bertold Brecht wrote his play Life of Galileo in exile in 1938–9. It was first performed in Zurich in 1943. In Brecht’s play two worldviews collide. There is the geocentric worldview, which holds that the Earth is at the center of a closed universe. Among its many proponents were Aristotle (384–322 BC), Ptolemy (AD 85–165), and Martin Luther (1483–1546). Opposed to geocentrism is the heliocentric worldview. Heliocentrism teaches that the sun occupies the center of an open universe. Among its many proponents were Copernicus (1473–1543), Kepler (1571–1630), Galileo (1564–1642), and Newton (1643–1727). In Act One the Italian mathematician and physicist Galileo Galilei shows his assistant Andrea a model of the Ptolemaic system. In the middle sits the Earth, sur- rounded by eight rings. The rings represent the crystal spheres, which carry the planets and the fixed stars. Galileo scowls at this model. “Yes, walls and spheres and immobility,” he complains. “For two thousand years people have believed that the sun and all the stars of heaven rotate around mankind.” And everybody believed that “they were sitting motionless inside this crystal sphere.” The Earth was motionless, everything else rotated around it. “But now we are breaking out of it,” Galileo assures his assistant. -
The Planetary Increase of Brightness During Retrograde Motion: an Explanandum Constructed Ad Explanantem
Studies in History and Philosophy of Science 54 (2015) 90e101 Contents lists available at ScienceDirect Studies in History and Philosophy of Science journal homepage: www.elsevier.com/locate/shpsa The planetary increase of brightness during retrograde motion: An explanandum constructed ad explanantem Christián Carlos Carman National University of Quilmes/CONICET, Roque Sáenz Peña 352, B1876BXD Bernal, Buenos Aires, Argentina article info abstract Article history: In Ancient Greek two models were proposed for explaining the planetary motion: the homocentric Received 5 May 2015 spheres of Eudoxus and the Epicycle and Deferent System. At least in a qualitative way, both models Received in revised form could explain the retrograde motion, the most challenging phenomenon to be explained using circular 17 September 2015 motions. Nevertheless, there is another explanandum: during retrograde motion the planets increase their brightness. It is natural to interpret a change of brightness, i.e., of apparent size, as a change in Keywords: distance. Now, while according to the Eudoxian model the planet is always equidistant from the earth, Epicycle; according to the epicycle and deferent system, the planet changes its distance from the earth, Deferent; fi Homocentric spheres; approaching to it during retrograde motion, just as observed. So, it is usually af rmed that the main ’ Brightness change reason for the rejection of Eudoxus homocentric spheres in favor of the epicycle and deferent system was that the first cannot explain the manifest planetary increase of brightness during retrograde motion, while the second can. In this paper I will show that this historical hypothesis is not as firmly founded as it is usually believed to be. -
Detecting the Yarkovsky Effect Among Near-Earth Asteroids From
Detecting the Yarkovsky effect among near-Earth asteroids from astrometric data Alessio Del Vignaa,b, Laura Faggiolid, Andrea Milania, Federica Spotoc, Davide Farnocchiae, Benoit Carryf aDipartimento di Matematica, Universit`adi Pisa, Largo Bruno Pontecorvo 5, Pisa, Italy bSpace Dynamics Services s.r.l., via Mario Giuntini, Navacchio di Cascina, Pisa, Italy cIMCCE, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universits, UPMC Univ. Paris 06, Univ. Lille, 77 av. Denfert-Rochereau F-75014 Paris, France dESA SSA-NEO Coordination Centre, Largo Galileo Galilei, 1, 00044 Frascati (RM), Italy eJet Propulsion Laboratory/California Institute of Technology, 4800 Oak Grove Drive, Pasadena, 91109 CA, USA fUniversit´eCˆote d’Azur, Observatoire de la Cˆote d’Azur, CNRS, Laboratoire Lagrange, Boulevard de l’Observatoire, Nice, France Abstract We present an updated set of near-Earth asteroids with a Yarkovsky-related semi- major axis drift detected from