Extragalactic planet Extragalactic planet An extragalactic planet, also known as an extragalactic exoplanet, is a star-bound planet, or rogue planet, located outside of the Milky Way galaxy. Due to the huge distances to such worlds, they would be very hard to detect directly. However, indirect evidence suggests that such planets may exist. Nonetheless, the most distant known planets are SWEEPS-11 and SWEEPS-04, located in Sagittarius, approximately 27,710 light-years from the Sun, while the Milky Way is between 100,000–180,000 light years in diameter. This means that even galactic planets located further than that distance have not been detected. A planet with a mass
To Sail Beyond the Sunset To Sail Beyond the Sunset To Sail Beyond the Sunset is a science fiction novel by American writer Robert A. Heinlein, published in 1987. It was the last novel published before his death in 1988. The title is taken from the poem "Ulysses", by Alfred Lord Tennyson. The stanza of which it is a part, quoted by a character in the novel, is as follows: <poem> ... my purpose holds To sail beyond the sunset, and the baths Of all the western stars, until I die. </poem> It is the final part of the "Lazarus Long" cycle of stories, involving