Solar System 7 light-years away. Compared to many other planetary systems, the Solar System stands out in lacking planets interior to the orbit of Mercury. The known Solar System also lacks super-Earths (Planet Nine could be a super-Earth beyond the known Solar System). Uncommonly, it has only small rocky planets and large gas giants; elsewhere planets of intermediate size are typical—both rocky and gas—so there is no "gap" as seen between the size of Earth and of Neptune (with a radius 3.8 times as large). Also, these super-Earths have closer orbits than Mercury. This led to hypothesis that all planetary systems start
Solar hot water in Australia greenhouse gas and carbon emissions. In the case of Victoria, for example, converting from electric to solar hot water could save 20% of the state's total greenhouse gas emissions. Despite an excellent solar resource, the penetration of solar water heaters in the Australian domestic market is only about 4% or 5%, with new dwellings accounting for most sales. During the 1950s, Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) carried out world leading research into flat plate solar water heaters. A solar water heater manufacturing industry was subsequently established in Australia and a large proportion of the manufactured product was