the orbital fit to the astrometry. We find 87 reliable detections after filtering for the signal-to-noise ratio of the Yarkovsky drift esti- mate and making sure the estimate is compatible with the physical properties of the analyzed object. Furthermore, we find a list of 24 marginally significant detec- tions, for which future astrometry could result in a Yarkovsky detection. A further outcome of the filtering procedure is a list of detections that we consider spurious because unrealistic or not explicable with the Yarkovsky effect. Among the smallest asteroids of our sample, we determined four detections of solar radiation pressure, in addition to the Yarkovsky effect. As the data volume increases in the near fu- ture, our goal is to develop methods to generate very long lists of asteroids with reliably detected Yarkovsky effect, with limited amounts of case by case specific adjustments. -
Deep Space Chronicle Deep Space Chronicle: a Chronology of Deep Space and Planetary Probes, 1958–2000 | Asifa
dsc_cover (Converted)-1 8/6/02 10:33 AM Page 1 Deep Space Chronicle Deep Space Chronicle: A Chronology ofDeep Space and Planetary Probes, 1958–2000 |Asif A.Siddiqi National Aeronautics and Space Administration NASA SP-2002-4524 A Chronology of Deep Space and Planetary Probes 1958–2000 Asif A. Siddiqi NASA SP-2002-4524 Monographs in Aerospace History Number 24 dsc_cover (Converted)-1 8/6/02 10:33 AM Page 2 Cover photo: A montage of planetary images taken by Mariner 10, the Mars Global Surveyor Orbiter, Voyager 1, and Voyager 2, all managed by the Jet Propulsion Laboratory in Pasadena, California. Included (from top to bottom) are images of Mercury, Venus, Earth (and Moon), Mars, Jupiter, Saturn, Uranus, and Neptune. The inner planets (Mercury, Venus, Earth and its Moon, and Mars) and the outer planets (Jupiter, Saturn, Uranus, and Neptune) are roughly to scale to each other. NASA SP-2002-4524 Deep Space Chronicle A Chronology of Deep Space and Planetary Probes 1958–2000 ASIF A. SIDDIQI Monographs in Aerospace History Number 24 June 2002 National Aeronautics and Space Administration Office of External Relations NASA History Office Washington, DC 20546-0001 Library of Congress Cataloging-in-Publication Data Siddiqi, Asif A., 1966 Deep space chronicle: a chronology of deep space and planetary probes, 1958-2000 / by Asif A. Siddiqi. p.cm. – (Monographs in aerospace history; no. 24) (NASA SP; 2002-4524) Includes bibliographical references and index. 1. Space flight—History—20th century. I. Title. II. Series. III. NASA SP; 4524 TL 790.S53 2002 629.4’1’0904—dc21 2001044012 Table of Contents Foreword by Roger D. -
Asteroids + Comets
Datasets for Asteroids and Comets Caleb Keaveney, OpenSpace intern Rachel Smith, Head, Astronomy & Astrophysics Research Lab North Carolina Museum of Natural Sciences 2020 Contents Part 1: Visualization Settings ………………………………………………………… 3 Part 2: Near-Earth Asteroids ………………………………………………………… 5 Amor Asteroids Apollo Asteroids Aten Asteroids Atira Asteroids Potentially Hazardous Asteroids (PHAs) Mars-crossing Asteroids Part 3: Main-Belt Asteroids …………………………………………………………… 12 Inner Main Asteroid Belt Main Asteroid Belt Outer Main Asteroid Belt Part 4: Centaurs, Trojans, and Trans-Neptunian Objects ………………………….. 15 Centaur Objects Jupiter Trojan Asteroids Trans-Neptunian Objects Part 5: Comets ………………………………………………………………………….. 19 Chiron-type Comets Encke-type Comets Halley-type Comets Jupiter-family Comets C 2019 Y4 ATLAS About this guide This document outlines the datasets available within the OpenSpace astrovisualization software (version 0.15.2). These datasets were compiled from the Jet Propulsion Laboratory’s (JPL) Small-Body Database (SBDB) and NASA’s Planetary Data Service (PDS). These datasets provide insights into the characteristics, classifications, and abundance of small-bodies in the solar system, as well as their relationships to more prominent bodies. OpenSpace: Datasets for Asteroids and Comets 2 Part 1: Visualization Settings To load the Asteroids scene in OpenSpace, load the OpenSpace Launcher and select “asteroids” from the drop-down menu for “Scene.” Then launch OpenSpace normally. The Asteroids package is a big dataset, so it can take a few hours to load the first time even on very powerful machines and good internet connections. After a couple of times opening the program with this scene, it should take less time. If you are having trouble loading the scene, check the OpenSpace Wiki or the OpenSpace Support Slack for information and assistance. -
