List of objects at Lagrangian points
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This is a list of known objects which occupy, have occupied, or are planned to occupy any of the five
Lagrange point In celestial mechanics, the Lagrange points (; also Lagrangian points or libration points) are points of equilibrium for small-mass objects under the gravitational influence of two massive orbiting bodies. Mathematically, this involves t ...
s of two-body systems in space.


Sun–Earth Lagrange points


Sun–Earth L1

is the Lagrange point located approximately 1.5 million kilometers from Earth towards the Sun.


Past probes

* International Cometary Explorer, formerly the International Sun–Earth Explorer 3 (ISEE-3), diverted out of in 1983 for a comet rendezvous mission. Currently in
heliocentric orbit A heliocentric orbit (also called circumsolar orbit) is an orbit around the barycenter of the Solar System, which is usually located within or very near the surface of the Sun. All planets, comets, and asteroids in the Solar System, and the Sun ...
. The Sun–Earth L1 is also the point to which the Reboot ISEE-3 mission was attempting to return the craft as the first phase of a recovery mission (as of September 25, 2014 all efforts have failed and contact was lost). *NASA's Genesis probe collected solar wind samples at from December 3, 2001, to April 1, 2004, when it returned the sample capsule to Earth. It returned briefly in late 2004 before being pushed into heliocentric orbit in early 2005. * LISA Pathfinder (LPF) was launched on 3 December 2015, and arrived at on 22 January 2016, where, among other experiments, it tested the technology needed by (e)LISA to detect gravitational waves. LISA Pathfinder used an instrument consisting of two small gold alloy cubes. *The Chang'e 5 orbiter (during extended mission. After ferrying lunar samples back to Earth in 2020, the transport module was sent to where it is permanently stationed to conduct limited Earth-Sun observations.)


Present probes

* The Solar and Heliospheric Observatory (SOHO) in a halo orbit around L1 ** Mission: Investigation of the outer layer of the Sun, making observations of solar wind and associated phenomena in the vicinity of L1, probing the interior structure of the Sun. ** Launched: 2 December 1995 ** Arrival: Operational orbit in May 1996 **Institution: ESA * The Advanced Composition Explorer (ACE) in a Lissajous orbit *
WIND Wind is the natural movement of atmosphere of Earth, air or other gases relative to a planetary surface, planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heatin ...
(At since 2004) * The Deep Space Climate Observatory (DSCOVR), designed to image the sunlit Earth in 10 wavelengths (EPIC) and monitor total reflected radiation (NISTAR). Launched on 11 February 2015, began orbiting L1 on 8 June 2015 to study the
solar wind The solar wind is a stream of charged particles released from the Sun's outermost atmospheric layer, the Stellar corona, corona. This Plasma (physics), plasma mostly consists of electrons, protons and alpha particles with kinetic energy betwee ...
and its effects on Earth. DSCOVR is unofficially known as GORESAT, because it carries a camera always oriented to Earth and capturing full-frame photos of the planet similar to the Blue Marble. This concept was proposed by then-Vice President of the United States
Al Gore Albert Arnold Gore Jr. (born March 31, 1948) is an American former politician, businessman, and environmentalist who served as the 45th vice president of the United States from 1993 to 2001 under President Bill Clinton. He previously served as ...
in 1998 and was a centerpiece in his 2006 film ''
An Inconvenient Truth ''An Inconvenient Truth'' is a 2006 American documentary film directed by Davis Guggenheim about former vice president of the United States Al Gore's campaign to educate people about Climate change, global warming. The film features a slide s ...
''. * Aditya-L1 was successfully launched on 2 September 2023 and entered the halo orbit around the lagrange point on 6 January 2024. It's a
Solar observation Solar observation is the scientific endeavor of studying the Sun and its behavior and relation to the Earth and the remainder of the Solar System. Deliberate solar observation began thousands of years ago. That initial era of direct observation g ...
mission by
ISRO The Indian Space Research Organisation (ISRO ) is India's national space agency, headquartered in Bengaluru, Karnataka. It serves as the principal research and development arm of the Department of Space (DoS), overseen by the Prime Minister o ...
. It will study solar atmosphere, solar magnetic storms, and their impact on the environment around the Earth.


