DOCSLIB.ORG

The Dawn Discovery Mission: a Voyage in Space and Time

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Dawn Discovery Mission: a Voyage in Space and Time The Dawn Discovery Mission: A Voyage in Space and Time Christopher T. Russell Professor of Geophysics and Space Physics, UCLA Director of UCLA Branch, California Space Grant Consortium Principal Investigator of the Dawn Mission 2:20PM‐3:05PM, Sunday, October 13, 2013 Carolina Ballroom, Francis Marion Hotel National Council of Space Grant Directors’ Fall Meeting Charleston, South Carolina Solar System Formation Paradigm • Initially there was a nebula of cold gas and dust around a central condensation of gas that was to become the Sun. • Within this circulating nebula, solid bodies are forming. • Sometime in this process a supernova seeded the solar nebula with 26Al and 60Fe providing additional heat in bodies that were forming then. • Bodies that formed later and did not receive the “benefit” of the extra radioactive heat. • So there were rocky bodies formed, dried by their internal heat and wet bodies Trifid Nebula that stayed cool. 2 Asteroid Belt Evolution Paradigm • Vesta was clearly formed with trapped radionuclides that helped melt the rock and drive off the water. • Then Jupiter was formed and the main belt was stirred by its passage around the outer edge of the belt. This changed the asteroid belt from a region of growing protoplanets to one of colliding asteroid fragments. • Material from collisions were scattered toward the Earth falling as meteorites. These Early solar nebula by W. Hartmann have been used by scientists to understand the evolution of the solar system. 3 Primitive Meteorites Were Formed Earliest • The meteorites that have fallen to Earth were formed at different times and give us clues as to what happened in the early solar system. • Meteorites from Vesta tell us that it formed 1‐2 million years from the beginning of the solar system and it was rocky on the outside with an iron core. • This study is called cosmochemistry. • Mysteriously there are no meteorites from Ceres that we believe formed later. 4 Asteroid Belt Today • Today we see evidence of the stirring by Jupiter’s gravitational field by the Kirkwood gaps with orbital periods that are integral ratios of Jupiter’s orbital period. 5 Planetary Motions • In the 16th century, Tycho Brahe took careful orbital measurements of the planets. • Johannes Kepler used these positions to determine the planetary orbits and how the bodies moved about the Sun. • Kepler thought the gap between Mars and Jupiter was too large and wrote in 1596, “Between Mars and Jupiter I place a planet.” • Late in the 17th century, Isaac Newton used Kepler’s laws to deduce the universal law of gravitational. • 100 years later, Johann Titius added a footnote to a book he was translating that gave a mathematical progression for the positions of the planets from Mercury to Saturn with a gap between Mars and Jupiter. • Johann Bode saw the footnote and added the same text to his book without attribution. Eventually when this law predicted the location of Uranus, Bode confessed to his misdeed and the law became known as the Titius‐Bode’s law. 6 The Celestial Police • Baron Franz Xaver von Zach was intrigued by the Titius‐Bode law and searched the sky, but the region to be searched was too large. • So he formed an international group to help him search. • One of the observers was Giuseppe Piazzi, who on January 1, 1801, saw a dim star that was not on his star charts and it had moved by the next night. • Because of illness and bad weather, Piazzi lost Ceres and Carl Fredrick Gauss was called in to do the math. • On January 1, 1802, Baron Zach found Ceres again. Giuseppe Piazzi 7 Wilhelm Olbers • Later in 1802 on May 28, H.M. Wilhelm Olbers discovered 2 Pallas. This asteroid has a high orbital inclination and even if the Dawn spacecraft, concentrated solely on Pallas, it could not match orbits with this body. • On September 1, 1804, K. Harding discovered 3 Juno. • On March 29, 1807, Olbers became the first observer to discover 2 asteroids with the discovery of 4 Vesta. • No more asteroids were discovered for 38 years. • Eventually it was found that Ceres Statue of H.M.W. Olbers in Bremen and Vesta were the two most massive asteroids and were very, very different. 8 History of Dawn • 1992 – Discovery Workshop held. Dawn science team formed. • 1994 – Proposed Diana to Moon and active asteroid with TRW. Not selected. • 1996 – Proposed MBAR to Vesta, Lutetia, Glasenappia with CTA. Not selected. • 1998 – Proposed MBAR to Vesta, Lutetia with Orbital. Not selected. • 2000 – Proposed Dawn to Vesta, Ceres with Orbital. Selected for Step 1. 