2006 RH120

Temporary satellite of Earth February 2021 yes #FFC2E0 2006 RH 120 2006 RH120 at Mt. Lemmon Survey.jpg 2006 RH 120 from Mt. Lemmon Survey in December 2006 Catalina Sky Survey (Eric Christensen) 14 September 2006 11 September 2006 2006 RH 120 6R10DB9 Amor (MPC 2013)WayBack: MPC Epoch 2013 = Amor Apollo (JPL 2012)archive.ph: https://archive.today/20121213133329/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2006RH120 JPL Epoch 2012 = Apollo Aten (2007)archive.ph: https://archive.today/20150224153834/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2006RH120 Epoch Jan 2007 = Aten with a=0.99au (Temporary satellite of Earth 2006–2007) 27 April 2019 (JD 2458600.5) 1 281 days 1.058 AU Gm on on (Q) 1.0078 AU Gm on (q) ~2028-Nov-11 1.0331 AU Gm on (a) 0.02452 (e) 1.05 yr 0.59486° (i) 51.18° (Ω) 313.7° (M) 10.060° (ω) 0.01682 AU km on 3.93 AU Gm on ~2–3 m 2.75 minutes 0.04583 h min on on 0.1 ?March 2020 ? 29.5 30+ (until 2027) 2006 RH 120 is a tiny near-Earth asteroid and fast rotator with a diameter of approximately 2–3 meters that ordinarily orbits the Sun but makes close approaches to the Earth–Moon system around every twenty years, when it can temporarily enter Earth orbit through temporary satellite capture (TSC). Most recently, it was in Earth orbit from July 2006 to July 2007, during which time it was never more than 0.0116 AU e6km unit on from Earth. As a consequence of its temporary orbit around the Earth, it is currently the second smallest asteroid in the Solar System with a well-known orbit, after 2021 GM 1. Until it was given a minor planet designation on 18 February 2008, the object was known as 6R10DB9, an internal identification number assigned by the Catalina Sky Survey.http://www.birtwhistle.org/Gallery6R10DB9.htm 2006 RH120 ( = 6R10DB9) – A second moon for the Earth? Great Shefford Observatory 16 April 2008 https://web.archive.org/web/20080509212342/http://www.birtwhistle.org/Gallery6R10DB9.htm 9 May 2008 dead Discovery 2006 RH 120 was discovered on 14 September 2006 by Eric Christensen with the 27 in mm on Schmidt camera of the Catalina Sky Survey in Arizona.http://cfa-www.harvard.edu/~gwilliams/DASO/000000/DASO_000068.txt Distant Artificial Satellites Observation (DASO) Circular No. 68, 2006 Sept. 17, 16:59 UT 26 June 2007 "6R10DB9" was the Catalina Sky Survey's own discovery designation for this object, which usually would only be used on the Minor Planet Center's (MPC) Near-Earth Object Confirmation Page (NEOCP) until an International Astronomical Union (IAU) designation was applied, if the object was classified as a minor object. It was added on 14 September to the NEOCP and subsequently removed with the explanation that it "was not a minor planet".http://www.hohmanntransfer.com/news/0704.htm#news Major News About Minor Objects, April 18, 2007 27 June 2007 27 November 2012 https://web.archive.org/web/20121127050228/http://hohmanntransfer.com/news/0704.htm#news dead Preliminary orbital calculations indicated it was captured by Earth's gravity from solar orbit of a period of about 12 months, which is similar to that of many spent rocket boosters dating to the Apollo program of the 1960s and early 1970s. 6R10DB was assigned the designation 2006 RH 120 on 18 February 2008. Precovery observations from Catalina Sky Survey, taken on 11 September 2006, were published on 31 July 2026 (almost twenty years later). Origin Some controversy existed regarding the origin of the object. Upon discovery, it was not given a formal name because its spectrum was consistent with the white titanium-oxide paint used on Saturn V rockets,Spectrum measured by Carl Hergenrother and Rob Whitely of the University of Arizona. which meant it could be an artificial object. Precedents for this exist: J002E3 is currently thought to be the third-stage Saturn S-IVB booster from Apollo 12 and was in an almost identical orbit,Is Another Moon Possible? Yeomans Don April 2010 Astronomy and 6Q0B44E, discovered a month earlier, was also thought to be artificial.The Guardian, Spacewatch, 6 September 2006 Its status as a satellite was also debated, with