Sun–Earth L2
E59342
Sun–Earth L2 is a gravitationally stable point in space located beyond Earth's orbit where the combined gravity of the Sun and Earth allows spacecraft, such as the James Webb Space Telescope, to maintain a relatively constant position with minimal fuel use.
All labels observed (7)
How this entity was disambiguated
This entity first appeared as the object of triple T476158 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Sun–Earth L2 Context triple: [James Webb Space Telescope, librationPoint, Sun–Earth L2]
-
A.
Deep Space Climate Observatory
The Deep Space Climate Observatory (DSCOVR) is a NOAA and NASA satellite positioned at the Sun–Earth L1 Lagrange point that continuously monitors solar wind conditions and provides real-time space weather and Earth observation data.
-
B.
Oort cloud
The Oort cloud is a distant, spherical shell of icy bodies surrounding the Solar System, thought to be the source of many long-period comets.
-
C.
Epsilon Eridani
Epsilon Eridani is a nearby young K-type main-sequence star in the constellation Eridanus, notable for its debris disk and status as a prominent target in exoplanet and SETI searches.
-
D.
Tau Ceti
Tau Ceti is a nearby Sun-like star in the constellation Cetus, notable for its stability, potential planetary system, and historical importance as an early target in the search for extraterrestrial intelligence.
-
E.
Orion Arm
The Orion Arm is a minor spiral arm of the Milky Way galaxy that contains our Solar System and many of the stars visible in the night sky.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Sun–Earth L2 Target entity description: Sun–Earth L2 is a gravitationally stable point in space located beyond Earth's orbit where the combined gravity of the Sun and Earth allows spacecraft, such as the James Webb Space Telescope, to maintain a relatively constant position with minimal fuel use.
-
A.
Deep Space Climate Observatory
The Deep Space Climate Observatory (DSCOVR) is a NOAA and NASA satellite positioned at the Sun–Earth L1 Lagrange point that continuously monitors solar wind conditions and provides real-time space weather and Earth observation data.
-
B.
Oort cloud
The Oort cloud is a distant, spherical shell of icy bodies surrounding the Solar System, thought to be the source of many long-period comets.
-
C.
Epsilon Eridani
Epsilon Eridani is a nearby young K-type main-sequence star in the constellation Eridanus, notable for its debris disk and status as a prominent target in exoplanet and SETI searches.
-
D.
Tau Ceti
Tau Ceti is a nearby Sun-like star in the constellation Cetus, notable for its stability, potential planetary system, and historical importance as an early target in the search for extraterrestrial intelligence.
-
E.
Orion Arm
The Orion Arm is a minor spiral arm of the Milky Way galaxy that contains our Solar System and many of the stars visible in the night sky.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
Lagrange point
ⓘ
gravitational equilibrium point ⓘ |
| advantage |
continuous view of deep space away from Sun and Earth
ⓘ
reduced fuel consumption for orbit maintenance compared to free heliocentric orbit ⓘ relatively constant geometry with Earth and Sun ⓘ stable thermal environment for spacecraft ⓘ |
| benefitForTelescopes |
minimal Earth occultation of observed sky
ⓘ
reduced stray light from Earth and Moon ⓘ simplified sunshield design ⓘ |
| communication | continuous line of sight to Earth with high-gain antenna steering ⓘ |
| coOrbitsWith | Earth ⓘ |
| coordinateFrame | Sun–Earth rotating frame ⓘ |
| directionFromEarth | away from the Sun ⓘ |
| discoveredBy | Joseph-Louis Lagrange ⓘ |
| discoveryMethod | analytical solution of restricted three-body problem ⓘ |
| distanceFromEarth |
about 0.01 astronomical units
ⓘ
approximately 1.5 million kilometers ⓘ |
| field |
astrodynamics
ⓘ
celestial mechanics ⓘ |
| gravitationalInfluence |
Earth
ⓘ
Sun ⓘ |
| illuminationCondition | Sun, Earth, and Moon remain on same side of spacecraft ⓘ |
| label | L2 ⓘ |
| locatedIn |
Solar System
ⓘ
surface form:
Sun–Earth system
|
| missionDesign | spacecraft typically orbit around L2 rather than sit exactly at the point ⓘ |
| orbitalPeriod | approximately 1 year ⓘ |
| orbits | Sun ⓘ |
| positionType | collinear Lagrange point ⓘ |
| relatedConcept | Lagrange points L1, L3, L4, L5 in Sun–Earth system ⓘ |
| relativeTo |
Earth
ⓘ
Sun ⓘ |
| requires | station-keeping maneuvers ⓘ |
| stabilityAxes |
stable in rotating frame with active control
ⓘ
unstable along radial direction ⓘ |
| stabilityType | metastable ⓘ |
| typicalOrbit |
Lissajous orbit
ⓘ
halo orbit ⓘ |
| usedBy |
Euclid spacecraft
ⓘ
Gaia observatory ⓘ
surface form:
Gaia spacecraft
Herschel Space Observatory ⓘ James Webb Space Telescope ⓘ Planck spacecraft ⓘ Spektr-RG observatory ⓘ |
| usedFor |
astrometry
ⓘ
cosmic microwave background observations ⓘ cosmology missions ⓘ infrared astronomy ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Sun–Earth L2 Description of subject: Sun–Earth L2 is a gravitationally stable point in space located beyond Earth's orbit where the combined gravity of the Sun and Earth allows spacecraft, such as the James Webb Space Telescope, to maintain a relatively constant position with minimal fuel use.
Referenced by (18)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Sun–Earth L2 point
this entity surface form:
Sun–Earth L2 point
this entity surface form:
Sun–Earth L2 point
this entity surface form:
Sun–Earth L2 point
this entity surface form:
Sun–Earth L2 halo orbit
this entity surface form:
Sun–Earth L2 Lagrange point
subject surface form:
Sun–Earth L2
this entity surface form:
second Lagrange point of the Sun–Earth system
this entity surface form:
Sun–Earth L2 point
subject surface form:
Integrated Science Instrument Module
this entity surface form:
Sun–Earth L2 halo orbit
this entity surface form:
Sun–Earth L2 point
this entity surface form:
Sun–Earth L2 point (planned for Roman Space Telescope)
this entity surface form:
Sun–Earth L2 point
this entity surface form:
Sun–Earth L2 Lagrange point
this entity surface form:
Sun–Earth L2 via Herschel Space Observatory
this entity surface form:
Sun–Earth L2 Lagrange point