The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo , discovered by German astronomer Karl Reinmuth in the 1930s. They are Earth-crossing asteroids that have an orbital semi-major axis greater than that of the Earth (a > 1 AU ) but perihelion distances less than the Earth's aphelion distance (q < 1.017 AU).[ 1] [ 2]
Common orbital subgroups of Near-Earth Objects (NEOs)
As of October 2024[update] , the number of known Apollo asteroids is 20,412, making the class the largest group of near-Earth objects (cf . the Aten , Amor and Atira asteroids),[ 3] of which 1,628 are numbered (asteroids are not numbered until they have been observed at two or more oppositions ), 79 are named, and 2,104 are identified as potentially hazardous asteroids .[ 4] [ 5]
The closer their semi-major axis is to Earth's, the less eccentricity is needed for the orbits to cross. The Chelyabinsk meteor , that exploded over the city of 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 .[ 6] [ 7]
The largest known Apollo asteroid is 1866 Sisyphus , with a diameter of about 8.5 km. Examples of known Apollo asteroids include:
Designation
Year
Discoverer/First observed (A)
Ref
2024 PT5
2024
ATLAS-SAAO
MPC
2019 SU3
2019
ATLAS-HKO
MPC
2016 WF9
2016
NEOWISE
MPC
(671294) 2014 JO25
2014
CSS
MPC
2013 FW13
2013
CSS
MPC
2013 RH74
2013
CSS
MPC
2011 MD
2011
LINEAR
MPC (B)
2011 EO40
2011
CSS–Mount Lemmon Survey
MPC
2010 AL30
2010
LINEAR
MPC
(529366) 2009 WM1
2009
CSS
MPC
2009 DD45
2009
Siding Spring Observatory, Australia
MPC
(386454) 2008 XM
2008
LINEAR
List
2008 TC3
2008
CSS
MPC
2008 FF5
2008
CSS–Mount Lemmon Survey
MPC
2007 VK184
2007
CSS
MPC
2007 TU24
2007
CSS
MPC
2007 WD5
2007
CSS
MPC
2007 OX
2007
CSS–Mount Lemmon Survey
MPC
(277810) 2006 FV35
2006
Spacewatch
List
(394130) 2006 HY51
2006
LINEAR
List
(292220) 2006 SU49
2006
Spacewatch
List
(308635) 2005 YU55
2005
R. S. McMillan, Steward Observatory, Kitt Peak, USA
List
2005 WY55
2005
Mount Lemmon Survey
MPC
2005 HC4
2005
LONEOS
MPC
(612901) 2004 XP14
2004
LINEAR
MPC
(374158) 2004 UL
2004
LINEAR
List
(357439) 2004 BL86
2004
LINEAR
List
(444004) 2004 AS1
2004
LINEAR
List
2003 RW11
2003
James Whitney Young
MPC
2003 BV35
2003
James Whitney Young
MPC
(89958) 2002 LY45
2002
LINEAR
List
(179806) 2002 TD66
2002
LINEAR
List
54509 YORP
2000
LINEAR
List
162173 Ryugu
1999
LINEAR
List
(137108) 1999 AN10
1999
LINEAR
List
101955 Bennu
1999
LINEAR (Bennu is the target of the OSIRIS-REx mission)
List
1998 KY26
1998
Spacewatch
MPC
(433953) 1997 XR2
1997
LINEAR
List
65803 Didymos
1996
Spacewatch
List
69230 Hermes
1937
Karl Reinmuth
List
(53319) 1999 JM8
1999
LINEAR
List
(52760) 1998 ML14
1998
LINEAR
List
(35396) 1997 XF11
1997
Spacewatch
List
25143 Itokawa
1998
LINEAR
List
(136617) 1994 CC
1994
Spacewatch
List
(175706) 1996 FG3
1996
R. H. McNaught, Siding Spring Observatory, Australia
List
6489 Golevka
1991
Eleanor F. Helin
List
4769 Castalia
1989
Eleanor F. Helin
List
4660 Nereus
1982
Eleanor F. Helin
List
4581 Asclepius
1989
Henry E. Holt , Norman G. Thomas
List
4486 Mithra
1987
Eric Elst , Vladimir Shkodrov
List
14827 Hypnos
1986
Carolyn S. Shoemaker , Eugene Merle Shoemaker
List
4197 Morpheus
1982
Eleanor F. Helin , Eugene Merle Shoemaker
List
4183 Cuno
1959
Cuno Hoffmeister
List
4179 Toutatis
1989
Christian Pollas
List
4015 Wilson–Harrington
1979
Eleanor F. Helin
List
3200 Phaethon
1983
Simon F. Green , John K.Davies / IRAS
List
2063 Bacchus
1977
Charles T. Kowal
List
1866 Sisyphus
1972
Paul Wild
List
1620 Geographos
1951
Albert George Wilson , Rudolph Minkowski
List
(29075) 1950 DA
1950
Carl A. Wirtanen
List
1566 Icarus
1949
Walter Baade
List
1685 Toro
1948
Carl A. Wirtanen
List
2101 Adonis
1936
Eugène Joseph Delporte
List
1862 Apollo
1932
Karl Reinmuth
List
(A) Discoverer :
A discoverer is determined by the 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[ 8]
(B) Classification :
2011 MD is classified as Amor, not Apollo asteroid by the MPC