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
Gustav Holst mer". Holst began composing "The Planets" in 1914; the movements appeared not quite in their final sequence; "Mars" was the first to be written, followed by "Venus" and "Jupiter". "Saturn", "Uranus" and "Neptune" were all composed during 1915, and "Mercury" was completed in 1916. Each planet is represented with a distinct character; Dickinson observes that "no planet borrows colour from another". In "Mars", a persistent, uneven rhythmic cell consisting of five beats, combined with trumpet calls and harmonic dissonance provides battle music which Short asserts is unique in its expression of violence and sheer terror, "... Holst's intention being to