View source for Apollo asteroid

{{Short description|Group of near-Earth asteroids}}
[[File:Neo orbit types.jpg|thumb|upright=2.4|Common orbital subgroups of [[Near-Earth Object]]s (NEOs)]]

The '''Apollo asteroids''' are a group of [[near-Earth asteroid]]s named after [[1862 Apollo]], discovered by German astronomer [[Karl Reinmuth]] in the 1930s. They are [[Earth-crosser asteroid|Earth-crossing asteroid]]s that have an orbital [[semimajor axis|semi-major axis]] greater than that of the Earth (a &gt; 1 [[Astronomical unit|AU]]) but [[perihelion]] distances less than the Earth's [[aphelion]] distance (q < 1.017 AU).<ref name="NEO-groups" /><ref name="Wolfram-Apollo" />

{{As of|2025|01}}, the number of known Apollo asteroids is 21,083, making the class the largest group of [[near-Earth object]]s (''cf''. the [[Aten asteroid|Aten]], [[Amor asteroid|Amor]] and [[Atira asteroid|Atira]] asteroids), of which 1,742 are [[Minor planet designation|numbered]] (asteroids are not numbered until they have been observed at two or more [[Opposition (planets)|oppositions]]), 81 are named, and 2,130 are identified as [[potentially hazardous asteroids]].<ref name="ssd-jpl">{{cite web |title=Small-Body Database Query |url=https://ssd.jpl.nasa.gov/tools/sbdb_query.html#! |website=Solar System Dynamics – Jet Propulsion Laboratory |publisher=NASA – California Institute of Technology |access-date=2025-01-17 |archive-date=2021-09-27 |archive-url=https://web.archive.org/web/20210927184129/https://ssd.jpl.nasa.gov/tools/sbdb_query.html#! |url-status=live }}</ref><ref>{{cite web |title=List of Apollo Minor Planets |url=https://minorplanetcenter.net/iau/lists/Apollos.html |website=IAU Minor Planet Center |publisher=Center for Astrophysics |access-date=2025-01-17 |archive-date=2024-05-29 |archive-url=https://web.archive.org/web/20240529003007/https://minorplanetcenter.net/iau/lists/Apollos.html |url-status=live }}</ref>

The closer their semi-major axis is to Earth's, the less [[Eccentricity (orbit)|eccentricity]] is needed for the [[orbit]]s to cross. The [[Chelyabinsk meteor]], that exploded over the city of [[Chelyabinsk#2013 meteor|Chelyabinsk]] in the southern Urals region of Russia on February 15, 2013, injuring an estimated 1,500 people with flying glass from broken windows, was an Apollo-class [[asteroid]].<ref name="USA-Today-Chelyabinsk" /><ref name="NewScientist-Chelyabinsk" />

Apollo asteroids are generally named after [[Greek deities]].<ref name="BAN315">{{Citation|url=https://badastronomy.beehiiv.com/p/ban-315-apophis-and-stargate|title=Apophis and Stargate|work=Bad Astronomy Newsletter|first=Phil|last=Phait|issue=315|date=19 April 2021|access-date=11 August 2025}}</ref>

== List ==
The largest known Apollo asteroid is [[1866 Sisyphus]], with a diameter of about 8.5&nbsp;km. Examples of known Apollo asteroids include:
<!-- Note: REVERSE NUMERICAL ORDER, to match authoritative external link below, for easy comparison -->