Planned probes

* Interstellar Mapping and Acceleration Probe slated for launch in late 2025 *
NEO Surveyor NEO Surveyor, formerly called Near-Earth Object Camera (NEOCam), then NEO Surveillance Mission, is a planned space-based infrared telescope designed to Astronomical survey, survey the Solar System for potentially hazardous object, potentially h ...
* SWFO-L1 *
Vigil A vigil, from the Latin meaning 'wakefulness' ( Greek: , or ), is a period of purposeful sleeplessness, an occasion for devotional watching, or an observance. The Italian word has become generalized in this sense and means 'eve' (as in "on t ...
(ESA). One spacecraft in L1 and one in L5.


Sun–Earth L2

is the Lagrange point located approximately 1.5 million kilometers from Earth in the direction opposite the Sun. Spacecraft at the Sun–Earth L2 point are in a Lissajous orbit until decommissioned, when they are sent into a
heliocentric Heliocentrism (also known as the heliocentric model) is a Superseded theories in science#Astronomy and cosmology, superseded astronomical model in which the Earth and Solar System, planets orbit around the Sun at the center of the universe. His ...
graveyard orbit A graveyard orbit, also called a junk orbit or disposal orbit, is an Orbit (physics), orbit that lies away from common operational orbits. One significant graveyard orbit is a supersynchronous orbit well beyond geosynchronous orbit. Some satellit ...
.


Past probes

*2001 – 2010: NASA's
Wilkinson Microwave Anisotropy Probe The Wilkinson Microwave Anisotropy Probe (WMAP), originally known as the Microwave Anisotropy Probe (MAP and Explorer 80), was a NASA spacecraft operating from 2001 to 2010 which measured temperature differences across the sky in the cosmic mic ...
(WMAP) observed the cosmic microwave background. It was moved to a heliocentric orbit to avoid posing a hazard to future missions. *2003 – 2004: NASA's
WIND Wind is the natural movement of atmosphere of Earth, air or other gases relative to a planetary surface, planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heatin ...
. The spacecraft then went to Earth orbit, before heading to . *2009 – 2013: The ESA
Herschel Space Observatory The Herschel Space Observatory was a space observatory built and operated by the European Space Agency (ESA). It was active from 2009 to 2013, and was the largest infrared telescope ever launched until the launch of the James Webb Space Telesco ...
exhausted its supply of liquid helium and was moved from the Lagrangian point in June 2013. *2009 – 2013: At the end of its mission ESA's '' Planck'' spacecraft was put into a heliocentric orbit and passivated to prevent it from endangering any future missions. *2011 – 2012: CNSA's
Chang'e 2 Chang'e 2 (; ) is a Chinese uncrewed lunar probe that was launched on 1 October 2010. It was a follow-up to the Chang'e 1 lunar probe, which was launched in 2007. Chang'e 2 was part of the first phase of the Chinese Lunar Exploration Program, ...
. Chang'e 2 was then placed onto a heliocentric orbit that took it past the near-Earth asteroid 4179 Toutatis. * The CNSA
Chang'e 6 Chang'e 6 () was the sixth robotic lunar exploration mission by the China National Space Administration (CNSA) and the second CNSA lunar sample-return mission. Like its predecessors in the Chinese Lunar Exploration Program, the spacecraft is ...
orbiter * 2013 – 2025: The ESA Gaia mission’s thrusters moved the spacecraft away from L2 on 27 March 2025 and into a stable retirement orbit around the Sun that will minimise the chance that it comes within 10 million km Earth for at least the next century.


Present probes

* The joint Russian-German high-energy astrophysics observatory
Spektr-RG Spektr-RG ( Russian: Спектр-РГ, ''Spectrum'' + '' Röntgen'' + ''Gamma''; also called Spectrum-X-Gamma, SRG, SXG) is a Russian–German high-energy astrophysics space observatory which was launched on 13 July 2019. It follows on from t ...
* The joint
NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
, ESA and CSA
James Webb Space Telescope The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, Lis ...
(JWST) * The ESA
Euclid Euclid (; ; BC) was an ancient Greek mathematician active as a geometer and logician. Considered the "father of geometry", he is chiefly known for the '' Elements'' treatise, which established the foundations of geometry that largely domina ...
mission


