Planet the Sun: Jupiter is the largest, at 318 Earth masses, whereas Mercury is the smallest, at 0.055 Earth masses. The planets of the Solar System can be divided into categories based on their composition: An exoplanet (extrasolar planet) is a planet outside the Solar System. In early 1992, radio astronomers Aleksander Wolszczan and Dale Frail announced the discovery of two planets orbiting the pulsar PSR 1257+12. This discovery was confirmed, and is generally considered to be the first definitive detection of exoplanets. These pulsar planets are believed to have formed from the unusual remnants of the supernova that produced the
The Planets: A Modern Allegory The Planets: A Modern Allegory The Planets: A Modern Allegory is a radio play, written in verse, by Alfred Kreymborg. The first performance was on 6 June 1938 by the National Broadcasting Company at the Hayden Planetarium in New York City, and was directed by Thomas L. Riley. The play was originally set to the music of "The Planets" Suite by Gustav Holst; for the first performance the NBC Symphony Orchestra was conducted by H. Leopold Spitalny. The first broadcast was so enthusiastically received that it was repeated a few weeks later. The play describes the early history of the