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The Comet's Tale THE COMET’S TALE Newsletter of the Comet Section of the British Astronomical Association Volume 12, No 2 (Issue 24), 2005 October Deep Impact hit by 9P/Tempel was possibly a comet or carbonaceous chondrite, but there is probably a gradation between these bodies anyway. The outer Oort Cloud goes half way to alpha Centauri in all directions, but the inner cloud is more in the plane of the solar system. Dynamics move objects both inwards and outwards. Stardust used an aerogel to capture material; this is a glass with a density of only 3 mgcm-3. The material returned by Stardust will loose its ices. The DI impactor was made from copper, as this was cheaper than gold or silver. The impactor was actually hollowed out to reduce the bulk density so as to increase impact efficiency. The duration of the Stardust mission is much longer than DI – 6 years compared to 6 months. The July 4 impact date was fixed by a combination of the perihelion date and ecliptic crossing both of which occurred a few days later, and the publicity requirements. Comet 19P/Borrelly (imaged by Deep Space 1) was an odd shape, but 9P was quite different. 81P had huge The Deep Impact (DI) mission Both spacecraft are part of the features with near vertical walls. has returned spectacular images of Discovery programme – small, 9P/Tempel, although visually it cheap missions costing less than was not the event of the year. 300 M$. Stardust is the first Contents Mike A’Hearn gave us details of sample return mission since Comet Section contacts 2 the latest scientific results from Apollo 17, whilst Deep Impact Section news 2 this and the Stardust missions at was the first impact mission since Tales from the past 3 the BAA out of London meeting Apollo. Both are to Jupiter Deep Impact (cont) 4 in Cambridge, which was held Family Comets, but 81P/Wild (the Professional tales 4 just before the American Stardust target) has had its Prospects for 2006 6 Astronomical Society Division for perihelion changed recently. Review of observations 10 Planetary Sciences Meeting. Comets may have brought water Meeting review 17 and organics to Earth. The KT event that finished the dinosaurs BAA COMET SECTION NEWSLETTER 2 THE COMET'S TALE Comet Section contacts Director: Jonathan Shanklin, 11 City Road, CAMBRIDGE. CB1 1DP, England. Phone: (+44) (0)1223 571250 (H) or (+44) (0)1223 221482 (W) Fax: (+44) (0)1223 221279 (W) or (+44) (0) 1223 571250 (H) E-Mail: [email protected] or [email protected] WWW page : http://www.ast.cam.ac.uk/~jds/ Assistant Director (Observations): Guy Hurst, 16 Westminster Close, Kempshott Rise, BASINGSTOKE, Hampshire. (and also Editor of RG22 4PP, England. The Astronomer magazine) Phone & Fax: (+44) (0)1256 471074 E-Mail: [email protected] or [email protected] Assistant Director (CCD): Nick James, 11 Tavistock Road, CHELMSFORD, Essex. CM1 5JL, England. Phone: (+44) (0)1245 354366 E-mail: [email protected] Photographic Advisor: Michael Hendrie, Overbury, 33 Lexden Road, West Bergholt, COLCHESTER, Essex, CO6 3BX, England Phone: (+44) (0)1206 240021 The Section newsletter is now free to all BAA Members who make contributions to the work of the Section. The cost for other postal subscribers is £5 for two years, extended to three years for those who contribute to the work of the Section in any way, for example by submitting observations or articles. Renewals should be sent to the Director and cheques made payable to the BAA. Those due to renew should receive a reminder with this mailing. You can also download the newsletter (in colour) from the Section web page. Section News from the Director Dear Section member, You will notice that I’ve bound of London meeting, which was the observing supplement with the held in Cambridge prior to the Yet again it has been a busy six main issue. This is largely to DPS meeting, and some months for me, particularly at make life easier for me when I highlights from the DPS meeting work, where I have been involved have to put the issue in the itself. in the design of the science envelope, and unless there are quarters on the new Antarctic strong objections, I plan to go You can now pay subscriptions to station that we are planning at further next time, and include the the ICQ, IAUC, MPEC etc by Halley. Facilities include an ephemerides, finder charts and credit card via the cfa secure web optical caboose, which is visibility diagrams with the site at http://cfa- primarily for atmospheric review of observations. www.harvard.edu/iau/services/On observation of the aurora and LineOrders.html. The new skyglow, but has in the process Deep impact had a very printed Catalogue of Cometary imaged comets and meteors. We successful