Voyager 1 alla velocità con cui si è allontanata nell'anno fino al 2026-10-25 (JPL Horizons). In auto: senza sosta, senza mai fare rifornimento.
Come è stato scoperto
Primo pianeta scoperto nel 2015 con il transito (NASA Exoplanet Archive).
I suoi pianeti
K2-21 b — 1.8 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 9 days; about 230 °C, hotter than boiling water; found in 2015 by transit.
K2-21 c — 2.5 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 16 days; about 150 °C, hotter than boiling water; found in 2015 by transit.
NASA Exoplanet Archive, Planetary Systems Composite Parameters (fetched 2026-11-02). Composite values: where a planet's size or mass was not measured, the archive estimates it from the other.
This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with NASA under the Exoplanet Exploration Program.