Yearbook of Astronomy 2021 BBooookk 11..iinnddbb 11 1155//0044//22002200 1177::2200 EDITED BY Front Cover: Launched in 2011 and arriving at Jupiter in 2016, NASA’s JUNO spacecraft is currently in a polar orbit that takes it out as far as 8 million kilometres before passing as close as 4,200 kilometres to Jupiter’s cloud tops. It is visualised here passing over Jupiter’s south pole. More information on the JUNO mission can be found in the articles Solar System Exploration in 2019 and Solar System Exploration in 2020 in the corresponding editions of the Yearbook of Astronomy. (NASA/JPL-Caltech) BBooookk 11..iinnddbb 22 1155//0044//22002200 1177::2200 EDITED BY BBooookk 11..iinnddbb 33 1155//0044//22002200 1177::2200 First published in Great Britain in 2020 by WHITE OWL An imprint of Pen & Sword Books Ltd Yorkshire – Philadelphia Copyright © Brian Jones, 2020 ISBN 978 1 52677 187 2 The right of Brian Jones to be identified as Author of this work has been asserted by him in accordance with the Copyright, Designs and Patents Act 1988. A CIP catalogue record for this book is available from the British Library. All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical including photocopying, recording or by any information storage and retrieval system, without permission from the Publisher in writing. Typeset in Dante By Mac Style Printed and bound by Printworks Global Ltd, London/Hong Kong Pen & Sword Books Ltd incorporates the Imprints of Pen & Sword Books Archaeology, Atlas, Aviation, Battleground, Discovery, Family History, History, Maritime, Military, Naval, Politics, Railways, Select, Transport, True Crime, Fiction, Frontline Books, Leo Cooper, Praetorian Press, Seaforth Publishing, Wharncliffe and White Owl. For a complete list of Pen & Sword titles please contact PEN & SWORD BOOKS LIMITED 47 Church Street, Barnsley, South Yorkshire, S70 2AS, England E-mail: [email protected] Website: www.pen-and-sword.co.uk or PEN AND SWORD BOOKS 1950 Lawrence Rd, Havertown, PA 19083, USA E-mail: [email protected] BBooookk 11..iinnddbb 44 1155//0044//22002200 1177::2200 Contents Editor’s Foreword 8 Preface 14 About Time 15 Using the Yearbook of Astronomy as an Observing Guide 17 The Monthly Star Charts Northern Hemisphere Star Charts David Harper 27 Southern Hemisphere Star Charts David Harper 53 The Planets in 2021 Lynne Marie Stockman 78 Phases of the Moon in 2021 81 Eclipses in 2021 82 Some Events in 2021 83 Monthly Sky Notes and Articles 2021 January 89 Astronomical Illustrations of the Nuremberg Chronicle Richard H. Sanderson 92 February 99 2I/Borisov – Interstellar Comet Neil Norman 101 March 107 Alfred Fowler Jane Callaghan 109 April 113 Salyut 1: The First Space Station Neil Haggath 116 May 119 Thomas Henry Espinell Compton Espin: The Double Star Curate of Tow Law John McCue 121 June 127 The Star That Was Older Than the Universe: The Mystery of HD 140283 David Harper 129 BBooookk 11..iinnddbb 55 1155//0044//22002200 1177::2200 6 Yearbook of Astronomy 2021 July 135 Early Precariously Balanced Refractors Gary Yule 137 August 143 Spare a Thought for the Engineers Rod Hine 145 September 149 Burying the Sun Carolyn Kennett 152 October 156 Tinkering With Time: The British Standard Time Experiment at 50 David Harper 158 November 163 Your Name in Space Peter Rea 165 December 171 Tycho Brahe Paul Fellows 174 Comets in 2021 Neil Norman 179 Minor Planets in 2021 Neil Norman 185 Meteor Showers in 2021 Neil Norman 191 Article Section Astronomy in 2020 Rod Hine 203 Solar System Exploration in 2020 Peter Rea 212 Anniversaries in 2021 Neil Haggath 223 Mission to Mars: Countdown to Building a Brave New World Martin Braddock 232 Male Family Mentors for Women in Astronomy: En’hedu’anna to Eimmart Mary McIntyre 240 Henrietta Swan Leavitt and Her Work David M. Harland 251 Solar Observing Peter Meadows 263 The Meteorite Age Carolyn Kennett 272 ‘A Dignity That Insures Their Perpetuation’ John C. Barentine 280 Lunar Volcanism: The View 50 Years after Apollo Lionel Wilson 291 Pages From the Past: Collecting Vintage Astronomy Books Richard H. Sanderson 300 The Chances of Anything Coming From Mars Jan Hardy 312 BBooookk 11..iinnddbb 66 1155//0044//22002200 1177::2200 Contents 7 Māori Astronomy in Aotearoa-New Zealand Pauline Harris, Hēmi Whaanga and Rangi Matamua 322 Miscellaneous Some Interesting Variable Stars Tracie Heywood 335 Some Interesting Double Stars Brian Jones 354 Some Interesting Nebulae, Star Clusters and Galaxies Brian Jones 357 Astronomical Organizations 359 Our Contributors 364 Glossary Brian Jones and David Harper 372 BBooookk 11..iinnddbb 77 1155//0044//22002200 1177::2200 Editor’s Foreword The Yearbook of Astronomy 2021 is the latest edition of what has long been an indispensable publication, the annual appearance