Ice & Stone 2020
Ice & Stone 2020 WEEK 17: APRIL 19-25, 2020 Presented by The Earthrise Institute # 17 Authored by Alan Hale This week in history APRIL 19 20 21 22 23 24 25 APRIL 20, 1910: Comet 1P/Halley passes through perihelion at a heliocentric distance of 0.587 AU. Halley’s 1910 return, which is described in a previous “Special Topics” presentation, was quite favorable, with a close approach to Earth (0.15 AU) and the exhibiting of the longest cometary tail ever recorded. APRIL 20, 2025: NASA’s Lucy mission is scheduled to pass by the main belt asteroid (52246) Donaldjohanson. Lucy is discussed in a previous “Special Topics” presentation. APRIL 19 20 21 22 23 24 25 APRIL 21, 2024: Comet 12P/Pons-Brooks is predicted to pass through perihelion at a heliocentric distance of 0.781 AU. This comet, with a discussion of its viewing prospects for 2024, is a previous “Comet of the Week.” APRIL 19 20 21 22 23 24 25 APRIL 22, 2020: The annual Lyrid meteor shower should be at its peak. Normally this shower is fairly weak, with a peak rate of not much more than 10 meteors per hour, but has been known to exhibit significantly stronger activity on occasion. The moon is at its “new” phase on April 23 this year and thus the viewing circumstances are very good. COVER IMAGE CREDIT: Front and back cover: This artist’s conception shows how families of asteroids are created. Over the history of our solar system, catastrophic collisions between asteroids located in the belt between Mars and Jupiter have formed families of objects on similar orbits around the sun. -
Near Earth Asteroid Rendezvous: Mission Summary 351
Cheng: Near Earth Asteroid Rendezvous: Mission Summary 351 Near Earth Asteroid Rendezvous: Mission Summary Andrew F. Cheng The Johns Hopkins Applied Physics Laboratory On February 14, 2000, the Near Earth Asteroid Rendezvous spacecraft (NEAR Shoemaker) began the first orbital study of an asteroid, the near-Earth object 433 Eros. Almost a year later, on February 12, 2001, NEAR Shoemaker completed its mission by landing on the asteroid and acquiring data from its surface. NEAR Shoemaker’s intensive study has found an average density of 2.67 ± 0.03, almost uniform within the asteroid. Based upon solar fluorescence X-ray spectra obtained from orbit, the abundance of major rock-forming elements at Eros may be consistent with that of ordinary chondrite meteorites except for a depletion in S. Such a composition would be consistent with spatially resolved, visible and near-infrared (NIR) spectra of the surface. Gamma-ray spectra from the surface show Fe to be depleted from chondritic values, but not K. Eros is not a highly differentiated body, but some degree of partial melting or differentiation cannot be ruled out. No evidence has been found for compositional heterogeneity or an intrinsic magnetic field. The surface is covered by a regolith estimated at tens of meters thick, formed by successive impacts. Some areas have lesser surface age and were apparently more recently dis- turbed or covered by regolith. A small center of mass offset from the center of figure suggests regionally nonuniform regolith thickness or internal density variation. Blocks have a nonuniform distribution consistent with emplacement of ejecta from the youngest large crater. -
“Point at Infinity Hape of the World
