Solar System largely of materials with lower melting points. The boundary in the Solar System beyond which those volatile substances could condense is known as the frost line, and it lies at roughly 5 AU from the Sun. The objects of the inner Solar System are composed mostly of rock, the collective name for compounds with high melting points, such as silicates, iron or nickel, that remained solid under almost all conditions in the protoplanetary nebula. Jupiter and Saturn are composed mainly of gases, the astronomical term for materials with extremely low melting points and high vapour pressure, such as hydrogen, helium,
The empire on which the sun never sets Empire". From the mid-nineteenth century, the image of the sun never setting can be found applied to Anglophone culture, explicitly including both the British Empire and the United States, for example in a speech by Alexander Campbell in 1852: "To Britain and America God has granted the possession of the new world; and because the sun never sets upon our religion, our language and our arts...". By the end of the century, the phrase was also being applied to the United States alone. An 1897 magazine article titled "The Greatest Nation on Earth" boasted, "[T]he sun never sets on Uncle