of which has been eagerly anticipated by astronomers, both amateur and professional, for nearly sixty years. Approaching its Diamond Jubilee edition in 2022, the Yearbook of Astronomy is, as ever, aimed at both the armchair astronomer and the active backyard observer. Within its pages you will find a rich blend of information, star charts and guides to the night sky coupled with an interesting mixture of articles which collectively embrace a wide range of topics, ranging from the history of astronomy to the latest results of astronomical research; space exploration to observational astronomy; and our own celestial neighbourhood out to the farthest reaches of space. The Monthly Star Charts have been compiled by David Harper and show the night sky as seen throughout the year. Two sets of twelve charts have been provided, one set for observers in the Northern Hemisphere and one for those in the Southern Hemisphere. Between them, each pair of charts depicts the entire sky as two semi-circular half-sky views, one looking north and the other looking south. Lists of Phases of the Moon in 2021 and Eclipses in 2021 are also provided, together with general summaries of the observing conditions for each of the planets in The Planets in 2021, and a calendar of significant Solar System events occurring throughout the year in Some Events in 2021. The ongoing process of improving and updating what the Yearbook of Astronomy offers to its readers is continued in the 2021 edition with the introduction of apparition charts for Mars, Jupiter and Saturn. All the planetary apparition charts have been compiled by David Harper and the inclusion of the three listed here ensures that charts are now supplied for all the major planetary members of our Solar System. Further details of the planetary apparition charts are given in Using the Yearbook of Astronomy as an Observing Guide. As with The Planets in 2021 and Some Events in 2021, the Monthly Sky Notes have been compiled by Lynne Marie Stockman and give details of the positions and BBooookk 11..iinnddbb 88 1155//0044//22002200 1177::2200 Editor’s Foreword 9 visibility of the planets for each month throughout 2021. Each section of the Monthly Sky Notes is accompanied by a short article, the range of which includes items on a variety of astronomy-related topics such as Astronomical Illustrations of the Nuremberg Chronicle by Richard Sanderson, 2I/Borosov: Interstellar Comet by Neil Norman and Burying the Sun by Carolyn Kennett together with a trio of biographical articles relating to astrophysicist Alfred Fowler, double star observer Thomas Henry Espinell Compton Espin, and one of the best known astronomers of all time, Tycho Brahe. The Monthly Sky Notes and Articles section of the book concludes with a trio of articles penned by Neil Norman, these being Comets in 2021, Minor Planets in 2021 and Meteor Showers in 2021, all three titles being fairly self-explanatory describing as they do the occurrence and visibility of examples of these three classes of object during and throughout the year. In his article Astronomy in 2020 Rod Hine covers a range of topics, including taking a look at potential problems revealed by results gleaned from the Planck Observatory, which operated from 2009 to 2013 and which provided extensive data on Cosmic Microwave Background radiation. The problems that seem to have arisen for cosmologists relating to the amount of dark matter in the Universe are examined, and how this may (or may not) be resolved once the Simons Observatory in Chile begins operations in the early-2020s. This is followed by Solar System Exploration in 2020 in which Peter Rea covers a wide range of ongoing space missions. These include the collection and return to Earth of samples from the surfaces of two asteroids, one being 162173 Ryugu by the Japanese Hyabusa 2, and the other 101955 Bennu, which has been the target of the American OSIRIS-Rex. The ambitious goals of both these missions highlight the incredible advances that our exploration of other planetary members of the Solar System has made in recent years. In 2021 we celebrate the 450th anniversary of the birth of Johannes Kepler, best known for his three Laws of Planetary Motion published between 1609 and 1618. Neil Haggath discusses some of Kepler’s work in his article Anniversaries in 2021 as well as drawing to our attention the centenaries of the deaths of several other notable astronomers. These include the 350th anniversary of the death of Italian Jesuit astronomer Father Giovanni Battista Riccioli, who is credited for introducing the system of lunar nomenclature still in use today; the 150th anniversary of the death of Sir John Herschel, son of the great observer BBooookk 11..iinnddbb 99 1155//0044//22002200 1177::2200