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,
Third from the Sun called "Earth". Todd VanDerWerff of "The A.V. Club" rated it A and called the twist "justifiably famous". The episode contains an anomaly: the planet revealed as being Earth is described as being in another solar system, "11 million miles" away. The next closest solar system to our sun is actually 25.7 trillion miles away. Third from the Sun "Third from the Sun" is episode 14 of the American television anthology series "The Twilight Zone". It is based on a short story of the same name by Richard Matheson which first appeared in the first issue of the magazine "Galaxy Science