How vacuous is intergalactic space?
The emptiness of space is explained in many articles... But, space does contain some matter due to these possible reasons:
During the explosion of supernovae, some elements are created. Not all supernovae nucleosynthesis are successful. So, there should be some scattering of matter into outer space.
Cosmic rays are coming from interstellar space (and even from sun) in all directions. Would all of the particles have enough efficiency to reach their destination (I mean, take earth or any other interstellar object)?. Some protons or neutrons could be scattered into space.
Even the gaseous molecules in atmosphere of celestial bodies have possibility to reach escape velocity and go into space.
Are my assumptions correct? If so, then space must contain elements up to some extent. Isn't it? Or is it due to the infiniteness of space, that these scattered particles are ignored?