Planet
The smallest known planet is PSR B1257+12A, one of the first extrasolar planets discovered, which was found in 1992 in orbit around a pulsar. Its mass is roughly half that of the planet Mercury. The smallest known planet orbiting a main-sequence star other than the Sun is Kepler-37b, with a mass (and radius) slightly higher than that of the Moon.
Outline of Nauru
Nauru – sovereign island nation located in the Micronesian South Pacific. Its nearest neighbour is Banaba Island in the Republic of Kiribati, due east. Nauru is the world's smallest island nation, covering just , the smallest independent republic, and the only republican state in the world without an official capital. It is the least populous member of the United Nations.