103P/Hartley

Jupiter-family comet Hartley 2 other comets Comet Hartley (disambiguation)Comet Hartley August 2024 103P/Hartley ' h ɑ:r t l i Introducing Comet Hartley 2.png The nucleus of Comet Hartley 2 photographed by the Deep Impact (EPOXI) mission on November 2010 IAUC_4197 Malcolm Hartley Siding Spring, Australia 15 March 1986 P/1986 E2, P/1991 N1 1985 V, 1991 XV 1986c, 1991t MPC1 jpl1 5 May 2025 (JD 2460800.5) 20.44 years 8,857 1.06 AU 5.89 AU 3.48 AU 0.694 6.48 years 13.608° 219.76° 181.33° 86.789° 2.642 0.072 AU 0.277 AU jpl1 0.58 0.018 kmThomas_2013 200 – 400 kg/m3Thomas_2013 300 Mt kg lb 0.028Lisse_2009 18.1 hours 16.0 12 October 2023 5 April 2030Horizons2030 Comet Hartley 2, designated 103P/Hartley by the Minor Planet Center,MPC2 is a small periodic comet with an orbital period of 6.48 years.MPC1 It was discovered by Malcolm Hartley in 1986 at the Schmidt Telescope Unit, Siding Spring Observatory, Australia.jpl1 Its diameter is estimated to be 1.2 – 1.6 km mijpl1 A'Hearn_2007 Hartley 2 was the target of a flyby of the Deep Impact spacecraft, as part of the EPOXI mission, on 4 November 2010,Tune_2007 which was able to approach within 700 km mi of Hartley 2 as part of its extended mission.Lisse_2009 2010 11 Hartley 2 is the smallest comet which has been visited.Beatty_2010 It is the fifth comet visited by spacecraft, and the second comet visited by the Deep Impact spacecraft, which first visited comet Tempel 1 on 4 July 2005.Tune_2010 Discovery and orbit Comet Hartley 2 is a small Jupiter-family comet having an orbital period of 6.46 years. It was discovered by Malcolm Hartley in 1986 at the Schmidt Telescope Unit, Siding Spring Observatory, Australia. It has the perihelion near the Earth's orbit at 1.05 AU e6km unit from the Sun.jpl1 2010 Earth approach The comet passed within 0.12 AU e6km unit of Earth on 20 October 2010,jpl1 only eight days before coming to perihelion on 28 October 2010.jpl1 From northern latitudes, during early November 2010, the comet was visible around midnight without interference from the Moon.moon2010 The comet reached an apparent magnitude of about 5 and became dimly visible by naked eye.cobs_103p 2023 Earth approach On 26 September 2023 the comet passed 57268126 144 km from Earth.jpl1 It came to perihelion on 12 October 2023 and brightened to about magnitude 8.Yoshida-103p CA2023 +103P/Hartley Closest Earth Approach on 2023-Sep-26 05:44 UTjpl1 Date & time ofclosest approach Earth distance(AU) Sun distance(AU) Velocitywrt Earth(km/s) Velocitywrt Sun(km/s) Uncertaintyregion(3-sigma) Reference 2023-09-26 05:28 ± <1 min 0.3828 AU e6km unit 1.088 AU e6km unit 18.3 37.1 ± 144 km Horizons Despite its current close passage by Earth's orbit, the comet is not yet a known source of meteor showers. However, that could change. Dust trails from the recent returns of 103P/Hartley 2 move in and out of Earth's orbit, and the 1979-dust trail is expected to hit in 2062 and 2068.Jenniskens_2006 Characteristics thumb|right|Comet 103P/Hartley closeup, from EPOXI. Observation by the Spitzer Space Telescope in August 2008 showed the comet nucleus to have a radius of 0.57 ± 0.08 km mi and a low albedo of 0.028.Lisse_2009 The mass of the comet is estimated to be about 300 Mt kg.Lisse_2009 Barring a catastrophic breakup or major splitting event, the comet should be able to survive up to another 100 apparitions (~700 years) at its current rate of mass loss.Lisse_2009 Radar observations by the Arecibo Observatory during the comet's 2010 apparition revealed that the nucleus is highly elongated and rotates over an 18-hour period. The project manager of the EPOXI mission described its shape as "a cross between a bowling pin and a pickle".jpl3 In 2011 Herschel Space Observatory detected the signature of vaporized water in the comet's coma. Hartley 2 contains half as much heavy water as other comets analyzed