👉 A subsphere is a region in an astrophysical or celestial system where the density of matter is significantly less than that of the surrounding gas and dust. It is characterized by a thin, dense layer of gas and dust surrounded by a thin, denser layer of material beyond it. The density of the material above the subsphere can be much lower than the density of the surrounding material, which creates a phenomenon known as subsonic expansion. This means that the temperature and pressure decrease rapidly below