Planned probes

*The NASA
Nancy Grace Roman Space Telescope The Nancy Grace Roman Space Telescope (shortened as the Roman Space Telescope, Roman, or RST) is a NASA infrared space telescope in development and scheduled to launch to a Sun–Earth L2 orbit by May 2027. It is named after former NASA Chie ...
(WFIRST) *The ESA
PLATO Plato ( ; Greek language, Greek: , ; born  BC, died 348/347 BC) was an ancient Greek philosopher of the Classical Greece, Classical period who is considered a foundational thinker in Western philosophy and an innovator of the writte ...
mission, which will find and characterize rocky exoplanets. *The JAXA LiteBIRD mission. *The ESA Advanced Telescope for High ENergy Astrophysics (ATHENA) *The ESA ARIEL mission, which will observe the atmospheres of exoplanets. *The joint ESA-JAXA Comet Interceptor *The NASA Large Ultraviolet Optical Infrared Surveyor (LUVOIR) which would replace the
Hubble Space Telescope The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...
.


Cancelled probes

*The ESA Eddington mission *The NASA Terrestrial Planet Finder mission (may be placed in an Earth-trailing orbit instead)


Sun–Earth L3

is the Sun–Earth Lagrange point located on the side of the Sun opposite Earth, slightly outside the Earth's orbit. Direct communication with spacecraft in this position is blocked by the Sun. * There are no known objects in this orbital location.


Sun–Earth L4

is the Sun–Earth Lagrange point located close to the Earth's orbit 60° ahead of Earth. * Asteroid is the first discovered tadpole orbit companion to Earth, orbiting ; like Earth, its mean distance to the Sun is about one
astronomical unit The astronomical unit (symbol: au or AU) is a unit of length defined to be exactly equal to . Historically, the astronomical unit was conceived as the average Earth-Sun distance (the average of Earth's aphelion and perihelion), before its m ...
. * Asteroid is the second Earth trojan, confirmed in November 2021, oscillating around in a tadpole orbit and expected to remain there for at least 4000 years, until destabilized by Venus. *
STEREO Stereophonic sound, commonly shortened to stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This is usually achieved by using two independent audio channels through a configurat ...
A (Solar TErrestrial RElations Observatory – Ahead) made its closest pass to in September 2009, on its orbit around the Sun, slightly faster than Earth.NASA - Join STEREO and Explore Gravitational "Parking Lots" That May Hold Secret of Moon's Origin
/ref> *
OSIRIS-REx OSIRIS-REx was a NASA asteroid-study and sample-return mission that visited and collected samples from 101955 Bennu, a C-type asteroid, carbonaceous near-Earth object, near-Earth asteroid. The material, returned in September 2023, is expected ...
passed near the L4 point and performed a survey for asteroids between 9 and 20 February 2017.


Sun–Earth L5

, or Earth-trailing orbit, is the Sun–Earth Lagrange point located close to the Earth's orbit 60° behind Earth. *Asteroid , in a horseshoe companion orbit with Earth, is currently proximal to but at a high inclination. * STEREO B (Solar TErrestrial RElations Observatory – Behind) made its closest pass to in October 2009, on its orbit around the Sun, slightly slower than Earth. *The
Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003, that was deactivated when operations ended on 30 January 2020. Spitzer was the third space telescope dedicate ...
is in an Earth-trailing heliocentric orbit drifting away c. 0.1 AU per year. In c. 2013–15 it has passed in its orbit. *'' Hayabusa2'' passed near during the spring of 2017, and imaged the surrounding area to search for
Earth trojan An Earth trojan is an asteroid that orbits the Sun in the vicinity of the Earth–Sun Lagrange points (leading 60°) or (trailing 60°), thus having an orbit similar to Earth's. Only two Earth trojans have so far been discovered. The name "tr ...
s on 18 April 2018.


Proposed

*
Vigil A vigil, from the Latin meaning 'wakefulness' ( Greek: , or ), is a period of purposeful sleeplessness, an occasion for devotional watching, or an observance. The Italian word has become generalized in this sense and means 'eve' (as in "on t ...
(ESA). One spacecraft in L5.