before, with the same ratio between heavy water and regular water as found in Earth's oceans.dailygalaxy1 jpl4 For many years, it was known that few comets produced more water vapor than it should by the redirection of nucleus of water ice. The flyby of Hartley 2 showed that many of the icy grains in the coma are driven out by the outgassing of carbon dioxide. It is believed that this is the source of much of the water coming from the comet.July 2026 Observations of Hartley 2 showed the importance of carbon-monoxide ice to carbon-dioxide ice in comets. After a reexamination, it was found that the abundances of carbon-monoxide ice and carbon dioxide ice show that short-period comets formed under warmer conditions, than the longer period comets. This shows that the short-period comets formed closer to the Sun, than the long-term comets. This discovery goes well with the measurements of Heavy Water in Hartley 2.jpl2 Deep Impact flyby right 10-1009_comet103p_vcastro-ccsa3.0.jpg 103P with Double Cluster in Perseus 9 October 2010. Hartley_2_Epoxi_2Mkm.jpg Comet Hartley 2 on 2 November 2010 from a distance of 2.3 million kilometers, as photographed by the Deep Impact spacecraft. The Deep Impact spacecraft, which had previously photographed Comet Tempel 1, was reused by NASA to study Hartley 2. The initial plan was for a flyby of Comet Boethin. However, Boethin had not been observed since 1986, and its orbit could not be calculated with sufficient precision to permit a flyby, so NASA re-targeted the spacecraft toward Hartley 2 instead.A'Hearn_2007 The spacecraft came within 700 km mi while moving at 44300 km/h mi/h on 4 November 2010.Grossman_2010 The data from the flyby were transmitted back to Earth through NASA's Deep Space Network.Tune_2010 The flyby was able to show that the comet is 2.25 km mi long, and "peanut shaped". Some jets of material are being ejected from the dark side of the comet, rather than the sunlit side. Scientists involved in the EPOXI mission describe the comet as being unusually active, with mission scientist Don Yeomans stating that "It's hyperactive, small and feisty."Black_2010 NASA's scientists reported that the rays coming off the rough ends consist of hundreds of tons of fluffy ice and dust chunks – the largest particles are of golf ball to basketball-size – and they are ejected by jets of carbon dioxide.NYT-20101119 The scientists also said that it was the first time that comet activity powered by sublimation of frozen carbon dioxide had been observed as the comet neared the Sun; the ice within the comet must be primordial, dating from the beginnings of the Solar System.Cowen_2010 Results thumb|right|Animation of Deep Impact trajectory from 12 January 2005 to 8 August 2013 magenta Deep Impact 1 lime Tempel 1 royalblue Earth cyan 103P/Hartley The EPOXI mission flyby showed that the material being ejected from the comet is primarily composed of gas. Michael A'Hearn, the science team leader for the EPOXI mission, stated: "Early observations of the comet show that, for the first time, we may be able to connect activity to individual features on the nucleus".Tune_2010 thumb|right|Flyby of Comet Hartley 2 on 4 Nov. 2010 by Deep Impact (EPOXI) A University of Maryland-led study published in 17 June issue of the journal Science described an analysis of the mission.A'Hearn_2011 Key findings from the mission include: (1) the smooth, relatively inactive waist of the peanut shaped comet has probably been re-deposited; (2) Hartley 2 spins around one axis, but also tumbles around a different axis; and (3) on its larger, rougher ends, the comet's surface contains glittering, blocky objects that are about 165 ft m high and 260 ft m wide (as big as a 16-story building). Moreover, these objects appear to be two to three times more reflective than the surface average. "Hartley 2 is a hyperactive little comet, spewing