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
The Planets: A Modern Allegory The Planets: A Modern Allegory The Planets: A Modern Allegory is a radio play, written in verse, by Alfred Kreymborg. The first performance was on 6 June 1938 by the National Broadcasting Company at the Hayden Planetarium in New York City, and was directed by Thomas L. Riley. The play was originally set to the music of "The Planets" Suite by Gustav Holst; for the first performance the NBC Symphony Orchestra was conducted by H. Leopold Spitalny. The first broadcast was so enthusiastically received that it was repeated a few weeks later. The play describes the early history of the