Earth–Moon Lagrange points


Earth–Moon L2

*
THEMIS In Greek mythology and religion, Themis (; ) is the goddess and personification of justice, divine order, law, and custom. She is one of the twelve Titan children of Gaia and Uranus, and the second wife of Zeus. She is associated with oracles a ...
* Chang'e 5-T1 * Queqiao relay satellite * EQUULEUS nanosat.


Earth–Moon L4 and L5

* Kordylewski clouds *Future location of TDRS-style communication satellites to support satellite and further regions on the Moon.


Past probes

* Hiten was the first spacecraft to demonstrate a low energy trajectory, passing by and to achieve lunar orbit at a very low fuel expense, compared to usual orbital techniques. Hiten did not find any conclusive increase in dust density at Lagrange points.


Proposed objects

* Exploration Gateway Platform * In his 1976 book '' The High Frontier: Human Colonies in Space'' Dr. Gerard O'Neill proposed the establishment of gigantic ''Space Islands'' in . The inhabitants of the L5 Society should convert lunar material to huge solar power satellites. Many works of fiction, most notably the ''
Gundam is a Japanese military science fiction media franchise. Created by Yoshiyuki Tomino and Sunrise (now Bandai Namco Filmworks), the franchise features giant robots, or mecha, with the name "Gundam". The franchise began on April 7, 1979, with ...
'' series, involve colonies at these locations.


Sun–Venus Lagrange points


L4

*


Sun–Mars Lagrange points

Asteroids in the and Sun–Mars Lagrangian points are sometimes called ''
Mars trojan The Mars trojans are a group of trojan objects that share the orbit of the planet Mars around the Sun. They can be found around the two Lagrangian points 60° ahead of and behind Mars. The origin of the Mars trojans is not well understood. One t ...
s,'' with a lower-case t, as "Trojan asteroid" was originally defined as a term for Lagrangian asteroids of Jupiter. They may also be called ''Mars Lagrangian asteroids.''


L4

*


L5

* 5261 Eureka * * *, , (not confirmed as true Lagrangian asteroids) Source: Minor Planet Cente


Sun–Ceres Lagrange points

* 1372 Haremari * *


Sun–Jupiter Lagrange points

Asteroids in the and Sun–Jupiter Lagrangian points are known as ''Jupiter Trojan asteroids'' or simply ''
Trojan asteroid In astronomy, a trojan is a small celestial body (mostly asteroids) that shares the orbit of a larger body, remaining in a stable orbit approximately 60° ahead of or behind the main body near one of its Lagrangian points and . Trojans can shar ...
s''.


L4

* Trojan asteroids, Greek camp


L5

* Trojan asteroids, Trojan camp


L4 and L5

* Lucy (spacecraft), L4 in 2027, L5 in 2033


Saturn–Tethys Lagrange points


L4

* Telesto


L5

* Calypso


Saturn–Dione Lagrange points


L4

* Helene


L5

* Polydeuces, follows a "tadpole" orbit around L5


Sun–Uranus Lagrange points


L3

* 83982 Crantor, follows a horseshoe orbit around L3


L4

* *


Sun–Neptune Lagrange points

Minor planets in the and Sun–Neptune Lagrangian points are called
Neptune trojan Neptune trojans are bodies that orbit the Sun near one of the stable Lagrangian points of Neptune, similar to the trojans of other planets. They therefore have approximately the same orbital period as Neptune and follow roughly the same orbita ...
s, with a lower-case ''t'', as "Trojan asteroid" was originally defined as a term for Lagrangian asteroids of Jupiter. ''Data from:'' Minor Planet Cente


L4

* 385571 Otrera * 385695 Clete * * * *


L5

* * *


Tables of missions

Color key:


Future and proposed missions


See also

*
Trojan (celestial body) In astronomy, a trojan is a small celestial body (mostly asteroids) that shares the orbit of a larger body, remaining in a stable orbit approximately 60° ahead of or behind the main body near one of its Lagrangian points and . Trojans can shar ...
*
Co-orbital configuration In astronomy, a co-orbital configuration is a configuration of two or more astronomical objects (such as asteroids, moons, or planets) orbiting at the same, or very similar, distance from their primary; i.e., they are in a 1:1 mean-motion resonanc ...


Footnotes

{{DEFAULTSORT:Objects At Lagrangian Points Trojans (astronomy) Outer space lists *