out more water than other comets its size", said University of Maryland Astronomer Michael A'Hearn, who is lead author on the Science paper and principal investigator for the EPOXI and Deep Impact missions. "When warmed by the Sun, dry ice [frozen carbon dioxide] deep in the comet's body turns to gas jetting off the comet and dragging water ice with it." It is now believed that some of the dust, icy chunks, and other material coming off the ends of the comet are moving slowly enough to be captured by even the weak gravity of the comet, this material then falls back into the lowest point of the comet, which is the middle.A'Hearn_2011 UMD1 See also List of minor planets and comets visited by spacecraft 9P/Tempel 81P/Wild References M. F. A'Hearn EPOXI Mission Status NASA University of Maryland http://epoxi.umd.edu/1mission/status.shtml 2007-12-02 2010-11-07 2010-11-15 https://web.archive.org/web/20101115215854/http://epoxi.umd.edu/1mission/status.shtml live M. F. A'Hearn M. J. S. Belton W. A. Delamere L. M. Feaga D. Hampton etal EPOXI at Comet Hartley 2 Science 2011 332 6036 1396–1400 2011Sci...332.1396A 10.1126/science.1204054 21680835 K. Beatty Mr. Hartley's Amazing Comet https://skyandtelescope.org/astronomy-news/mr-hartleys-amazing-comet/ Sky & Telescope 4 November 2010 5 November 2010 7 November 2010 https://archive.today/20101107194918/http://www.skyandtelescope.com/news/106720468.html live S. Black NASA Deep Impact probe sends images of Hartley 2 comet from space https://www.news.com.au/technology/science/nasa-deep-impact-probe-sends-images-of-hartley-2-comet-from-space/news-story/52807bfffcb481792e5feccb15881670 news.com.au News Limited 2010-11-05 2010-11-06 2010-11-07 https://web.archive.org/web/20101107005209/http://www.news.com.au/technology/sci-tech/nasa-deep-impact-probe-sends-images-of-hartley-2-comet-from-space/story-fn5fsgyc-1225948133581 live Observation list for Comet 103P/Hartley https://cobs.si/obs/comet/80/ COBS – Comet OBServation database 2023-08-05 R. Cowen A Cometary Blizzard https://www.sciencenews.org/article/cometary-blizzard Science News 2010-11-18 2023-01-04 2010-11-22 https://web.archive.org/web/20101122131412/http://www.sciencenews.org/view/generic/id/65779/title/A_cometary_blizzard live Space Observatory Links Early Oceans to Icy Comets http://www.dailygalaxy.com/my_weblog/2011/10/new-measurements-from-the-herschel-space-observatory-show-that-comet-hartley-2-which-comes-from-the-distant-kuiper-belt.html The Daily Galaxy 2011-10-07 2011-10-09 2017-12-01 https://web.archive.org/web/20171201034409/http://www.dailygalaxy.com/my_weblog/2011/10/new-measurements-from-the-herschel-space-observatory-show-that-comet-hartley-2-which-comes-from-the-distant-kuiper-belt.html dead L. Grossman New Super Close-Up Images From Comet Flyby https://www.wired.com/wiredscience/2010/11/epoxi-comet-flyby/ Wired Condé Nast Digital 2010-11-04 2010-11-06 2010-11-07 https://web.archive.org/web/20101107010933/http://www.wired.com/wiredscience/2010/11/epoxi-comet-flyby/ live Horizons Batch for 103P/Hartley on 2030-Apr-05 JPL Horizons Perihelion occurs when rdot flips from negative to positive https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D103P%3BCAP%27&START_TIME=%272030-Apr-03%27&STOP_TIME=%272030-Apr-08%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27 2023-07-15 (JPL#K234/9 Soln.date: 2023-Jul-06) M. Hartley D. W. Green Comet Hartley (1986c) http://www.cbat.eps.harvard.edu/iauc/04100/04197.html IAU Circular 1986-03-20 4197 1 1986IAUC.4197....1H P. Jenniskens P. M. M. Jenniskens Meteor Showers and their Parent Comets Cambridge University Press 2006 688 978-0-521-85349-1 103P/Hartley – JPL Small-Body Database Lookup https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=103P ssd.jpl.nasa.gov Jet Propulsion Laboratory 2023-07-12 D. C. Brown NASA's Deep Impact Produced Deep Results