Planet consists mostly of planets the size of Neptune and smaller, down to smaller than Mercury. There are types of planets that do not exist in the Solar System: super-Earths and mini-Neptunes, which could be rocky like Earth or a mixture of volatiles and gas like Neptune—a radius of 1.75 times that of Earth is a possible dividing line between the two types of planet. There are hot Jupiters that orbit very close to their star and may evaporate to become chthonian planets, which are the leftover cores. Another possible type of planet is carbon planets, which form in systems with
Wonders of the Solar System Wonders of the Solar System Wonders of the Solar System is a 2010 television series co-produced by the BBC and Science Channel, and hosted by physicist Brian Cox. "Wonders of the Solar System" was first broadcast in the United Kingdom on BBC Two on 7 March 2010. The series comprises five episodes, each of which focuses on an aspect of the Solar System and features a 'wonder' relevant to the theme. The series was described as one of the most successful to appear on BBC Two in recent years. An accompanying book with the same name was also published. On