9 History of Dawn 2 Country Inn, Dulles, VA, Sept. 11, 2001 • 2001 ‐ Concept study begun. Step 2 proposal submitted in summer. Site visit scheduled for September 12 at Orbital. Canceled on 9/11. LA‐area Dawn team crosses country in 4 vehicles in 48 hours. Site visit rescheduled. Successful. Dawn selected with Kepler. 10 History of Dawn 3 • 2003 – Delayed because of funding. Need new rocket and launch date. Then have to descope laser altimeter. Cancelled on Christmas eve. • 2004 – January Orbital protests. Dawn reinstated. Mag lost. • 2004 –Dawn proceeds apace. • 2005 –Dawn asks for more funding and is stood down. • 2006 –In March, Dawn cancelled. JPL appeals and wins, and we finish building and testing the spacecraft. 11 History of Dawn 4 • 2007 –Orbital assembles, tests, and ships Dawn to the Cape for July launch. This is the second‐ to‐last opportunity before Ceres moves out of position. An afternoon launch in July is almost impossible. Boat and plane needed for mid‐Atlantic telemetry both have trouble. Fortunately, second stage does not get fueled or there would be no mission today. • Spacecraft does not get launched in June/July opportunity. • Spacecraft and third stage are disassembled and reassembled in September. Cape Canaveral Air Force Station 12 Dawn Launch: A Total Success! 13 September 27, 2007 Dawn Mission to Vesta and Ceres Vesta and Ceres are the two most massive objects in the main asteroid belt More meteorites found on the Earth come from Vesta than either the moon or Mars. Dawn will be the first spacecraft ever to: • Orbit a body in the main asteroid belt • Orbit two targets • Visit a dwarf planet 14 Rocket Science • If a spacecraft carries propellant, it is best • Dawn uses the most efficient possible ion to fire it at as high a speed as possible. engine. • If a spacecraft is lifting off a planet, it needs • It carries large solar panels so it has power a powerful engine. even far from the Sun. • If it is cruising for a long time in space, a • However, when electric power drops too weak efficient engine is very useful. much, our engine power and efficiency15 both drop. Dawn Mission Itinerary Vesta Ceres July 2011 –July 2012 Feb 2015 –July 2015 Mars Gravity Assist Feb 2009 At each target, Dawn will: Acquire color images Compile a topographic map Map the elemental composition Map the mineralogical composition Launch Measure the gravity field Sep 2007 Search for moons 16 Dawn’s Payload Framing Camera •Two redundant framing cameras (1024 x 1024 pixels, and 7 color filters plus clear) provided by VIR Germany (MPS and DLR) •A visible and infrared mapping spectrometer (UV to 5 microns) provided by Italy (INAF and ASI) •A Gamma Ray and Neutron Detector built by LANL and operated by PSI GRaND •A Radio Science Package provides gravity information • Topographic model derived from off‐nadir imaging 17 Orbit • Approach began with the first Optical Navigation images in early May. • Three rotation movies (RC = rotation characterization) were collected on approach. • Survey‐orbit science gathering began in early August; continued for a year. 18 Vesta Science Orbits • Dawn began taking data in a high Survey orbit. • It then used the ion propulsion system to transfer two times to lower orbits: – High Altitude Mapping Orbit (HAMO) – Low‐Altitude Mapping Orbit (LAMO) • Dawn then raised its orbit to perform a second HAMO, and departed from Vesta for Ceres in September 2012. 19 Earliest Movie Movie from Navigation Images 20 RC1 Movie 21 RC2 Movie 22 RC3 Movie 23 Vesta and its Siblings: Asteroids Visited to Date • Vesta seen here from above its south pole is the largest asteroid visited to date. •Previous orbital missions were to much smaller, near‐Earth asteroids, 433 Eros and 25143 Itokawa. •As begins to be seen in this image, Vesta is not just a chunk of rock but is a small planet with many of the geophysical processes we expect on a planet. 24 Vesta Bears the Scars of 4.65 Billion Years in Space •Vestahas a highly cratered surface but with regions of smooth plains, perhaps due to ejecta. •There are several different crater types: bright‐rayed, dark‐ rayed, no‐rays. •There are gouges, troughs, and scarps. •There are hills and valleys. 25 Equatorial Troughs • Equatorial troughs encircle the equator. •These appear to be associated with a giant impact near the south pole. •They may be rift valleys associated with compression and the relaxation. •The southern hemisphere may also be brighter. 26 The Ancient Basins • A large surprise was the second large ancient basin Veneneia. 27 The Interior of Vesta core crust mantle • The HEDs indicate that Vesta has an iron core, a mantle, and a crust. • We can measure the gravity moment J2 that is sensitive to the flattening of the core, and use the average density to constrain the silicate density. The vestan density is consistent with the HED data. 28 A Colorful Surface Reveals a Heterogeneous Body • This false color mosaic shows that much has gone on in Vesta’s interior.