http://www.jpl.nasa.gov/news/news.php?release=2013-286 NASA / JPL 2013-09-20 2013-10-24 D. C. Agle Space Radar Provides a Taste of Comet Hartley 2 https://www.jpl.nasa.gov/news/space-radar-provides-a-taste-of-comet-hartley-2/ NASA / JPL 2010-10-28 2010-11-07 Heavy and Light Just Right https://www.jpl.nasa.gov/images/pia14737-heavy-and-light-just-right/ NASA / JPL 2011-10-05 2011-10-09 C. M. Lisse Y. R. Fernandez W. T. Reach J. M. Bauer M. F. A'Hearn T. L. Farnham O. Groussin M. J. Belton K. J. Meech C. D. Snodgrass 5 Spitzer Space Telescope Observations of the Nucleus of Comet 103P/Hartley 2 https://authors.library.caltech.edu/records/mm2a0-hqk90/files/Lisse2009p5855Publ_Astron_Soc_Pac.pdf Publications of the Astronomical Society of the Pacific 2009 121 883 968–975 2009PASP..121..968L 0906.4733 17318657 10.1086/605546 free 2010 Phases of the Moon http://aa.usno.navy.mil/cgi-bin/aa_moonphases.pl?year=2010 U.S. Naval Observatory 2010-10-18 2011-07-22 https://web.archive.org/web/20110722211607/http://aa.usno.navy.mil/cgi-bin/aa_moonphases.pl?year=2010 dead 103P/Hartley Orbit https://minorplanetcenter.net/db_search/show_object?object_id=103p Minor Planet Center 2025-03-10 Periodic Comet Numbers http://www.minorplanetcenter.org/iau/lists/PeriodicCodes.html Minor Planet Center 2010-11-07 2010-11-06 https://archive.today/20101106015203/http://www.minorplanetcenter.org/iau/lists/PeriodicCodes.html live K. Chang Comet Hartley 2 Is Spewing Ice, NASA Photos Show https://www.nytimes.com/2010/11/19/science/space/19comet.html?hpw The New York Times 2010-11-18 2010-11-21 P. C. Thomas M. F. A'Hearn J. Veverka etal Shape, density, and geology of the nucleus of Comet 103P/Hartley 2 https://ntrs.nasa.gov/api/citations/20140009994/downloads/20140009994.pdf Icarus 2013 222 2 550–558 2013Icar..222..550T 10.1016/j.icarus.2012.05.034 2060/20140009994 L. Tune B. Steigerwald G. Hautaluoma D. C. Agle Deep Impact Extended Mission Heads for Comet Hartley 2 http://www.newsdesk.umd.edu/scitech/release.cfm?ArticleID=1564 University of Maryland 2007-12-13 2009-08-07 2009-06-20 https://web.archive.org/web/20090620043143/http://www.newsdesk.umd.edu/scitech/release.cfm?ArticleID=1564 dead L. Tune D. C. Agle D. C. Brown UMD Leads Deep Impact Spacecraft on Successful Flyby of Comet Hartley 2 http://epoxi.umd.edu/7press/news/20101104c.shtml NASA 2010-11-04 2010-11-07 2012-12-12 https://archive.today/20121212115233/http://epoxi.umd.edu/7press/news/20101104c.shtml live University of Maryland Comet Hartley 2 in hyperactive class of its own: CO2 jets confirmed, new insight into composition, 'excited' rotation https://www.sciencedaily.com/releases/2011/06/110616142706.htm Science Daily 2011-06-16 2023-01-04 S. Yoshida 103P/Hartley 2 http://www.aerith.net/comet/catalog/0103P/index.html www.aerith.net 16 July 2006 2010-02-23 2010-03-25 https://web.archive.org/web/20100325002249/http://www.aerith.net/comet/catalog/0103P/index.html live External links yes 1000041 103P 103P/Hartley at the Minor Planet Center database 103P/Hartley at Seiichi Yoshida's website 103P/Hartley at Gary W. Kronk's Cometography Cometary Science Center webpage for comet 103P Ferrín Ignacio Secular light curve of comet 103P/Hartley 2, target of the EPOXI mission Planetary and Space Science 2010 58 14–15 1868–1879 10.1016/j.pss.2010.08.017 1008.4556 2010P&SS...58.1868F Amateur images, tracking and observation reports of 103P/Hartley 2 during the 2010 pass https://web.archive.org/web/20110427085159/http://www.astrokev.com/category/astrophotography/comets-astrophotography/103p-hartley-2/ 27 April 2011 Finder chart and observation reports from Society for Popular Astronomy during October 2010January 2018 InternetArchiveBot yes 5 November 2010 Photos of Hartley 2 102P/Shoemaker 104P/Kowal Category:Periodic comets 103P 0103 Category:Discoveries by Malcolm Hartley Category:Comets visited by spacecraft 103P 103P *