164207 Cardea

Sub-kilometer asteroid and quasi-satellite of Earth September 2020 yes 164207 Cardea #FFC2E0 2004 GU9 CFHT 2007-02-09 annotated.gif Cardea photographed by the Canada–France–Hawaii Telescope in February 2007 LINEAR Lincoln Lab's ETS 13 April 2004 (164207) Cardea Cardea ' k ɑːr d i ə NEOApollo 2004 GU 9 164207 Cardea (2004 GU9) 2164207 1 November 2025 21 November 2025 (JD 2461000.5) 8688 days (23.79 yr) 0 1.1372 AU Gm on on 0.8650 AU Gm on 1.0011 AU Gm on 0.1359 1.0017 yr (365.87 d) 0.98373997 ms / day 97.3298° 13.6529° 38.3866° 280.55672 0.00007° 2456145.53817 0.00006 jd 279.3410° 0.0031 AU km on 163 m2988 0.2192988 21.1 164207 Cardea (provisional designation 2004 GU 9) is a sub-kilometer asteroid, classified as a near-Earth object and potentially hazardous asteroid of the Apollo group. It is a quasi-satellite of Earth, a situation that should persist until around 2600, when it is expected to shift to a regular horseshoe orbit for a few thousand years. On 14 April 2004 (with less than a 1-day observation arc), the Sentry Risk Table showed 180 virtual impactors.2004-04-14 Major News about Minor Objects: Risk monitoring hohmanntransfer http://www.hohmanntransfer.com/mn/0404/14.htm#risks 2 March 2015 6 November 2020 https://web.archive.org/web/20201106091029/http://www.hohmanntransfer.com/mn/0404/14.htm#risks dead It was removed from the Sentry Risk Table 2 days later on 16 April 2004.Date/Time Removed NASA/JPL Near-Earth Object Program Office http://neo.jpl.nasa.gov/risk/removed.html https://web.archive.org/web/20020602101400/http://neo.jpl.nasa.gov/risk/removed.html dead 2002-06-02 2015-03-01 As later precovery observations by Haleakala-AMOS from 2001 have been found, Cardea now has a well determined orbit with an observation arc of 24 years. Discovery and naming This asteroid was discovered on 13 April 2004 by the Lincoln Near-Earth Asteroid Research (LINEAR) project near Socorro, New Mexico and given the provisional designation 2004 GU 9. Following the naming of 524522 Zoozve, a quasi-satellite of Venus, Radiolab and the International Astronomical Union held a public naming campaign for this quasi-satellite from June to September 2024. Seven finalist names were revealed in December 2024, with the names being Bakunawa, Cardea, Ehaema, Enkidu, Ótr, Tarriaksuk, and Tecciztecatl. The winning name was Cardea, the Roman goddess of hinges. The name was announced by the International Astronomical Union on 13 January 2025. Orbit Cardea orbits the Sun with a semi-major axis of 1.001 astronomical units (AU), taking 365.87 days to complete one orbit. It is classified as a near-Earth asteroid (NEA) and an Apollo asteroid; Apollo asteroids are NEAs that cross Earth's orbit but have semi-major axes above 1 AU. Its orbit is inclined by 13.653° with respect to the ecliptic plane. Along its orbit, its distance from the Sun varies from 0.865 AU at perihelion to 1.137 AU at aphelion due to its moderate2987 orbital eccentricity of 0.136. Cardea is in a 1:1 mean-motion resonance with Earth, and it currently orbits in a quasi-satellite configuration.489 Quasi-satellites have principal libration angles Where and are the mean longitudes of Cardea and Earth, respectively that librate around 0°,488 appearing to distantly orbit Earth from its perspective despite directly orbiting the Sun. All Earth quasi-satellites are temporary; Cardea has been a quasi-satellite for about 600 years, and will eventually lose its status as one in about 500 years. Perturbations from Venus play a role in destabilizing Cardea from its quasi-satellite configuration even though their orbits do not cross. Currently, the libration of Cardea's has an amplitude of 8–10°, with a libration period of 70 years. After exiting its quasi-satellite phase, it will enter a horseshoe configuration.490–491 Physical characteristics Cardea has a diameter of 163 m ft and an albedo of 0.219.2988 left horizontal 300 Animation of 164207 Cardea's orbit from 1600 to 2500 Animation of 2004 GU9's orbit relative to Sun and Earth.gif Relative to Sun and Earth Animation of 2004 GU9's orbit around Earth.gif Around Earth Animation of 2004 GU9's orbit around Sun.gif Around Sun Yellow Sun RoyalBlue EarthMagenta Cardea See also (277810) 2006 FV 35, another quasi-satellite of Earth Notes References WGSBN Bulletin Volume 5, #1 https://www.wgsbn-iau.org/files/Bulletins/V005/WGSBNBull_V005_001.pdf WGSBN Bulletin International Astronomical Union 5 1 28 13 January 2025 13 January 2025 (164207) = 2004 GU9 https://www.minorplanetcenter.net/db_search/show_object?object_id=164207 Minor Planet Center 3 June 2024 https://iau.org/news/pressreleases/detail/iau2406/ Competition Announced to Name a Quasi-Moon 31 May 2024 IAU 3 June 2024 https://radiolab.org/moon-official-rules/ OFFICIAL RULES: Name a Quasi Moon! Radiolab 3 June 2024 Radiolab is partnering with the International Astronomical Union to launch a months-long global naming contest for one of Earth’s quasi-moons (asteroid 164207). https://www.space.com/the-universe/earth/strange-quasi-moon-of-earth-will-get-one-of-these-7-names Strange "quasi-moon" of Earth will get one of these 7 names Mike Wall Space.com 2 December 2024 13 January 2025 NEO Groups NASA/JPL Near-Earth Object Program Office http://neo.jpl.nasa.gov/neo/groups.html https://web.archive.org/web/20020202160655/http://neo.jpl.nasa.gov/neo/groups.html dead 2002-02-02 2012-06-04 Wajer Paweł Dynamical evolution of Earth's quasi-satellites: 2004 GU 9 and 2006 FV 35 October 2010 Icarus 209 2 488–493 10.1016/j.icarus.2010.05.012 2010Icar..209..488W Stahl Asa Earth's quasi-moons, minimoons, and ghost moons 21 May 2024 The Planetary Society https://www.planetary.org/articles/the-quasi-moons-of-earth 3 October 2025 2 October 2025 https://web.archive.org/web/20251002073229/https://www.planetary.org/articles/the-quasi-moons-of-earth live de la Fuente Marcos C. de la Fuente Marcos R. Asteroid 2014 OL 339: yet another Earth quasi-satellite 21 October 2014 Monthly Notices of the Royal Astronomical Society 445 3 2985–2994 10.1093/mnras/stu1978 free 1409.5588 2014MNRAS.445.2961D External links Dynamical evolution of Earth’s quasi-satellites: 2004 GU9 and 2006 FV35 by Wajer, P. 2010, Icarus, Volume 209, Issue 2, pp. 488–493. 164207 164207 2004GU9 164207 164207 164207 Cardea 164207 164207 164207 164207 164207 164207 20040413 Category:Horseshoe orbit