“Point at Infinity hape of the World Last week, we began a series of posts dedicated to thinking about immortality. If we want to even pretend to think precisely about immortality, we will have to consider some fundamental questions. What does it mean to be immortal? What does it mean to live forever? Are these the same thing? And since immortality is inextricably tied up in one’s relationship with time, we must think about the nature of time itself. Is there a difference between external time and personal time? What is the shape of time? Is time linear? Circular? Finite? Infinite? Of course, we exist not just across time but across space as well, so the same questions become relevant when asked about space. What is the shape of space? Is it finite? Infinite? It is not hard to see how this question would have a significant bearing on our thinking about immortality. In a finite universe (or, more precisely, a universe in which only finitely many different configurations of maer are possible), an immortal being would encounter the same situations over and over again, would think the same thoughts over and over again, would have the same conversations over and over again. Would such a life be desirable? (It is not clear that this repetition would be avoidable even in an infinite universe, but more on that later.) Today, we are going to take a lile historical detour to look at the shape of the universe, a trip that will take us from Ptolemy to Dante to Einstein, a trip that will uncover a remarkable confluence of poetry and physics. -
The Arithmetic of the Spheres
The Arithmetic of the Spheres Je↵ Lagarias, University of Michigan Ann Arbor, MI, USA MAA Mathfest (Washington, D. C.) August 6, 2015 Topics Covered Part 1. The Harmony of the Spheres • Part 2. Lester Ford and Ford Circles • Part 3. The Farey Tree and Minkowski ?-Function • Part 4. Farey Fractions • Part 5. Products of Farey Fractions • 1 Part I. The Harmony of the Spheres Pythagoras (c. 570–c. 495 BCE) To Pythagoras and followers is attributed: pitch of note of • vibrating string related to length and tension of string producing the tone. Small integer ratios give pleasing harmonics. Pythagoras or his mentor Thales had the idea to explain • phenomena by mathematical relationships. “All is number.” A fly in the ointment: Irrational numbers, for example p2. • 2 Harmony of the Spheres-2 Q. “Why did the Gods create us?” • A. “To study the heavens.”. Celestial Sphere: The universe is spherical: Celestial • spheres. There are concentric spheres of objects in the sky; some move, some do not. Harmony of the Spheres. Each planet emits its own unique • (musical) tone based on the period of its orbital revolution. Also: These tones, imperceptible to our hearing, a↵ect the quality of life on earth. 3 Democritus (c. 460–c. 370 BCE) Democritus was a pre-Socratic philosopher, some say a disciple of Leucippus. Born in Abdera, Thrace. Everything consists of moving atoms. These are geometrically• indivisible and indestructible. Between lies empty space: the void. • Evidence for the void: Irreversible decay of things over a long time,• things get mixed up. (But other processes purify things!) “By convention hot, by convention cold, but in reality atoms and• void, and also in reality we know nothing, since the truth is at bottom.” Summary: everything is a dynamical system! • 4 Democritus-2 The earth is round (spherical). -
SOLAR ECLIPSE NEWSLETTER SOLAR ECLIPSE April 2002 NEWSLETTER
Volume 7, Issue 4 SOLAR ECLIPSE NEWSLETTER SOLAR ECLIPSE April 2002 NEWSLETTER SUBSCRIBING TO The sole Newsletter dedicated to Solar Eclipses THE SOLAR ECLIPSE MAILING Dear friends, Another issue has been compiled for you. LIST Time passes quickly. It’s April! Live is too THE SOLAR ECLIPSE MAIL- short… INGING LISTLIST ISIS MAINTAINEDMAINTAINED It has been busy on the SEML. Contribu- BY THE LIST OWNER PAT- tions of the subscribers have been good. RICK POITEVIN AND WITH The annular and the total for 2002 are well THE SUPPORT OF JAN VAN discussed, as well as both 2003 solar GESTEL eclipses. But many other topics as well of HOW TO SUBSCRIBE: course. ININ THETHE BODYBODY OFOF THETHE The SEML has been revised behind the MES SAGE TO screens. Many safeties have been built in. [email protected]@Aula.com SUSUB- All subscribers are in a data base. An up- SCRIBE SOLARECLIPSES dated and extended Welcome Question- name, country. naire has been send to all new subscribers, but as well to the current members. The replies are positive. We hope to get an idea The Solar Eclipse Mailing List of the background of all the SEML subscrib- family and we try to keep it friendly ers and know them a little better. It is a big and nice for everyone. The Solar Eclipse Mailing List (SEML) is an electronic newsgroup At the backpage of this issue, you will dedicated to Solar Eclipses. Pub- find a small part of the photographic lished by eclipse chaser Patrick collection of California 2002. Of Poitevin (patrick_poitevin@hotmail. -
