Image of the Trojan asteroids in front of and behind Jupiter along its orbital path. Also shown is the main asteroid belt between the orbits of Mars and Jupiter.

As originally defined, Trojan asteroids have a semi-major axis between 5.05 AU and 5.40 AU, and lie in elongated, curved regions around the two Lagrangian points 60° ahead and behind of Jupiter. The term is sometimes used to refer to minor bodies with similar relationships to other major bodies. Image File history File links Image of the main asteroid belt between the orbits of Mars and Jupiter. ... Image File history File links Image of the main asteroid belt between the orbits of Mars and Jupiter. ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ... Mars, with polar ice caps visible. ... In geometry, the term semi-major axis (also semimajor axis) is used to describe the dimensions of ellipses and hyperbolas. ... The astronomical unit (AU or au or a. ... The Lagrangian points, (also Lagrange point, L-point, or libration point) are the five positions in space where a small object can be stationary with respect to two larger objects (such as a satellite with respect to the Earth and Moon). ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ...

History

E. E. Barnard is now believed to have made the first observation of a Trojan asteroid, in 1904, but the significance of his observation was not noted at the time. It was believed to have been a sighting of the recently discovered Saturnian satellite Phoebe, which was only two arc-minutes away in the sky at the time, or possibly even a star. The identity of the point of light Barnard observed was not realised until an orbit was constructed for the Trojan (12126) 1999 RM₁₁, an object that was only (re)discovered in 1999. For failing to realise what he was looking at, Barnard's observation is now only a historical curiosity. Edward Emerson Barnard (December 16, 1857 – February 6, 1923) was an American astronomer. ... 1904 is a leap year starting on a Friday (link will take you to calendar). ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... For other meanings see Phoebe. ... The Pleiades star cluster A star is any massive gaseous body in outer space, just like the Sun. ... 1999 is a common year starting on Friday of the Common Era, and was designated the International Year of Older Persons by the United Nations. ...

In February 1906, the German astronomer Max Wolf discovered an asteroid at the L₄ Lagrangian point of the Sun–Jupiter system, and named it 588 Achilles, after the mythical Achilles, one of the heroes of Homer's Iliad. The oddity of its orbit was realized within a few months, and before long, many other asteroids were discovered at this point (and the other triangular Lagrange point of the Sun–Jupiter system). 1906 was a common year starting on Monday (see link for calendar). ... Maximilian Franz Joseph Cornelius Wolf (June 21, 1863 – October 3, 1932) was a German astronomer. ... An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... The Lagrangian points, (also Lagrange point, L-point, or libration point) are the five positions in space where a small object can be stationary with respect to two larger objects (such as a satellite with respect to the Earth and Moon). ... A sun is the star at the center of a planetary system. ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ... 588 Achilles is an asteroid discovered on February 22, 1906 by the German astronomer Max Wolf. ... For other uses, see Achilles (disambiguation). ... Bust of Homer in the British Museum For other uses, see Homer (disambiguation). ... The Iliad (Greek Ἰλιάς, Ilias) tells part of the story of the siege of the city of Ilium, i. ...

There are currently (July 2004) 1,679 known Trojan asteroids — 1,051 at L₄ and 628 at L₅. There are undoubtedly many others too small to be seen with current instruments. As of October 1999, 170 had been numbered; by July 2004, that number had grown to 877. The largest of the Trojans is 624 Hektor, measuring 370×195 km. 2004 is a leap year starting on Thursday of the Gregorian calendar. ... 1999 is a common year starting on Friday of the Common Era, and was designated the International Year of Older Persons by the United Nations. ... 2004 - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... 624 Hektor is the largest of the Jovian Trojan asteroids. ...

Nomenclature

Following Wolf's lead these asteroids were given names associated with the Iliad — in fact, those in the L₄ point are named after Greek heroes of the Iliad (the "Greek node" or "Achilles group"), and those at the L₅ point are named after the heroes of Troy (the "Trojan node"). Confusingly, the latter group are sometimes called Patroclean asteroids after the most prominent of those, even though Patroclus (the hero) was on the Greek side. However, 617 Patroclus (the asteroid) was the first discovered asteroid at the L₅ point, and was named before the Greece/Troy rule was devised. The Greek node also has one "misplaced" asteroid; 624 Hektor. ... A cup depicting Achilles bandaging Patroklos arm, by Sosias. ... 624 Hektor is the largest of the Jovian Trojan asteroids. ...

As the Iliad deals with the events of the Trojan War, the asteroids came to be collectively known as Trojan asteroids. Over time, this term has come to be more generally applied to any planetoidal body at the triangular Lagrangian point of any two bodies — besides Jupiter's Trojans, Mars and Neptune have one Trojan each, plus there are Trojan moons around Saturn (Telesto–Tethys–Calypso and Helene–Dione–Polydeuces). Strictly speaking, the term Trojan applies only to those in the L₄ and L₅ points of the Sun–Jupiter system. The Trojan War was a war waged, according to legend, against the city of Troy in Asia Minor by the armies of the Acheans, following the kidnapping (or elopement) of Helen of Sparta by Paris of Troy. ... Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ... Atmospheric characteristics Surface pressure ≫100 MPa Hydrogen - H2 80% ±3. ... A Trojan moon is a natural satellite of a planet occupying the L4 or L5 equilateral Lagrangian points of a primary-moon system. ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... Atmosphere none Telesto (te-les-toe, Greek Τελεστώ) is a moon of Saturn. ... Atmosphere none Tethys (tee-this or teth-is, Greek Τηθύς) is a moon of Saturn that was discovered by Giovanni Domenico Cassini in 1684. ... Atmosphere none Calypso (ka-lip-soe, Greek Καλυψώ) is a moon of Saturn. ... Helene (hel-e-nee, Greek ‘Ελένη) is a moon of Saturn. ... Atmosphere none Dione (dye-oe-nee, Greek Διώνη) is a moon of Saturn discovered by Giovanni Cassini in 1684. ... Atmosphere none Polydeuces (pol-ee-dew-seez, Greek Πολυδεύκης) is a natural satellite of Saturn that was discovered on images taken on October 21, 2004 by the Cassini imaging team, led by Carolyn C. Porco et al, and given the temporary designation S/2004 S 5. ...

See also

• List of Trojan asteroids (Greek camp)
• List of Trojan asteroids (Trojan camp)
• Pronunciation of Trojan asteroid names

This is a list of Trojan asteroids - asteroids that lie in elongated, curved regions around the two Lagrangian points 60° ahead and behind of Jupiter. ... This is a list of Trojan asteroids - asteroids that lie in elongated, curved regions around the two Lagrangian points 60° ahead and behind of Jupiter. ... Pronunciation of the Trojan asteroids Pronunciation key ...

External link

• Minor Planet Center's List of Trojan Minor Planets