"The solar wind is now know to be a mixture of materials found in the solar plasma, composed of ionized hydrogen (electrons and protons) with an 8% component of helium and trace amounts of heavy ions."
"At the orbit of the earth the average solar wind consists of a strongly ionized gas having a proton and electron density of about 3 - 10 particles per cubic centimeter, with an average flow velocity of approximately 400 km/s."
https://umbra.nascom.nasa.gov/spartan/the_solar_wind.html
"The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between 0.5 and 10 keV. The composition of the solar wind plasma also includes a mixture of materials found in the solar plasma: trace amounts of heavy ions and atomic nuclei such as C, N, O, Ne, Mg, Si, S, and Fe. There are also rarer traces of some other nuclei and isotopes such as P, Ti, Cr, 54Fe and 56Fe, and 58Ni, 60Ni, and 62Ni."
https://en.m.wikipedia.org/wiki/Solar_wind
"interstellar medium particles, suggested a matching interstellar hydrogen density, about 120 hydrogen atoms in a quart-sized space."
https://www.nasa.gov/feature/goddard/2020/new-evidence-our-neighborhood-in-space-is-stuffed-with-hydrogen
"So it turns out that almost everything in our universe above an atmosphere altitude of about 100 kilometers, is a plasma. Some people estimate that 99.9% of everything in the universe is a plasma.
HOST PADI BOYD: As we continue out on our plasma journey, the most significant source of plasma in our solar system … is the sun.
Don Gurnett
The sun is very hot, and it's a plasma.
HOST PADI BOYD: Stars, like our sun, are made of very hot gasses. The sun is so hot that most of its gas has been ionized into a plasma.
HOST PADI BOYD: When those plasma particles leave the sun and head out in all directions into space, we call that solar wind and we now know that every planet in our solar system encounters some of that plasma"
https://www.nasa.gov/mediacast/plasma-plasma-everywhere
"viscosity value is extremely low, close to zero."
https://www.dailymail.co.uk/sciencetech/article-2612949/Are-living-underwater-Researchers-believe-universe-liquid-superfluid.html