"<a href=""https://www.youtube.com/watch?v=-jA2ABHBc6Y&amp;t=36m30s"">36:30</a> There must be a reason why there are so many of these between Earth and Neptune sized planets in our galaxy. Depending on the number of stars in the milky way and the proportion of actual planets of this size. <br><br>So planets are remnants of a sun right? Gas and matter accrete to create stars. Stars die off and chunks of rock then went go circle around other sun. Or were the planets formed early during the formation of the universe? Lazy question. <br><br>This may or may not be related to this topic of size (Neptune and Earth / in between size)",(reply>), Detention