A. W. Harris of the Space Science Institute commenting, "Claiming some bit of fluff in a temporary looping orbit to be a 'satellite', with all the baggage that term carries, is mere hype".17 April 2007 Earth's "Other Moon" Sky & Telescope Roger W. Sinnott https://skyandtelescope.org/astronomy-news/earths-other-moon/ 25 February 2010 https://web.archive.org/web/20120402120646/http://www.skyandtelescope.com/news/7067527.html 2 April 2012 live Radar observations strongly suggest that the object is a natural body. Orbit Analysis has shown that solar-radiation pressure is perturbing its motion perceptibly.20 June 2007 6R10DB9 Planning http://echo.jpl.nasa.gov/asteroids/6R10DB9/6R10DB9_planning.html JPL/NASA Asteroid Radar Research Dr. Lance A. M. Benner 27 February 2010 However, Paul Chodas in JPL's Solar System Dynamics Group suspects that the perturbations are consistent with expectations for a rocky object but not with old flight hardware. One hypothesis is that the object is a piece of lunar rock ejected by an impact.http://www.projectpluto.com/pluto/mpecs/6r1.htm Bill Gray 16 August 2007 "Pseudo-MPEC" for 6R10DB9 https://web.archive.org/web/20070927183814/http://home.gwi.net/~pluto/mpecs/6r1.htm 27 September 2007 live In 2023, 2006 RH 120 was identified as a possible dark comet. 4 2 subscription Dark Comets? Unexpectedly Large Nongravitational Accelerations on a Sample of Small Asteroids 10.3847/PSJ/acb697 free https://iopscience.iop.org/article/10.3847/PSJ/acb697 2023-02-15 The Planetary Science Journal 2025-07-13 en Darryl Z. Seligman 10150/674306 free 2212.08115 Dark comets are asteroids that exhibit comet-like acceleration, but visually appear as asteroids, with no coma or tail. Dark Comets https://www.scientificamerican.com/article/mysterious-dark-comets-could-unlock-solar-system-secrets/ May 2025 2025-05-01 Scientific American 2025-11-28 en 58–63 Astronomers who study dark comets believe the acceleration is caused by outgassing on the sunlit side. 2006 RH 120 made four Earth orbits of about three months each with perigee (closest approach to Earth) on 11 September 2006, 3 January 2007, 25 March 2007, and 14 June 2007. During the 12-month capture from July 2006 to July 2007 when it was inside of Earth's Hill sphere, it stayed within 0.0116 AU e6km unit on of Earth. It was ejected after the 14 June 2007 perigee when it dipped inside the Moon's orbit to a distance of 276840 km mi. 2006 RH 120 became an Apollo-class asteroid in June 2007 as it was escaping Earth's Hill sphere. Though it was outside of Earth's Hill sphere, the geocentric orbital eccentricity was not greater than 1 until 17 September 2007. It is now in solar orbit as an Amor-class asteroid with an orbit completely outside of Earth's orbit. As of 2022, this object is 1.7 AU from Earth on the other side of the Sun and was not less than 1 AU from Earth until March 2025. Future events Around 18 August 2028 (±3 days) it will pass Earth with a relative velocity of 136 m/s mph on2006 RH120 https://www.spacereference.org/asteroid/2006-rh120 2022-06-12 Space Reference and will then pass Earth with a relative velocity of 784 m/s mph on around 9 October 2028 as it speeds up for a November 2028 perihelion passage (closest approach to the Sun and when an object moves fastest in its orbit). For comparison, on 13 April 2029, asteroid 99942 Apophis will pass Earth at a relative speed of 7.4 km/s mph on. 2006 RH 120 has a 1-in-120 (0.8%) chance of Earth impact on 8 February 2044 and would impact with a harmless 1.3 kiloton of energy if it did impact. (The Chelyabinsk meteor released about 440 kt of energy.) JPL Horizon's nominal orbit has the asteroid passing 0.009 AU e6km unit on from Earth on 9 January 2044 (30 days before the virtual impactor). As a result of a 281 day observation arc and radar observations, JPL's solution accounts for non-gravitational forces as the multi-decade motion of a very small object is greatly affected by solar radiation pressure and the Yarkovsky effect.August 2026 +2044 Virtual impactor Date Impactprobability(1 in) JPL Horizonsnominal geocentricdistance (AU) NEODySnominal geocentricdistance (AU) MPCnominal geocentricdistance (AU) Find_Orbnominal geocentricdistance (AU) uncertaintyregion(3-sigma)2044-02-08 09:07 200 0.014 AU e6km unit on 0.223 AU e6km unit 0.10 AU e6km unit 0.23 AU e6km unit ± 130 million km thumb|right|Orbit of 2006 RH 120 during a temporary-satellite-capture event left horizontal 280 Animation of 2006 RH 120 orbit Animation of 2006 RH120 orbit around Earth 20060401-20071101.gif Around Earth from April 2006 to November 2007 Animation of 2006 RH120 orbit around Earth 1978-2020.gif Around Earth from 1978 to 2020 Animation of 2006 RH120 orbit around Sun 1600-2500.gif Around Sun from 1600 to 2500 Yellow Sun RoyalBlue Earth Darkkhaki MoonMagenta 2006 RH 120 14 June 2007 perigee On 14 June 2007, 2006 RH 120 made its fourth and last perigee of the most recent Earth encounter. It was 0.72 lunar distances at closest, with an apparent magnitude of 18.5–19.0. Astronomers at JPL Goldstone in California made radar astrometry measurements on 12, 14 and 17 June 2007. 2006 RH 120 is listed as part of the Near-Earth Object Human Space Flight Accessible Targets Study (NHATS). See also 1991 VG temporary Earth satellite discovered in 1991 2020 CD 3 another temporary Earth satellite discovered in 2020 2022 NX 1 another temporary Earth satellite discovered in 2022 2023 FY 3 another temporary Earth satellite discovered in 2023 2024 PT 5 another temporary Earth satellite discovered in 2024 6Q0B44E small Earth satellite, probably artificial 3753 Cruithne horseshoe companion of the Earth 2002 AA 29 horseshoe companion of the Earth (419624) 2010 SO 16 horseshoe companion of the Earth Natural satellite Claimed moons of Earth Quasi-satellite Space debris Dark comet References 30em 18 February 2008 MPEC 2008-D12 : 2006 RH120 Gareth V Williams IAU Minor Planet Center Harvard–Smithsonian Center for Astrophysics https://minorplanetcenter.net//mpec/K08/K08D12.html https://web.archive.org/web/20100409062729/http://www.cfa.harvard.edu/mpec/K08/K08D12.html 9 April 2010 live 26 February 2010 31 July 2026 MPEC 2026-O106 : DAILY ORBIT UPDATE (2026 July 31) A. U. Tomatic IAU Minor Planet Center Harvard–Smithsonian Center for Astrophysics https://minorplanetcenter.net/mpec/K26/K26OA6.html https://web.archive.org/web/20260803082717/https://minorplanetcenter.net/mpec/K26/K26OA6.html 3 August 2026 live 3 August 2026 2006 RH120 Orbit Minor Planet Center http://www.minorplanetcenter.net/db_search/show_object?object_id=2006+RH120 https://archive.today/20140225004040/http://www.minorplanetcenter.net/db_search/show_object?object_id=2006+RH120 25 February 2014 live 2017-02-07 last observation: 2007-06-22; arc: 281 days JPL Small-Body Database Browser: (2006 RH120) https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2006RH120&view=OPC https://archive.today/20140227160615/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2006RH120;cad=1%23cad 2014-02-27 live 30 March 2016 Earth Impact Risk Summary: 2006 RH120 NASA/JPL Near-Earth Object Program Office https://cneos.jpl.nasa.gov/sentry/details.html#?des=2006%20RH120 https://archive.today/20220613074411/https://cneos.jpl.nasa.gov/sentry/details.html%23?des=2006%20RH120 2022-06-13 live 2026-08-03 Horizons Batch for July 2006 – July 2007 Geocentric distance Maximum Apogee occurs 2006-Nov-03 18:54 @ 0.011654 AU JPL Horizons https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272006+RH120%27&START_TIME=%272006-Jul-01%27&STOP_TIME=%272007-Jul-14%27&STEP_SIZE=%271%20day%27&QUANTITIES=%2720%27 https://web.archive.org/web/20220709140414/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272006+RH120%27&START_TIME=%272006-Jul-01%27&STOP_TIME=%272007-Jul-14%27&STEP_SIZE=%271%20day%27&QUANTITIES=%2720%27 2022-07-09 live 2022-07-07 (JPL#51/Soln.date: 2021-Apr-14) (NEODyS-2 for 3 Nov 2006) JPL Horizons On-Line Ephemeris for 2006 RH120 orbit of Earth (geocentric) at epoch 2007-Sep-17 https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272006+RH120%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272007-Sep-17%27&STOP_TIME=%272007-Sep-18%27&STEP_SIZE=%271%20day%27&CENTER=%27@399%27&OUT_UNITS=%27AU-D%27 