Among the 1600 known asteroids, a group of fifteen minor planets, the so-called "Trojans", stands out for its remarkable movement: Achilles, Patroclus, Hector, Nestor, Priam, Agamemnon, etc. Every "Trojan" is spinning around the Sun so that it, Jupiter and the Sun are at any time located at the vertices of an equilateral triangle. "Trojans" are kind of fellow travelers of Jupiter, who accompany it, staying at a great distance: some are 60 degrees ahead of Jupiter, others are just behind him and all complete the revolution near the Sun at the same time.

Among the 1600 known asteroids, a group of fifteen minor planets, the so-called Trojans, stands out for its remarkable movement

The equilibrium of this planetary triangle is stable: if the asteroid "Trojan" had come out of its position, the gravitational force would have returned it to the abandoned place.

Long before the discovery of the Trojans, a similar case of mobile equilibrium of three attracting bodies was envisaged in purely theoretical studies of the French mathematician Lagrange. He considered this case as a curious mathematical problem and believed that hardly anywhere in the universe such relationships are real. Diligent search for asteroids led to the fact that for the theoretical case of Lagrange there was found a real illustration within our own planetary system. It clearly shows how important the development of astronomy has for the careful study of the numerous celestial bodies that are united under the name of small planets.

In addition to the "Trojans" of Jupiter, the Trojans of Earth, Mars, Uranus and Neptune are known. In 2010, the Earth discovered the first Trojan asteroid - 2010 TK7 - a small object, with a diameter of 300 meters. In addition, five Martian asteroids and nine Neptune asteroids are currently known.

Trojan asteroids Uranus is a group of asteroids moving around the Sun along the orbit of Uranus and revolving around one of the two Lagrangian points of the Uranus-Sun system. Initially, it was believed that Uranus and Saturn can not have Trojans, since Jupiter long ago had to draw to itself all the celestial bodies in these areas. In 2013, it was announced that the first Trojan asteroid - 2011 QF99, a small object with a diameter of 60 km was discovered from Uranus.