The Board of Dlrec:tolll The naming of comets can, indeed, be a very difficult matter. Traditionally these small, CARL SAGAN BRUCE MURRAY President Vice President icy solar system bodies were named for their discoverers. But because some people are Director" Laboratory Professor of Planetary very persistent (for example, there are four Comets Meier) a particular name is needed for Planetary Studies. Science, California Camell University Institute of Technology for each individu.al comet. Thus, at discovery a comet is assigned a letter designation LOUIS FRIEDMAN HENRY TANNER based on the order of discovery or recovery in a certain year. So, Comet 1982i was the Executive Director Corporate Secretary and 9th comet found in 1982. Later, comets are assigned new names based on their peri­ Assistant Treasurer, Cafifom;a THOMAS O. PAINE Institute of Technology helion (closest approach to the Sun). 1984 XXll1 was the 23rd comet to pass perihelion Former Administrator. NASA: Chairman, National JOSEPH RYAN in 1984. Confused? Here is a poetic attempt to explain. Commission on Space O'Melveny & Myers Board of Advlsolll DIANE ACKERMAN GARRY E. HUNT poet and author Space -Scientist, THE NAMING OF COMETS (With apologies to T. S. Eliot) United Kingdom ISAAC ASIMOV aulhor HANS MARK BY DAVID H. LEW Chancellor, RICHARD BERENDZEN University of Texas System Presid8nt, American University JAMES MICHENER The naming of Comets is a difficult matter, JACQUES BLAMONT author Chief Scien#st, Centre National It isn't just one of your holiday games; d'Etudes Spatlales, France PHILIP MORRISON Institute Professor, You may think at first I'm mad as a hatter RAY BRADBURY Massachusetts poet and author Institute of Technofogy When I tell you, a comet has THREE DIFFERENT NAMES. ARTHUR C. CLARKE PAUL NEWMAN First of all, there's the name that the family use daily, author actor Such as Whipple, Wilk-Peltier, Wirtanen or Woif, CORNELIS DE JAGER BERNARD M. OLIVER Such as Hubble or Humason, Honda, PlHalley- Professor of Space Research, Chief, SETI Program, The Astronomical Institute at NASA/Ames Research Center All of them sensible everyday names, Utrecht, The Netherlands There are fancier names if you think they sound sweeter, FRANK DRAKE SALLY RIDE Dean. Division of Natural astronaut Some for the gentlemen, some for the dames: Sciences. University of ROALD Z. SAGDEEV Such as Grigg-Skjellerup, de Kock-Paraskevopoulos, Celilornia at Santa Cruz Director. Institute for Cosmic Research, Academy Schwassmann-Wachmann, Herschel-Rigollet, Tsuchinshan 1, LEE A DUBRIDGE of Sciences of the USSR former presidential Churyumov-Solodovnikov, Bappu-Bok-Newkirk- science advisor HARRISON H. SCHMITT former US Senator, NM, But all of them sensible everyday names. JOHN GARDNER and former astronaut founder, Common Cause But I tell you, a comet needs a name that's particular, LEWIS THOMAS THEODORE M. HESBURGH Chancelfor, Memorial Sloan A name that's peculiar, and more dignified, President. K.effering Cancer Center UniverSity of Notre Dame Else how can he keep up his tail antisolar, JAMES VAN ALLEN SHIRLEY M, HUFSTEDLER Professor of Physics, Or spread out emissions, or cherish his pride? educator and jurist University of Iowa Of names of this kind, I can give you a score. The Plenetary Report (ISSN 0736-3680) Is published six 191Oa, '84u, '86b, and such, times yearly at the editorial offices of The Planetary Society, 65 North Catalina Ave., Pasadena, CA 91 106 Or '6Sf, '66b, '83d - there's more- Editor, CHARLENE M. ANDERSON; Names that never belong to more than one comet. Technical Editor, JAMES D. BURKE; Guest Technical Editor, JURGEN' RAHE; But above and beyond there's still one name left over, Associate Editor, LYNDINE McAFEE; And that is the name that at first you can't guess; Assistant Editor, DONNA STEVENS; The name that no human research can discover­ Art Director, BARBARA SMITH Until long after the comet's come and it's gone, Viewpoints expressed in columns or editorials are those of the authors and do not necessarily represent positions of The Planetary Like Nineteen hundred fifty-nine-X- Society, its officers or advisors. C> 1987 by The Planetary Society. In Canada. Second Class Mall Registration NLmber 9597 But the COMET HIMSELF KNOWS, and won't now confess. When you notice a comet in profound meditation, COVER: With Images like thl. one, scientists wete The reason, I tell you, is always the same: at last able to tBlre a close look at the nucleus of Halley's Comet. Here sunlight Is coming from the His mind is engaged in rapt contemplation left, hestJng the Icy body so thst dust IItId gss jets Of the thought, of the thought, of the thought of his name; erupt from Its surface. NeIIr the top are bright spots, His rotational, orbital and below them Is a crater-like festure about 1.5 IcJlometers In dl.meter. This could be a slump feB. Coma-morphological, ture formed by the outgaSSing of nesmy Jets. Below Deep and inscrutable singular Name, and right of the "creter H Is a bright festure about ? . 