For 10 points, name these small particles that comprise most ring systems.
Most models of this substance outside of the Milky Way Galaxy are based on studies of the Okroy Cloud. This kind of substance is modeled by the second component of the stress-energy tensor in the Gödel solution to Einstein's Field Equations. This material can be found in Bok Globules and is responsible for stellar extinction. Radiation pressure forces it to spiral into the sun via the (*) Poynting-Robertson effect. NASA uses a set-up with aerogels to capture this substance, which is forced into a circular orbit around planetary bodies via a shepherding mechanism. Ionized gas and this substance comprise the interstellar medium. For 10 points, name these small particles that comprise most ring systems.
Most models of this substance outside of the Milky Way Galaxy are based on studies of the Okroy Cloud.
space dust [or intergalactic dust or interstellar dust or Godel dust or whatever]