{| class="wikitable sortable"
|-
! [[Minor planet designation|Designation]]
! Year
! Discoverer/First observed&thinsp;<sup>(A)</sup>
! Ref
|-
| {{mpl|2025 PU}} || align=center |2025 || [[Zwicky Transient Facility]] || {{MPC|2025+PU}}
|-
|-
| {{mpl|2024 PT|5}} || align=center | 2024 || [[Asteroid Terrestrial-impact Last Alert System|ATLAS-SAAO]] || {{MPC|2024+PT5}}
|-
|-
| {{mpl|2019 SU|3}} || align=center | 2019 || [[Asteroid Terrestrial-impact Last Alert System|ATLAS-HKO]] || {{MPC|2019+SU3}}
|-
| {{mpl|2016 WF|9}} || align=center | 2016 || [[Wide-field Infrared Survey Explorer#NEOWISE (pre-hibernation)|NEOWISE]] || {{MPC|2016+WF9}}
|-
| {{mpl|(671294) 2014 JO|25}} || align=center | 2014 || [[Catalina Sky Survey|CSS]] || {{MPC|2014+JO25}}
|-
| {{mpl|2013 FW|13}} || align=center | 2013 || CSS || {{MPC|2013+FW13}}
|-
| {{mpl|2013 RH|74}} || align=center | 2013 || CSS || {{MPC|2013+RH74}}
|-
| {{mpl|2011 MD}} || align=center | 2011 || [[Lincoln Near-Earth Asteroid Research|LINEAR]] || {{MPC|2011+MD}}<sup>(B)</sup>
|-
| {{mpl|2011 EO|40}} || align=center | 2011 || CSS–[[Mount Lemmon Survey]] || {{MPC|2011+EO40}}
|-
| {{mpl|2010 AL|30}} || align=center | 2010 || LINEAR || {{MPC|2010+AL30}}
|-
| {{mpl|(529366) 2009 WM|1}} || align=center | 2009 || CSS || {{MPC|2009+WM1}}
|-
| {{mpl|2009 DD|45}} || align=center | 2009 || Siding Spring Observatory, Australia || {{MPC|2009+DD45}}
|-
| {{mpl|(386454) 2008 XM}} || align=center | 2008 || LINEAR || {{LoMP|386454|List}}
|-
| {{mpl|2008 TC|3}} || align=center | 2008 || CSS || {{MPC|2008+TC3}}
|-
| {{mpl|2008 FF|5}} || align=center | 2008 || CSS–[[Mount Lemmon Survey]] || {{MPC|2008+TC3}}
|-
| {{mpl|2007 VK|184}} || align=center | 2007 || [[Catalina Sky Survey|CSS]] || {{MPC|2007+VK184}}
|-
| {{mpl|2007 TU|24}} || align=center | 2007 || CSS || {{MPC|2007+TU24}}
|-
| {{mpl|2007 WD|5}} || align=center | 2007 || CSS || {{MPC|2007+WD5}}
|-
| {{mpl|2007 OX}} || align=center | 2007 || CSS–[[Mount Lemmon Survey]] || {{MPC|2007+OX}}
|-
| {{mpl|(277810) 2006 FV|35}} || align=center | 2006 || [[Spacewatch]] || {{LoMP|277810|List}}
|-
| {{mpl|(394130) 2006 HY|51}} || align=center | 2006 || LINEAR || {{LoMP|394130|List}}
|-
| {{mpl|(292220) 2006 SU|49}} || align=center | 2006 || Spacewatch || {{LoMP|292220|List}}
|-
| {{mpl|(308635) 2005 YU|55}} || align=center | 2005 || R. S. McMillan, Steward Observatory, Kitt Peak, USA || {{LoMP|308635|List}}
|-
| {{mpl|2005 WY|55}} || align=center | 2005 || [[Mount Lemmon Survey]] || {{MPC|2005+WY55}}
|-
| {{mpl|2005 HC|4}} || align=center | 2005 || [[LONEOS]] || {{MPC|2005+HC4}}
|-
| {{mpl|(612901) 2004 XP|14}} || align=center | 2004 || LINEAR || {{MPC|2004+XP14}}
|-
| {{mpl|(374158) 2004 UL}} || align=center | 2004 || LINEAR || {{LoMP|374158|List}}
|-
| {{mpl|(357439) 2004 BL|86}} || align=center | 2004 || LINEAR || {{LoMP|357439|List}}
|-
| {{mpl|(444004) 2004 AS|1}} || align=center | 2004 || LINEAR || {{LoMP|444004|List}}
|-
| {{mpl|2003 RW|11}} || align=center | 2003 || [[James Whitney Young]] || {{MPC|2003+RW11}}
|-
| {{mpl|2003 BV|35}} || align=center | 2003 || James Whitney Young || {{MPC|2003+BV35}}
|-
| {{mpl|(89958) 2002 LY|45}} || align=center | 2002 || LINEAR || {{LoMP|89958|List}}
|-
| {{mpl|(179806) 2002 TD|66}} || align=center | 2002 || LINEAR || {{LoMP|179806|List}}
|-
| [[54509 YORP]] || align=center | 2000 || [[Lincoln Near-Earth Asteroid Research|LINEAR]] || {{LoMP|54509|List}}
|-
| [[162173 Ryugu]] || align=center | 1999 ||[[Lincoln Near-Earth Asteroid Research|LINEAR]] || {{LoMP|162173|List}}
|-
| {{mpl|(137108) 1999 AN|10}} || align=center | 1999 || [[Lincoln Near-Earth Asteroid Research|LINEAR]] || {{LoMP|137108|List}}
|-
| [[101955 Bennu]] || align=center | 1999 || LINEAR (Bennu is the target of the [[OSIRIS-REx]] mission) || {{LoMP|101955|List}}