JPL Horizons On-Line Ephemeris System Jet Propulsion Laboratory 2022-07-12 Geocentric solution. Ephemeris Type: Orbital Elements / Center: @399 Horizons Batch for 2028 approaches JPL Horizons https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272006+RH120%27&START_TIME=%272028-06-01%27&STOP_TIME=%272028-11-12%27&STEP_SIZE=%271%20day%27&QUANTITIES=%279,19,20,22,23,39%27 2022-06-13 Horizons Batch for Jan 2044 – Feb 2044 Geocentric distance Earth approach occurs 2044-Jan-29 12:34 @ 0.006885 AU JPL Horizons https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272006+RH120%27&START_TIME=%272044-Jan-01%27&STOP_TIME=%272044-Feb-18%27&STEP_SIZE=%271%20day%27&QUANTITIES=%2720%27 2022-07-10 (JPL#51/Soln.date: 2021-Apr-14) Horizons Batch for 2044-02-08 09:07 Virtual Impactor JPL Horizons https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272006+RH120%27&START_TIME=%272044-02-08%2009:07%27&STOP_TIME=%272044-02-09%27&STEP_SIZE=%271%20day%27&QUANTITIES=%2720,39%27 https://web.archive.org/web/20220707175350/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272006+RH120%27&START_TIME=%272044-02-08+09%3A07%27&STOP_TIME=%272044-02-09%27&STEP_SIZE=%271+day%27&QUANTITIES=%2720%2C39%27 2022-07-07 live 2022-07-07 RNG_3sigma = uncertainty range in km. (JPL#51/Soln.date: 2021-Apr-14 generates RNG_3sigma = 78335191 km for 2044-Feb-08 09:07.) 2006RH120 Ephemerides for 8 February 2044 NEODyS (Near Earth Objects Dynamic Site) https://newton.spacedys.com/neodys/index.php?pc=1.1.3.1&n=2006RH120&oc=500&y0=2044&m0=02&d0=08&h0=09&mi0=07&y1=2044&m1=02&d1=08&h1=09&mi1=07&ti=1.0&tiu=minutes https://web.archive.org/web/20220707180413/https://newton.spacedys.com/neodys/index.php?pc=1.1.3.1&n=2006RH120&oc=500&y0=2044&m0=02&d0=08&h0=09&mi0=07&y1=2044&m1=02&d1=08&h1=09&mi1=07&ti=1.0&tiu=minutes 2022-07-07 live 2022-07-07 MPC Ephemeris Service IAU Minor Planet Center https://minorplanetcenter.net//iau/MPEph/MPEph.html 2022-07-07 Find_Orb for 2044-02-08 Project Pluto https://www.projectpluto.com/cgi-bin/fo/fo_serve.cgi?obj_name=2006+RH120&year=2044-02-08&n_steps=1&stepsize=1 https://web.archive.org/web/20220707182023/https://www.projectpluto.com/cgi-bin/fo/fo_serve.cgi?obj_name=2006+RH120&year=2044-02-08&n_steps=1&stepsize=1 2022-07-07 live 2022-07-07 Accessible Near-Earth Objects (NEOs) Brent W. Barbee 12th Meeting of the Small Bodies Assessment Group (SBAG) 2015 http://www.lpi.usra.edu/sbag/meetings/jan2015/presentations/SBAG12_Accessible_NEOs_Barbee.pdf 12 January 2015 (pg 17 for diameter) 2006RH120 Ephemerides for 2007 to 2028 NEODyS (Near Earth Objects Dynamic Site) https://newton.spacedys.com/neodys/index.php?pc=1.1.3.1&n=2006RH120&oc=500&y0=2007&m0=1&d0=1&h0=0&mi0=0&y1=2028&m1=1&d1=1&h1=0&mi1=0&ti=365.3&tiu=days 24 February 2015 JPL Close-Approach Data: 99942 Apophis (2004 MN4) https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=Apophis&view=OPC 15 February 2015 NHATS Object/Trajectory Details: (2006 RH120) http://neo.jpl.nasa.gov/cgi-bin/nhats?sstr=2006RH120 https://archive.today/20150224153151/http://neo.jpl.nasa.gov/cgi-bin/nhats?sstr=2006RH120 dead 24 February 2015 24 February 2015 Photometry of 2006 RH120: an asteroid temporary captured into a geocentric orbit Astronomy & Astrophysics Kwiatkowski T. Kryszczyńska A. Polińska M. Buckley D. A. H. O'Donoghue D. Charles P. A. Crause L. Crawford S. Hashimoto Y. Kniazev A. https://www.aanda.org/articles/aa/full_html/2009/09/aa10965-08/aa10965-08.html en 495 3 967–974 2009 10.1051/0004-6361:200810965 2009A&A...495..967K 0004-6361 free External links Great Shefford Observatory's 6R10DB9 images and background Earth's "Other Moon", Roger W. Sinnott, Sky & Telescope, 17 April 2007 JPL Radar Astrometry Page Bill Gray's Pseudo-MPEC Page on 6R10DB9 Photometry of 2006 RH120: an asteroid temporarily captured into a geocentric orbit (Astronomy & Astrophysics 2009) Interactive 3D visualisation of the Earth 2006 RH120 capture event 2006+RH120 2006RH120 3403148 # Category:Minor planet object articles (unnumbered) # Category:Claimed moons of Earth # 20060911 20070614 20060914