collision with comet Orbits 2005 costs $40 via surface don’t have any research 9P/Tempel. New results from the mail and the printed ICQ is $50 programmes in astronomy, but do studies continue to trickle in and per year by airmail. It is also have a Meade ETX125 for leisure are regularly published in the possible to subscribe to the BAA use. It has proved difficult to use astronomical journals. One and purchase BAA sales items via on our present science platform, concern that I have is the the internet from the BAA web as it sways too much (only conservatism of many groups of page at http://www.britastro.org minutes of arc) for steady astronomers. One example is the viewing. My other leisure large number of professionals I would like to thank BAA interests include natural history, who use the incorrect members: James Abbott, Peter particularly botany, but with the nomenclature and append 1 after Birtwhistle, Roger Dymock, John advance of autumn and the Tempel. Elsewhere they use CG Fletcher, Massimo Giuntoli, change of clocks there is less as an abbreviation for the Rosetta Werner Hasubick, Guy Hurst, suitable time for these. It is target, when 67P would suffice. I Nick James, Geoffrey Johnstone, perhaps fortunate that it has been try and use the CBAT Albert Jones, Richard Miles, a quiet autumn so far for comet nomenclature throughout the Martin Mobberley, Gabriel Oksa, observing, so I have at last had Comet Section reports. Another Roy Panther, Jonathan Shanklin, time to start putting this issue of example is those who try and Jeremy Shears, Giovanni Sostero, the newsletter together, albeit maintain that Pluto is still a major David Strange, Cliff Turk, Alex over a month later than the normal planet, when clearly it is just a Vincent, and also: Jose Aguiar, schedule. Kuiper Belt Object. In this issue Alexandre Amorim, Alexander there are reports of the talk given Baransky, Nicolas Biver, Reinder by Mike A’Hearn at the BAA Out Bouma, Jose Carvajal, Edwin van BAA COMET SECTION NEWSLETTER 2005 OCTOBER 3 Dijk, Stephen Getliffe, Vergil comprehensive light curves that N1 (Juels-Holvorcem), 2005 P3 Gonano, JJ Gonzalez, Bjorn appear in each issue of The (SWAN), 2005 R2 (P/Van Ness) Granslo, Ernesto Guido, Michael Comet’s Tale. Observations from and 2005 T4 (SWAN). Jager, Andreas Kammerer, Heinz groups that currently do not send Kerner, Mark Kidger, Carlos observations to the BAA would I hope to produce the April issue Labordena, Martin Lehky, A be much appreciated as they make on schedule, although I will be Lepardo, Rolando Ligustri, a valuable addition to the visiting the Antarctic again, from Michael Mattiazzo, Sensi Pastor, analyses. roughly mid February until Maciej Reszelski, Jose Reyes, towards the end of March. In Juan San Juan, Pepe Manteca, Comets under observation theory I should be in e-mail Jose Martinez, Andrew Pearce, included: 9P/Tempel, contact during this period, as a Stuart Rae, Walter Robledo, V 21P/Giacobini-Zinner, new permanent satellite link is Santini, Tony Scarmato, Tony 29P/Schwassmann-Wachmann, being installed at the station that Ward and Seiichi Yoshida 37P/Forbes, 62P/Tsuchinshan, I’m visiting. I’m not expecting (apologies for any errors or 117P/Helin-Roman-Alu, too much in the way of clear omissions) for submitting 161P/Hartley-IRAS, 169P/NEAT, skies, as the station is at the west observations or contributions 2003 T4 (LINEAR), 2005 A1 end of South Georgia, and is since the last newsletter. Without (LINEAR), 2005 E2 (McNaught), notoriously cloudy. these contributions it would be 2005 JQ5 (P/Catalina), 2005 K1 impossible to produce the (Skiff), 2005 K2 (LINEAR), 2005 Jonathan Shanklin Tales from the Past This section gives a few excerpts 1882 R1, the inclination is 1930 BC to AD 1986” and the from past RAS Monthly Notices prograde, ruling this out. other entitled “The Comet of and BAA Journals. Surprisingly Kronk makes no David and Halley’s Comet”. He reference to Dorfel’s observations attempts to reconcile a return in 150 Years Ago: Nothing of or his orbit computation. A note 1005.34 BC with the construction interest! from AN No 4025 notes of the Temple of Jerusalem in 989 measurements of what was clearly BC. Comet Notes records the 100 Years Ago: At the April a disconnection event in the tail of discovery of 1955 L1 by Antonin meeting Mr Lynn gave a paper on comet 1903 M1. The comet Mrkos who “had built his own “Dorfel and the Comet of 1680”. section report for the year to little observatory at the top of Mt Dorfel was born in Plauen in September 30 notes “The comets Lomnica (2630m), the 2nd highest 1643, and was a pupil of of the last twelve months have not peak in the Tatra mountains, Hevelius.
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