Ross 128 b
Planet· orbits the Sun
Ross 128 b — a temperate planet (minimum mass ~1.4 Earth) on a 9.9-day orbit around a calm red dwarf, with an equilibrium temperature near room temperature (~300 K). Whether it holds an atmosphere or water is unknown — it has never been imaged.
Open in 3D viewSee Ross 128 b in the live, interactive 3D map
Key facts
Minimum mass
8.36 × 10²⁴ kg
1.4 M⊕
Year
9.87 Earth days
Distance from Ross 128
7,420,054 km
Science
Physical
- Minimum mass (m·sin i)
- 8.36 × 10²⁴ kg · 1.4 M⊕
- Radius
- Not measured
Orbital
- Semi-major axis
- 7,420,054 km
- Eccentricity
- 0.116
- Inclination
- 0.00 °
- Orbital period
- 9.9 days
- Perihelion
- 6,559,328 km
- Aphelion
- 8,280,781 km
- Mean orbital velocity
- 54.7 km/s
Composition
- Bulk composition
- Presumed rocky (minimum mass ~1.4 Earth); whether it holds water or an atmosphere is unknown, and it has never been imaged.
- Surface appearance
- Appearance based on ESO/M. Kornmesser'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 Vision mode; Realism shows a plain spectral colour.
Radiation & temperature
- Insolation
- 1.47 S⊕ · 1.47× the sunlight Earth receives
- Equilibrium temperature
- 301 K (28 °C)
Discovery & history
- Method
- Radial-velocity detection (stellar wobble)
- Name
- Designated 'b' as the first planet found around its star, following the IAU convention of lettering planets in discovery order from 'b'.
Announced in 2017 by ESO's HARPS team as one of the nearest temperate exoplanets. Because its host star flares far less than Proxima Centauri, Ross 128 b is often cited as a comparatively gentle environment — though its true conditions remain unknown.
Images
No official imagery available — this object has never been visited and no officially-licensed depiction exists.