100 atoms per cubic meter is on the lower end of typical densities in the interstellar medium. It can get many orders of magnitude denser than that.
Outside galaxies you have better chances of surviving high speeds. The intergalactic medium is only 1-10 particles per cubic meter in the web of gas we call the warm–hot intergalactic medium, and possibly less outside of that.
Outside galaxies you have better chances of surviving high speeds. The intergalactic medium is only 1-10 particles per cubic meter in the web of gas we call the warm–hot intergalactic medium, and possibly less outside of that.