Load more

Recommended publications
  • Discovery of the First Asteroid, Ceres Historical Studies in Asteroid Research Discovery of the First Asteroid, Ceres
    Cliff ord Cunningham Discovery of the First Asteroid, Ceres Historical Studies in Asteroid Research Discovery of the First Asteroid, Ceres Clifford Cunningham Discovery of the First Asteroid, Ceres Historical Studies in Asteroid Research Clifford Cunningham Ft. Lauderdale , FL , USA ISBN 978-3-319-21776-5 ISBN 978-3-319-21777-2 (eBook) DOI 10.1007/978-3-319-21777-2 Library of Congress Control Number: 2015950473 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2016 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfi lms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specifi c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Cover illustration: Ceres, picture taken February 19, 2015, by NASA’s Dawn spacecraft, from a distance of nearly 29,000 miles (46,000 km).
    [Show full text]
  • Radio Science Bulletin Staff
    INTERNATIONAL UNION UNION OF RADIO-SCIENTIFIQUE RADIO SCIENCE INTERNATIONALE ISSN 1024-4530 Bulletin No 355 December 2015 Radio Science URSI, c/o Ghent University (INTEC) St.-Pietersnieuwstraat 41, B-9000 Gent (Belgium) Contents Radio Science Bulletin Staff .......................................................................................3 URSI Offi cers and Secretariat ................................................................................... 6 Editor’s Comments ..................................................................................................... 8 URSI AP-RASC 2016 ................................................................................................10 Introduction to Special Section on Disaster Management .................................... 11 Some Thoughts on Disaster Management .............................................................. 13 DEMETER Results Related to Seismic Activity .................................................... 18 Topology Control of a Network of Autonomous Aerial Drones ............................26 Designing Autonomous Crawling Equipment to Detect Personal Connected Devices and Support Rescue Operations: Technical and Societal Concerns .. 35 Calibration Procedures for Global Precipitation-Measurement Ground-Validation Radars ...................................................................................45 Et Cetera ....................................................................................................................74 Early Career Representative
    [Show full text]
  • From William Hyde Wollaston to Alexander Von Humboldt
    This article was downloaded by: [Deutsches Museum] On: 15 February 2013, At: 08:42 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Annals of Science Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tasc20 From William Hyde Wollaston to Alexander von Humboldt - Star Spectra and Celestial Landscape Jürgen Teichmann a & Arthur Stinner b a Deutsches Museum and Ludwig-Maximilians-University, München, Germany b University of Manitoba, Winnipeg, Canada Version of record first published: 13 Feb 2013. To cite this article: Jürgen Teichmann & Arthur Stinner (2013): From William Hyde Wollaston to Alexander von Humboldt - Star Spectra and Celestial Landscape, Annals of Science, DOI:10.1080/00033790.2012.739709 To link to this article: http://dx.doi.org/10.1080/00033790.2012.739709 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.tandfonline.com/page/terms-and- conditions This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.
