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 which "Swansea Town", with its "sophisticated tone", is deemed by Dickinson to be the most memorable. Holst downplayed such music as "a limited form of art" in which "mannerisms are almost inevitable"; the composer Alan Gibbs, however, believes Holst's set at least equal to Vaughan Williams's "Five English Folk Songs" of 1913. Holst's first major work after "The Planets" was the "Hymn of Jesus", completed in 1917. The words are from a Gnostic text, the apocryphal Acts of St John, using a translation from the Greek which Holst prepared with assistance from Clifford Bax and Jane Joseph. Head comments on