|-
| {{mpl|1998 KY|26}} || align=center | 1998 || Spacewatch || {{MPC|1998+KY26}}
|-
| {{mpl|(433953) 1997 XR|2}} || align=center | 1997 || [[Lincoln Near-Earth Asteroid Research|LINEAR]] || {{LoMP|433953|List}}
|-
| [[65803 Didymos]] || align=center | 1996 || [[Spacewatch]] || {{LoMP|65803|List}}
|-
| [[69230 Hermes]] || align=center | 1937 || [[Karl Reinmuth]] || {{LoMP|69230|List}}
|-
| {{mpl|(53319) 1999 JM|8}} || align=center | 1999 || LINEAR || {{LoMP|53319|List}}
|-
| {{mpl|(52760) 1998 ML|14}} || align=center | 1998 || LINEAR || {{LoMP|52760|List}}
|-
| {{mpl|(35396) 1997 XF|11}} || align=center | 1997 || Spacewatch || {{LoMP|35396|List}}
|-
| [[25143 Itokawa]] || align=center | 1998 || LINEAR || {{LoMP|25143|List}}
|-
| [[(136617) 1994 CC]] || align=center | 1994 || [[Spacewatch]] || {{LoMP|136617|List}}
|-
| {{mpl|(175706) 1996 FG|3}} || align=center | 1996 || R. H. McNaught, Siding Spring Observatory, Australia || {{LoMP|175706|List}}
|-
| [[6489 Golevka]] || align=center | 1991 || [[Eleanor F. Helin]] || {{LoMP|6489|List}}
|-
| [[4769 Castalia]] || align=center | 1989 || Eleanor F. Helin || {{LoMP|4769|List}}
|-
| [[4660 Nereus]] || align=center | 1982 || Eleanor F. Helin || {{LoMP|4660|List}}
|-
| [[4581 Asclepius]] || align=center | 1989 || [[Henry E. Holt]], [[Norman G. Thomas]] || {{LoMP|4581|List}}
|-
| [[4486 Mithra]] || align=center | 1987 || [[Eric Elst]], [[Vladimir Shkodrov]] || {{LoMP|4486|List}}
|-
| [[14827 Hypnos]] || align=center | 1986 || [[Carolyn S. Shoemaker]], [[Eugene Merle Shoemaker]] || {{LoMP|14827|List}}
|-
| [[4197 Morpheus]] || align=center | 1982 || [[Eleanor F. Helin]], [[Eugene Merle Shoemaker]] || {{LoMP|4197|List}}
|-
| [[4183 Cuno]] || align=center | 1959 || [[Cuno Hoffmeister]] || {{LoMP|4183|List}}
|-
| [[4179 Toutatis]] || align=center | 1989 || [[Christian Pollas]] || {{LoMP|4179|List}}
|-
| [[4015 Wilson–Harrington]] &nbsp; || align=center | 1979 || [[Eleanor F. Helin]] || {{LoMP|4015|List}}
|-
| [[3200 Phaethon]] || align=center | 1983 || [[Simon F. Green]], [[John K. Davies (astronomer)|John K.Davies]] / [[IRAS]] || {{LoMP|3200|List}}
|-
| [[2063 Bacchus]] || align=center | 1977 || [[Charles T. Kowal]] || {{LoMP|2063|List}}
|-
| [[1866 Sisyphus]] || align=center | 1972 || [[Paul Wild (Swiss astronomer)|Paul Wild]] || {{LoMP|1866|List}}
|-
| [[1620 Geographos]] || align=center | 1951 || [[Albert George Wilson]], [[Rudolph Minkowski]] || {{LoMP|1620|List}}
|-
| [[(29075) 1950 DA]] || align=center | 1950 || [[Carl A. Wirtanen]] || {{LoMP|29075|List}}
|-
| [[1566 Icarus]] || align=center | 1949 || [[Walter Baade]] || {{LoMP|1566|List}}
|-
| [[1685 Toro]] || align=center | 1948 || [[Carl A. Wirtanen]] || {{LoMP|1685|List}}
|-
| [[2101 Adonis]] || align=center | 1936 || [[Eugène Joseph Delporte]] || {{LoMP|2101|List}}
|-
| [[1862 Apollo]] || align=center | 1932 || [[Karl Reinmuth]] || {{LoMP|1862|List}}
|-
! colspan=4 style="font-size: 0.85em; font-weight: normal; text-align: left; padding: 6px;" |<sup>(A)</sup>&thinsp;'''Discoverer''':<br />
: A discoverer is determined by the [[Minor Planet Center|MPC]] when the object is numbered. For unnumbered bodies, the table gives the "first observer".
: LINEAR: [[Lincoln Near-Earth Asteroid Research]]
: CSS : [[Catalina Sky Survey]]
: [[Spacewatch]], on Kitt Peak, near Tucson, Arizona<ref>{{citation |url=http://spacewatch.lpl.arizona.edu/ |title=The Spacewatch Project |publisher=Arizona Board of Regents |year=2010 |access-date=2015-08-16 |archive-date=2017-07-18 |archive-url=https://web.archive.org/web/20170718190912/http://spacewatch.lpl.arizona.edu/ |url-status=live }}</ref>
<sup>(B)</sup>&thinsp;'''Classification''':<br />
: [[2011 MD]] is classified as Amor, not Apollo asteroid by the MPC
|}