    [Show full text]
  • Historical & Cultural Astronomy
    Historical & Cultural Astronomy Historical & Cultural Astronomy EDITORIAL BOARD JAMES EVANS, University of Puget Sound, USA MILLER GOSS, National Radio Astronomy Observatory, USA JAMES LEQUEUX, Observatoire de Paris, France SIMON MITTON, St. Edmund’s College Cambridge University, UK WAYNE ORCHISTON, National Astronomical Research Institute of Thailand, Thailand MARC ROTHENBERG, AAS Historical Astronomy Division Chair, USA VIRGINIA TRIMBLE, University of California Irvine, USA XIAOCHUN SUN, Institute of History of Natural Science, China GUDRUN WOLFSCHMIDT, Institute for History of Science and Technology, Germany More information about this series at http://www.springer.com/series/15156 Clifford J. Cunningham Editor The Scientific Legacy of William Herschel Editor Clifford J. Cunningham Austin, Texas, USA ISSN 2509-310X ISSN 2509-3118 (electronic) Historical & Cultural Astronomy ISBN 978-3-319-32825-6 ISBN 978-3-319-32826-3 (eBook) https://doi.org/10.1007/978-3-319-32826-3 Library of Congress Control Number: 2017952742 © Springer International Publishing Switzerland 2018 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
    [Show full text]
  • I the Wahhabis Seen Through European Eyes (1772–1830)
    i The Wahhabis Seen through European Eyes (1772–1830) © koninklijke brill nv, leiden, 2015 | doi 10.1163/9789004276338_001 ii The History of Oriental Studies Editors Alastair Hamilton (University of London) Jan Loop (University of Kent) Thomas Burman (University of Tennessee) Advisory Board Charles Burnett (London) – Bernard Heyberger (Paris) Noel Malcolm (Oxford) – Jan Schmidt (Leiden) Francis Richard (Paris) – Arnoud Vrolijk (Leiden) Joanna Weinberg (Oxford) VOLUME 1 The titles published in this series are listed at brill.com/hos iii The Wahhabis Seen through European Eyes (1772–1830) Deists and Puritans of Islam By Giovanni Bonacina LEIDEN | BOSTON iv Originally published as Eretici e riformatori d’Arabia. I wahhâbiti in prospettiva europea 1772-1830. ©2011 by Edizioni Scientifiche Italiane s.p.a. Cover illustration: Ibrahim Pasha fighting the Wahhabis, Arabia, 1816–1818. Artist: Jean Adolphe Beaucé (from: E. Gouin, L’Égypte au XIXe siècle, Boizard, Paris, 1847, p. 296). Library of Congress Cataloging-in-Publication Data Bonacina, Giovanni, 1961- [Eretici e riformatori d’Arabia. English] The Wahhabis seen through European eyes (1772-1830) : deists and Puritans of Islam / by Giovanni Bonacina. pages cm. -- (The history of Oriental studies, ISSN 2405-4488 ; volume 1) Includes bibliographical references and index. ISBN 978-90-04-29301-4 (hardback : acid-free paper) -- ISBN 978-90-04-29328-1 (e-book) 1. Wahhabiyah-- Public opinion--History. 2. Public opinion--Europe--History--18th century. 3. Public opinion--Europe-- History--19th century. 4. Europe--Intellectual life--18th century. 5. Europe--Intellectual life--19th century. I. Title. BP195.W2B6613 2015 297.8’14--dc23 2015003500 This publication has been typeset in the multilingual “Brill” typeface.
    [Show full text]
  • HEGEL and the SEVEN PLANETS EDWARD CRAIG and MICHAEL
    JHA, xxiii (1992) NOTE HEGEL AND THE SEVEN PLANETS EDWARD CRAIG and MICHAEL HOSKIN, Churchill College, Cambridge In the Copernican system, Earth-based observers were able to derive the radii of the planetary orbits in terms of the (mean) Earth-Sun distance, from obser­ vation and elementary trigonometry. Before the end of the sixteenth century, Kepler had been struck by the disproportionate gap between the orbits of the fourth planet, Mars, and the fifth, Jupiter, and had considered the possibility of filling the gap with a planet hitherto unobserved.' Although Kepler eventually found an alternative way of dealing with this apparent anomaly in the planetary system, other astronomers continued to feel uncomfortable with the system as presently understood, and the formulation in the last quarter of the eighteenth century of the arithmetical relation known as 'Bode's Law' served to bring matters to a head.' In this Law, the distances from the Sun of the six known planets were seen as roughly proportional to the numbers 4, 4 + 3, 4 + 2.3, 4 + 4.3, 4 + 16.3 and 4 + 32.3, but no known planet corresponded to the term 4+8.3. The Law received unexpected support from the discovery by William Herschel in 1781 of the planet Uranus, whose solar distance corresponded well with the next term in the arithmetical sequence, 4 + 64.3; and at the close of the century Franz Xaver von Zach and others joined forces to organize a systematic search- for the supposed missing planet between Mars and Jupiter correspond­ ing to the term 4 +8.3.
