TOI-700 d
Planet· orbits TOI-700
TOI-700 d — an Earth-size planet (1.07 Earth radii) in the star's HABITABLE ZONE, orbiting every 37 days: TESS's first such world. Its size is measured; its mass is size-estimated, so no density is quoted. It may be rocky and temperate — a key target in the search for life's ingredients. Never imaged.
Open in 3D viewSee TOI-700 d in the live, interactive 3D map
Key facts
Radius
6,836 km
1.07× wider than Earth
Year
37.42 Earth days
Distance from TOI-700
0.163 AU
Science
Physical
- Radius
- 6,836 km · 1.07× wider than Earth
Orbital
- Semi-major axis
- 0.163 AU
- From the NASA Exoplanet Archive (transit + orbit fit); a 2026 preprint (Pass et al., arXiv:2604.05235 — JWST+TESS+Spitzer) reports more precise ephemerides, pending peer review
- Eccentricity
- 0
- From the NASA Exoplanet Archive (transit + orbit fit); a 2026 preprint (Pass et al., arXiv:2604.05235 — JWST+TESS+Spitzer) reports more precise ephemerides, pending peer review
- Inclination
- 0.00 °
- From the NASA Exoplanet Archive (transit + orbit fit); a 2026 preprint (Pass et al., arXiv:2604.05235 — JWST+TESS+Spitzer) reports more precise ephemerides, pending peer review
- Orbital period
- 37.4 days
- From the NASA Exoplanet Archive (transit + orbit fit); a 2026 preprint (Pass et al., arXiv:2604.05235 — JWST+TESS+Spitzer) reports more precise ephemerides, pending peer review
- Perihelion
- 0.163 AU
- Computed from the orbital elements
- Aphelion
- 0.163 AU
- Computed from the orbital elements
- Mean orbital velocity
- 47.5 km/s
- Computed from the orbital elements
Composition
- Bulk composition
- An Earth-size planet (1.07 Earth radii) in the star's habitable zone — TESS's first such world; its size is measured, its mass only size-estimated, so no density is quoted. Possibly rocky and temperate. Never imaged.
- Surface appearance
- Appearance based on NASA/JPL-Caltech's artist's concept. No spacecraft has imaged this world, so its real appearance is unknown — The surface shown is an artistic representation, shown only in Visual mode; Realism shows a plain spectral colour.
Radiation & temperature
- Insolation
- 0.857 S⊕ · 86% of the sunlight Earth receives
- Computed from TOI-700's luminosity and the orbital distance (inverse-square; Earth's sunlight = 1).
- Equilibrium temperature
- 269 K (-4 °C)
- Computed model value for its 37-day habitable-zone orbit — not measured.
Discovery & history
- Discovered
- January 6, 2020
- Method
- Transit detection
- Name
- Designated 'd' under the IAU convention that letters a star's planets 'b', 'c', 'd'... in the order they are found (the star is the unwritten 'a'); no IAU proper name has been assigned.
Confirmed in 2020 as the first Earth-size habitable-zone planet found by TESS — a headline result for the mission.
Images
Images from open archives · credit shown per image