ASTEROIDS : THE TROJANS

The Trojan asteroids are on the same orbit as Jupiter; they are either ahead of 60° on Jupiter (point L4) or delayed by 60 ° (point L5). These two points, named Lagrangian points correspond to areas of stability for objects on the same orbit as Jupiter.

Other planets also have Trojan asteroids on their orbit: Mars, Uranus, Neptune but also the Earth. Its "Trojans" are difficult to observe: we saw one at the point L4, 2010 TK7 having a size of 320 meters.

Some Jupiter Trojans

Some Jupiter Trojans ordered from the larger until the more recently discovered

Number	Name	Size en km	Distance from Sun en UA	Eccentricity	Inclination	Lagrangian point	Date of discovery
588	Achille	100	4.41/5.95	0.149	10°	L4	1906
617	Patroclus	110	4.50/5.95	0.139	22°	L5	1906
624	Hector	140	5.10/5.33	0.023	18°	L4	1907
659	Nestor	70	4.62/5.81	0.113	4°	L4	1908
884	Priam	75	4.53/5.79	0.122	9°	L5	1917
911	Agamemnon	176	4.88/5.59	0.068	22°	L4	1919
1143	Odyssey	115	4.77/5.74	0.092	3°	L4	1930
	...
-	2005 YB143	5	4.75/5.94	0.112	17°	L5	2005
-	2005 MU3	7	4.99/5.38	0.038	15°	L4	2005

There are 12190 Trojan asteroids of Jupiter suspected, observed until the present date (December 3, 2022), of which 7079 are numbered (that is to say confirmed). Curiously, they are not equally divided between those who are "ahead" and those "late". There are about two times more numerous in advance (at point L4) than late (at point L5). Also note that they remain at a constant distance of Jupiter, with an eccentricity and an inclination of their orbits much larger than those of Jupiter.

Trojans of Mars

Some Trojan asteroids of Mars are doubtful: it will be necessary to follow their orbits for several revolutions to be sure they are really at the Lagrangian points.

Number	Name	Size in km	Distance from the Sun in AU	Eccentricity	Inclination	Lagrangian point	Date of discovery
5261	Eureka	3	1.42/1.62	0.065	20°	L5	1990
101429	1998 VF31	1.5	1.37/1.67	0.101	31°	L5	1998
121514	1999 UJ7	2.0	1.46/1.58	0.039	17°	L4	1999
311999	2007 NS2	1.0	1.44/1.61	0.054	19°	L5	2007
-	2001 DH47	1.0	1.44/1.61	0.054	19°	L5	2001
-	2011 SC191	1.0	1.44/1.61	0.054	19°	L5	2011
-	2011 SL25	1.0	1.44/1.61	0.054	19°	L5	2011
-	2011 UN63	1.0	1.44/1.61	0.054	19°	L5	2011

The case of the Earth

We only know one asteroid which seems to be a Trojan Earth.

Number	Name	Size in km	Distance from Sun en UA	Eccentricity	Inclination	Lagrangian point	Date of discovery
-	2010 TK7	0.4	0.81/1.19	0.191	20.9°	L5	1990

The Troyan of Uranus

We only know one asteroid which seems to be a Trojan of Uranus.

Number	Name	Size in km	Distance to the Sun in AU	Eccentricity	Inclination	Lagrange point	Date of discovery
-	2011 QF 99	50	15/22	0,178	10.8°	L4	2011

Trojans of Neptune

We known 27 possible Neptune Trojans at point L4 and 4 at point L5, but their great distance from Earth makes their observation difficult and the orbital parameters remain uncertain. Below, nine of them.

Number	Name	Size in km	Distance from Sun in AU	Eccentricity	Inclination	Lagrangian point	Date of discovery
-	2001 QR322	80	29.3/31.1	0.029	1.3°	L4	2001
-	2004 KV18	60	24.5/35.7	0.185	13.6°	L5	2004
-	2004 UP10 (385571) Otrera	42	29.3/30.9	0.025	1.4°	L4	2004
-	2005 TN53	40	28.2/31.9	0.062	25.0°	L4	2005
-	2005 TO74 (385695)	50	28.5/31.6	0.051	5.3°	L4	2005
-	2006 RJ103	140	29.1/30.8	0.028	8.2°	L4	2006
-	2007 VL305	60	28.1/32.0	0.064	28.1°	L4	2007
-	2008 LC18	55	27.5/32.5	0.083	27.6°	L5	2008
-	2011 HM102	140	27.7/32.4	0.078	29.4°	L5	2011