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 and radial velocity (NASA Exoplanet Archive).
Its planets
Kepler-25 b — 2.8 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 6 days; about 910 °C, hotter than boiling water; found in 2011 by transit.
Kepler-25 c — 5.2 times Earth's width, Neptune-sized; its year lasts 13 days; about 660 °C, hotter than boiling water; found in 2011 by transit.
Kepler-25 d — 10 times Earth's width (estimated from its mass, not measured), a giant, Jupiter-sized or more; its year lasts 120 days; about 270 °C, hotter than boiling water; found in 2014 by radial velocity.
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.