Geology of solar terrestrial planets Geology of solar terrestrial planets The geology of solar terrestrial planets mainly deals with the geological aspects of the four terrestrial planets of the Solar System – Mercury, Venus, Earth, and Mars – and one terrestrial dwarf planet: Ceres. Earth is the only terrestrial planet known to have an active hydrosphere. Terrestrial planets are substantially different from the giant planets, which might not have solid surfaces and are composed mostly of some combination of hydrogen, helium, and water existing in various physical states. Terrestrial planets have a compact, rocky surfaces, and Venus, Earth, and Mars each also have an atmosphere.
Gustav Holst found his genuine voice in his setting of Whitman's verses, "The Mystic Trumpeter" (1904), in which the trumpet calls that characterise Mars in "The Planets" are briefly anticipated. In this work, Holst first employs the technique of bitonality—the use of two keys simultaneously. At the beginning of the 20th century, according to Matthews, it appeared that Holst might follow Schoenberg into late Romanticism. Instead, as Holst recognised afterwards, his encounter with Purcell's "Dido and Aeneas" prompted his searching for a "musical idiom of the English language"; the folksong revival became a further catalyst for Holst to seek inspiration from other