List of objects at Lagrangian points

This is a list of known objects which have been, are or are planned to occupy any of the five Lagrangian points of two-body systems in space.

Sun-Earth Lagrangian points

L₁

L₁ is the Lagrangian point located approximately 1,500,000 km towards the Sun away from the Earth.

Past probes

*International Cometary Explorer, formerly the International Sun-Earth Explorer 3 (ISEE-3), diverted out of L₁ in 1983 for a comet rendezvous mission. Currently in solar orbit, it may be captured in 2014 when it next approaches Earth.
*NASA's Genesis probe collected solar wind samples at L1 from December 3, 2001 to April 1, 2004, when it returned to Earth.

Present probes

*GGS WIND
*The Solar and Heliospheric Observatory (SOHO)
*The Advanced Composition Explorer (ACE)

Planned probes

*LISA Pathfinder
*Kuafu

Cancelled probes

*The Triana satellite, designed to monitor global warming.

L₂

L₂ is the Lagrangian point located approximately 1,500,000 km away from the Earth in the direction opposite the Sun.

Past probes

*GEOTAIL

Present probes

*Wilkinson Microwave Anisotropy Probe (WMAP)

Planned probes

*The joint NASA, ESA and CSA James Webb Space Telescope (JWST), formerly known as the Next Generation Space Telescope (NGST)
*The ESA Herschel Space Observatory
*The ESA Planck Surveyor
*The ESA Gaia probe
*The NASA Terrestrial Planet Finder mission (may be placed in an Earth-trailing orbit instead)
*The ESA Darwin mission
*The NASA Advanced Technology Large-Aperture Space Telescope, that will replace both the Hubble Space Telescope and JWST.

Cancelled probes

*The ESA Eddington mission

L₃

L₃ is the Lagrangian point located on the side of the Sun opposite the Earth, slightly outside the Earth's orbit.
* There are no known objects in this orbital location.

L₄

L₄ is the Lagrangian point located close to the Earth's orbit 60° ahead of the Earth.

*Dust clouds ref|baez_math_ucr_edu

L₅

L₅ is the Lagrangian point located close to the Earth's orbit 60° behind the Earth.

*Dust clouds
*Spitzer is in an earth-trailing heliocentric orbit drifting away circa 0.1 AU per year. In circa 2013-15 it will pass L₅ in its orbit.

Earth-Moon Lagrangian points

L₂

*future location of TDRS-derived satellites to facilitate direct communications between Earth and far side of the Moon.Fact|date=April 2007

L₄

*possible Kordylewski clouds

L₅

*possible Kordylewski clouds

L₄ and L₅

*future location of TDRS-style communication satellites to support L₂ satellite

Cancelled objects

In his book "" Dr. Gerard O'Neill proposed the establishment of gigantic "Space Islands" in L₅. The inhabitants of the L5 Society should convert Lunar material to huge solar power satellites.

un-Mars Lagrangian points

Asteroids in the L₄ and L₅ Mars-Sun Lagrangian points are sometimes called "Mars Trojan asteroids", but "Trojan asteroid", as originally defined, is a term for asteroids in the L₄ and L₅ Jupiter-Sun Lagrangian points.

L₄

*mpl|1999 UJ|7

L₅

*5261 Eureka
*mpl|1998 VF|31, mpl|2001 DH|47, mpl|2001 FG|24, mpl|2001 FR|127 (not confirmed as true Lagrangian asteroids)

un-Jupiter Lagrangian points

Asteroids in the L₄ and L₅ Jupiter-Sun Lagrangian points are known as "Jupiter Trojan asteroids" or simply "Trojan asteroids".

L₄

*Trojan asteroids, Greek camp

L₅

*Trojan asteroids, Trojan camp

=Saturn-Tethys Lagrangian points=

L₄

*Telesto

L₅

*Calypso

=Saturn-Dione Lagrangian points=

L₄

*Helene

L₅

*Polydeuces

un-Neptune Lagrangian points

Asteroids in the L₄ and L₅ Neptune-Sun Lagrangian points are sometimes called "Neptune Trojan asteroids", but "Trojan asteroid", as originally defined, is a term for asteroids in the L₄ and L₅ Jupiter-Sun Lagrangian points.

L₄

*mpl|2001 QR|322
*mpl|2004 UP|10
*mpl|2005 TN|53
*mpl|2005 TO|74
*mpl|2006 RJ|103
*mpl|2007 VL|305Source: Minor Planet Center [http://cfa-www.harvard.edu/iau/lists/NeptuneTrojans.html]

ee also

*Trojan points
*Trojan asteroid
*Trojan moon
*Trojan planet

References

# [http://math.ucr.edu/home/baez/lagrange.html John Baez' Lagrange Points page]