Asteroids Upclose
Asteroids UpClose Quick Views of Big Advances Asteroids Up Close The importance of spacecraft missions in the quest to understand asteroids is highlighted in a recent review paper by Thomas Burbine (Mount Holyoke College, Massachusettes). Burbine discusses achievements in understanding the chemistries and mineralogies of asteroids since the launch of NASA's NEAR-Shoemaker robotic spacecraft in 1996, the first mission dedicated to asteroid exploration. As two new robotic asteroid-sample-return missions are underway (NASA's OSIRIS-REx and JAXA's Hayabusa2), Burbine's review paper and a review by Derek Sears earlier this year (see the January 2016 PSRD CosmoSparks: Comprehending Asteroids) provide timely recaps of why asteroids are so important to our understanding of the building Simulated cratering and topography are overlaid on blocks of our Solar System. radar imagery of asteroid Bennu — one of the next asteroids to be visited up close by NASA's OSIRIS- Burbine reviews these mission highlights: REx mission. Click image for more information from University of Arizona News. NEAR-Shoemaker (NASA mission) flew by (253) Mathilde, a C-complex asteroid. It orbited and landed on (433) Eros, an S-type asteroid, and used an X-ray spectrometer to determine elemental ratios, which were consistent with a body that did not melt globally. Most likely meteorite matches for Eros are surface-altered ordinary chondrites or primitive achondrites. For more see PSRD article: The Composition of Asteroid 433 Eros. Hayabusa (JAXA mission) was a touch-and-go mission to (25143) Itokawa, an S-complex asteroid. It carried a multiband imager, near-infrared spectrometer, laser altimeter, LIDAR, X-ray spectrometer, and a sample capsule. -
Final Report Asteroid Impact Monitoring
Final Report Asteroid Impact Monitoring Environmental and Instrumentation Requirements A component of the Asteroid Impact & Deflection Assessment (AIDA) Mission By the AIM Advisory Team Dr. Patrick MICHEL (Univ. Nice, CNRS, OCA), Team Leader Dr. Jens Biele (DLR) Dr. Marco Delbo (Univ. Nice, CNRS, OCA) Dr. Martin Jutzi (Univ. Bern) Pr. Guy Libourel (Univ. Nice, CNRS, OCA) Dr. Naomi Murdoch Dr. Stephen R. Schwartz (Univ. Nice, CNRS, OCA) Dr. Stephan Ulamec (DLR) Dr. Jean-Baptiste Vincent (MPS) April 12th, 2014 Introduction In this report, we describe the knowledge gain resulting from the implementation of either the European Space Agency’s Asteroid Impact Monitoring (AIM) as a stand- alone mission or AIM with its second component, the Double Asteroid Redirection Test (DART) mission under study by the Johns Hopkins Applied Physics Laboratory with support from members of NASA centers including Goddard Space Flight Center, Johnson Space Center, and the Jet Propulsion Laboratory. We then present our analysis of the required measurements addressing the goals of the AIM mission to the binary Near-Earth Asteroid (NEA) Didymos, and for two specified payloads. The first payload is a mini thermal infrared camera (called TP1) for short and medium range characterisation. The second payload is an active seismic experiment (called TP2). We then present the environmental parameters for the AIM mission. AIM is a rendezvous mission that focuses on the monitoring aspects i.e., the capability to determine in-situ the key properties of the secondary of a binary asteroid. DART consists primarily of an artificial projectile aims to demonstrate asteroid deflection. In the framework of the full AIDA concept, AIM will also give access to the detailed conditions of the DART impact and its outcome, allowing for the first time to get a complete picture of such an event, a better interpretation of the deflection measurement and a possibility to compare with numerical modeling predictions.