    [Show full text]
  • Giuseppe Piazzi and the Discovery of Ceres
    Foderà Serio et al.: The Discovery of Ceres 17 Giuseppe Piazzi and the Discovery of Ceres G. Foderà Serio Universita’ di Palermo A. Manara Osservatorio Astronomico di Brera P. Sicoli Osservatorio Astronomico di Sormano In this chapter we focus on the circumstances that led Giuseppe Piazzi (1746–1826) to dis- cover the first asteroid, Ceres, on January 1, 1801. Through the examination of published and archival documentation, we shed light on the reaction of the astronomical community at the announcement of the discovery and on Piazzi’s puzzling behavior. In the end, we briefly discuss the discoveries of Pallas, Juno, and Vesta and the theories put forward to explain their nature. 1. INTRODUCTION scope made by Jesse Ramsden of London (Piazzi, 1792; Pearson, 1829; Chinnici et al., 2001). Returning to Palermo Gioacchino Giuseppe Maria Ubaldo Nicolò Piazzi was in November 1789, Piazzi was able, in a matter of months, born in Ponte, Valtellina, July 16, 1746, to one of the wealth- to have the new observatory built on top of the tower of iest families of the region. The penultimate of 10 sons, most Santa Ninfa at the Royal Palace. of whom died as children, his parents worried about his health and for this reason quickly baptized him at home. The register of baptisms of St. Maurizio Church clearly spec- ifies “ob imminens vitae periculum,” or “because of impend- ing danger of death” (Maineri, 1871; Invernizzi et al., 2001). Following the tradition that encouraged younger children of wealthy and noble families to take holy orders, Giuseppe joined the Teatine order at the age of 19.
    [Show full text]
  • And the Ends of Jesuit Science in Enlightenment Europe
    Maximilian Hell (1720–92) and the Ends of Jesuit Science in Enlightenment Europe <UN> Jesuit Studies Modernity through the Prism of Jesuit History Editor Robert A. Maryks (Independent Scholar) Editorial Board James Bernauer, S.J. (Boston College) Louis Caruana, S.J. (Pontificia Università Gregoriana, Rome) Emanuele Colombo (DePaul University) Paul Grendler (University of Toronto, emeritus) Yasmin Haskell (University of Western Australia) Ronnie Po-chia Hsia (Pennsylvania State University) Thomas M. McCoog, S.J. (Loyola University Maryland) Mia Mochizuki (Independent Scholar) Sabina Pavone (Università degli Studi di Macerata) Moshe Sluhovsky (The Hebrew University of Jerusalem) Jeffrey Chipps Smith (The University of Texas at Austin) volume 27 The titles published in this series are listed at brill.com/js <UN> Maximilian Hell (1720–92) and the Ends of Jesuit Science in Enlightenment Europe By Per Pippin Aspaas László Kontler leiden | boston <UN> This is an open access title distributed under the terms of the CC-BY-NC-Nd 4.0 License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The publication of this book in Open Access has been made possible with the support of the Central European University and the publication fund of UiT The Arctic University of Norway. Cover illustration: Silhouette of Maximilian Hell by unknown artist, probably dating from the early 1780s. (In a letter to Johann III Bernoulli in Berlin, dated Vienna March 25, 1780, Hell states that he is trying to have his silhouette made by “a person who is proficient in this.” The silhouette reproduced here is probably the outcome.) © Österreichische Nationalbibliothek.
    [Show full text]
  • Enlightened and Jesuit Networks, and a New Node of Science
    Chapter 2 Metropolitan Lures: Enlightened and Jesuit Networks, and a New Node of Science 1 An Agenda for Astronomic Advance In January 1755, the Viennese court mathematician Johann Jakob (Giovanni Jacopo) Marinoni (1676–1755) passed away. Originally from Udine, Marinoni, whose contribution to the beginnings of astronomical observation activities in the Habsburg capital has already been mentioned briefly,1 was appointed in 1703, and from 1720 he also served as the second director of the Viennese Impe- rial and Royal Academy for Engineering (Wiener kaiserliche und königliche Ingenieurakademie), established in 1717 under the auspices of the Aulic War Council primarily to ensure the adequate training of military engineers.2 Dur- ing his more than five-decade career in Vienna, Marinoni also played leading roles in large-scale government-run projects, from modernizing and expand- ing the system of fortifications around the capital to the land survey of Lom- bardy (the so-called “Theresan cadaster”—in fact begun long before Maria Theresa’s accession).3 As a surveyor, he introduced new methods and instru- ments in the Habsburg lands; as an astronomer, he carried out observations (also popularized in broadsheets) and even assembled students to instruct in the small observatory in his home in central Vienna, equipped with instru- ments purchased from far and wide, and donated in his last will to the court. In 1745, Marinoni published a volume describing the observatory, its activities, and equipment in great detail. The book was dedicated to the empress, and recommended by its reviewers, Frölich and Franz, as a textbook.4 This was a formidable legacy in more sense than one.
