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
Aonia Terra Aonia Terra Aonia Terra is a region in the southern hemisphere of the planet Mars. It is named after a classical albedo feature, the "Bay of the Muses" and its name was approved in 1979, by the International Astronomical Union (IAU) Working Group for Planetary System Nomenclature. It is centered at and covers 3900 km at its broadest extent. It covers latitudes 30 to 81 South and longitudes 60 to 163 W. Aonia Terra is an upland area notable for massive cratering including the large Lowell Crater, parts of the region features small craters, in the plain areas, Thaumasia Fossae