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,
Gliese 777 b given minimum mass. The planet has one of the longest orbits currently known for an extrasolar planet. The planet's mean distance from the star is close to the distance between Jupiter and the Sun. However, unlike Jupiter it has an eccentric orbit. At periastron the distance between the planet and the star is only 2.51 AU and at apastron the distance is as much as 5.33 AU (compared to the Solar System, distance from the Sun to the inner asteroid belt and from Sun to just beyond the orbit of Jupiter). The signal produced by the planet is very weak