An alien world just two-thirds the size of Earth - one of the smallest on record - has been detected by NASA's Spitzer Space Telescope.
The exoplanet candidate, known as UCF-1.01, orbits a star called GJ 436, which is located a mere 33 light-years away.
UCF-1.01 might be the nearest world to our solar system that is smaller than our home planet. But the planet is unlikely to be habitable due to its molten surface and the little, if any, atmosphere.
Evidence for UCF1.01 turned up when astronomers were studying a known Neptune-sized exoplanet, called GJ436, seen in the background of the image above.
The identification of nearby small planets may lead to their characterisation using future more advanced instruments. In this way, worlds such as UCF-1.01 might serve as stepping stones to one day finding a habitable, Earth-like exoplanet.
Of Kepler's 1800 candidate stars, only three have been confirmed to have planets smaller than Earth and just one is believed to be smaller than Spitzer's potential find.