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 power in the United States the United States ranked 2nd in the world behind China. In 2016, 39% of all new electricity generation capacity in the country came from solar, more than any other source and ahead of natural gas (29%). By 2015, solar employment had overtaken oil and gas as well as coal employment in the United States. In 2016, more than 260,000 Americans were employed in the solar industry. The United States conducted much early research in photovoltaics and concentrated solar power. It is among the top countries in the world in electricity generated by the Sun and several of the world's largest