Voyager 1 at the speed it moved outward over the year to 2026-10-25 (JPL Horizons). Driving: nonstop, never refuelling.
How it was found
First planet found in 2011, by transit (NASA Exoplanet Archive).
Its planets
Kepler-42 b — 0.8 times Earth's width, smaller than the Earth; its year lasts 29 hours; about 250 °C, hotter than boiling water; found in 2011 by transit.
Kepler-42 c — 0.7 times Earth's width, smaller than the Earth; its year lasts 11 hours; about 450 °C, hotter than boiling water; found in 2011 by transit.
Kepler-42 d — 0.6 times Earth's width, smaller than the Earth; its year lasts 45 hours; about 180 °C, hotter than boiling water; found in 2011 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.