== See also ==
* [[Alinda group]]
* [[Amor asteroid]]
* [[:Category:Apollo asteroids|Apollo asteroids (category)]]
* [[Apollo asteroid records]]
* [[Aten asteroid]]
* [[List of minor planets]]
*[[2020 PP1]]

== References ==
<references>
<ref name="NEO-groups">{{cite web
  |title      = Near-Earth Object Groups
  |publisher  = JPL – NASA
  |url        = http://neo.jpl.nasa.gov/neo/groups.html
  |archive-url = https://web.archive.org/web/20020202160655/http://neo.jpl.nasa.gov/neo/groups.html
  |url-status = dead
  |archive-date = 2 February 2002
  |access-date= 11 November 2016}}</ref>

<ref name="Wolfram-Apollo">{{cite web |last       = Weisstein |first       = Eric |title       = Apollo Asteroid |publisher       = Wolfram Research |url       = http://scienceworld.wolfram.com/astronomy/ApolloAsteroid.html |access-date       = 27 February 2013 |archive-date       = 28 January 2016 |archive-url       = https://web.archive.org/web/20160128104457/http://scienceworld.wolfram.com/astronomy/ApolloAsteroid.html |url-status       = live }}</ref>

<ref name="USA-Today-Chelyabinsk">{{cite web
 |first        = Matt
 |last         = Cantor
 |title        = Scientists figure out Russia meteor's origin
 |work         = USA Today
 |date         = 26 February 2013
 |url          = https://www.usatoday.com/story/tech/2013/02/26/meteor-russia-apollo-space/1948673/
 |access-date  = 11 November 2016
 |archive-date = 20 April 2019
 |archive-url  = https://web.archive.org/web/20190420144548/https://www.usatoday.com/story/tech/2013/02/26/meteor-russia-apollo-space/1948673/
 |url-status   = live
}}</ref>

<ref name="NewScientist-Chelyabinsk">{{cite web
 |author       = Jacob Aron
 |title        = Russian meteor traced to Apollo asteroid family
 |work         = New Scientist
 |date         = 26 February 2013
 |url          = https://www.newscientist.com/article/dn23213-russian-meteor-traced-to-apollo-asteroid-family/
 |access-date  = 11 November 2016
 |archive-date = 13 July 2024
 |archive-url  = https://web.archive.org/web/20240713095516/https://www.newscientist.com/article/dn23213-russian-meteor-traced-to-apollo-asteroid-family/
 |url-status   = live
}}</ref>
</references> <!-- end of reflist -->

== External links ==
* [http://www.minorplanetcenter.org/iau/lists/Apollos.html List of Apollo minor planets] {{Webarchive|url=https://web.archive.org/web/20141204222902/http://www.minorplanetcenter.org/iau/lists/Apollos.html |date=2014-12-04 }}

{{Asteroids}}
{{Small Solar System bodies}}

[[Category:Apollo asteroids| ]]
[[Category:Lists of asteroids|Apollo]]