    [Show full text]
  • This Thesis Has Been Submitted in Fulfilment of the Requirements for a Postgraduate Degree (E.G
    This thesis has been submitted in fulfilment of the requirements for a postgraduate degree (e.g. PhD, MPhil, DClinPsychol) at the University of Edinburgh. Please note the following terms and conditions of use: • This work is protected by copyright and other intellectual property rights, which are retained by the thesis author, unless otherwise stated. • A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. • This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the author. • The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author. • When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given. Geography and Enlightenment in the German states, c.1690 – c.1815 Luise Fischer Doctor of Philosophy The University of Edinburgh 2014 Abstract This thesis is concerned with the science of geography in the German states during the ‘long’ eighteenth century, c.1690 – c.1815. It speaks to recent scholarly debates in historical geography, the history of science, book history, and Enlightenment studies. The thesis investigates the forms taken by eighteenth-century German geography, its meanings, and practices. This is of particular interest, since this topic is understudied. The thesis is based upon an analysis of geographical print (books and periodicals) and manuscript correspondence. The thesis proposes that geography’s definition was understood as ‘description of the earth’. The interpretative meaning of this definition, geography’s purpose in print, and its educational practice (content and methods) were, in contrast, debated.
    [Show full text]
  • Victoria Centre
    ROYAL ASTRONOMICAL SOCIETY OF CANADA: VICTORIA CENTRE Monkey Head Nebula, by Joe Carr Arizona 2019 - Stars over the High Desert! Oh, what a difference 17 degrees of latitude make - AND - a whole lot of darkness in those starry Arizona skies.... In early March, a group of us joined Garry Sedun at his ranch home near the Dragoon Mountains, southeast of Tucson, for a week of stargazing and imaging. Chris and Christine Purse left Victoria a few days earlier, so they could enjoy touring the Phoenix and Tucson areas, including Kitt Peak Observatory. Joe Carr, John McDonald, Lauri Roche, and I flew into Phoenix on March 2nd, and from there enjoyed a road trip southeast to the ranch, before meeting up with the rest of the community. SKYNEWS April 2019 ISSUE #407 Page 1 ROYAL ASTRONOMICAL SOCIETY OF CANADA: VICTORIA CENTRE Rainbow over the Dragoon Range, by Diane Bell We came packed with our wish lists, log books, cameras, and computers. It was a good opportunity for Lauri and Chris to work on their “Explore the Universe” projects; moving closer to completing their certificate work. I came with my own logbook, star maps, an exhaustive list of NGC objects, my trusty 25x100 binoculars, and some telescope covers I made for Garry’s 20” and 25” Newtonians. The night skies were glorious. Although there were small, light domes low on the horizon, from the nearby towns and cities, they didn’t hamper the darkness above. The stars were amazing. The crazy tilt of the constellations, at 32 degrees north, was evident. We were reacquainted with some old acquaintances, including Canopus, the second brightest star in the night sky.
    [Show full text]
  • Description of the Ramsden Circle (Fig. A.1)
    Appendix A Description of the Ramsden Circle (Fig. A.1 ) A Description of the Ramsden Circle used by Piazzi to discover Ceres, as written by Pearson ( 1829 ). 1 . The fi rst astronomical circular instrument that was made by Ramsden , was that with which the late eminent astronomer, Piazzi of Palermo, took those series of observa- tions, from which the declinations in his much esteemed catalogue were computed and published, fi rst in 1803, and then in an improved state in 1814. Piazzi informs us, that Ramsden twice undertook the construction of this instrument, and as often abandoned it; but at length in January of the year 1788, he entered upon the work in earnest, and fi nished it in August 1789. 2 . The vertical axis of the instrument is composed of various parts, which, being fi rmly united together, constitute a frame that revolves in one piece on two pivots at the extreme ends; the cone, that terminates the lower extremity, tapers from a diameter of 14.2 inches to 5, where it is made fast to the horizontal circle, on which the azimuthal angles are measured, of three feet diameter. This circle has ten tubular radii of a coni- cal form, and is divided into two semicircles, fi gured into 180 degrees, each of which is subdivided into spaces of 6’; it revolves with the frame composing the vertical axis. The base of the inverted cone is fi rmly attached to an oblong plate of metal, which may be called the lower stage, and into which four long vertical tubes are fastened, as so many pillars, to support the upper stage, of the same dimensions as the lower one, namely 25.3 by 16.8 inches.
    [Show full text]