400 meters high that some scientists call "the David Levy is a member of the International Halley Watch Near Nucleus-iStudies Network mountsln. H I",. t8ken by /he HIIlley Multlcolor CarnenI © 1986 Max Planck InstIIut filr A.ronomle, UndllfllHttrz, in Tucson, Arizona. In January he discovered his second comet, Levy I987A, whose name, F.R.G., provided by H,J. ReItsem/J ttnd w,A. Del.",.,.., B.IIA~ unfortunately, did not fit into the meter of this poem, ·. .. .. .. .. .. .. .. .. .. .. .. Studying Halley's . ) • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • fr"m Earth and from Space • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • ~ • • • • • • • • • • • • • • • • t BY JURGEN RAHE OR CENIURlES, COMETS HAVE BEEN and international science groups endorsed France, Germany and North America, and studied by scientists living and the IHW, the American and West German used these measurements to prove that Fworking in many different countries space agencies agreed to fund it and two comets move in orbits around the Sun and and cooperation has been an essential Lead Centers were established, the Western that they are independent members of the part of their science. Because comets ap­ Hemisphere Office in Pasadena, California solar system. pear only briefly in our sky and because and the Eastern Hemisphere Office in In 1835 F. W. Bessel's extensive observa­ Earth never stops turning, no one scientist Bamberg, Federal Republic of Germany. tions of Halley's Comet clearly showed or observatory can hope to make compre­ The International Halley Watch follows that single observations provided only a hensive observations of any comet. And a long tradition of cooperation across na­ snapshot of the comet and that, for most not all places on Earth are equally good tional boundaries, beginning in the 16th studies, obseJVing sequences were needed. for watching a comet. In the case of Hal­ century. At that time, scientists generally Realizing this, the Astronomical and Astro­ ley's Comet, as it nears the Sun and glows accepted Aristotle's idea that comets were physical Society of America (now the Amer­ its brightest, it swings "south" of Earth, poisonous vapors in Earth's atmosphere. ican Astronomical Society) in 1909 created below the ecliptic (the plane defined by Then, in 1577, Tycho Brahe combined a special Comet Committee to prepare a the planets' orbits) and so appears highest careful position measurements he had photographic history of Halley's Comet: in the southern skies. But on its way in made from his observatory on the island "The ends to be served by these photo­ and out of the inner solar system, it of Hven near Copenhagen with those ob­ graphs and similar ones obtained else­ crosses the ecliptic, and so is best seen tained by Hagecius in Prague. With these where are conceived by the Committee as from the northern hemisphere. widely spaced measurements, he deter­ follows: to give a permanent record, as So, if scientists were to obtain the best mined that the comet displayed a very continuous as possible, of the phenomena possible coverage of Halley's Comet during small parallax. (That is, its position against and changes (0 in the tail of the comet, its 1985-86 apparition, we would have to the star background differed only slightly with special reference to outgoing masses; organize and set up a network of observ­ in the two observations.) He concluded (i0 in the head and nucleus of the comet, atories and observers distributed as un­ that the comet had to be at least 240 Earth particularly as to the formation of envelopes iformly as possible around the world. And radii away - four times farther from Earth and jets." since several countries were planning to than the Moon, and so well beyond the The committee had much in its favor­ send spacecraft to meet the comet, their atmosphere. thorough organization and well-defined observations should be coordinated with By combining observations made in dif­ goals - but it lacked several important in­ those from Earth. ferent countries, Brahe clearly demonstrated gredients: Although it needed and wanted In 1979, Louis D. Friedman, then at that comets move in interplanetary space cooperation from observatories all over the NASA's Jet Propulsion Laboratory and now beyond Earth's orbit. While he did not de­ world, it did not have international mem­ Executive Director of The Planetary Soci­ scribe correctly the orbits of the planets and bership; in addition, it did not have the ety, proposed a worldwide organization of the comet, his measurements profoundly cooperation of participating observatories professional and amateur astronomers, changed the scientific view of comets. in forwarding the material obtained to the called the International Halley Watch About a century later, in 1687, Isaac committee. Nor did it have adequate fund­ OHW), to coordinate observations of the Newton described the motion of a comet ing and staffing to follow up the scientific comet over the entire apparition.