"In a new article published in Nature Communications, a team centered at the University of Helsinki provided a first-ever quantitative estimate for the likelihood of quark-matter cores inside massive neutron stars. They showed that, based on current astrophysical observations, quark matter is almost inevitable in the most massive neutron stars: a quantitative estimate that the team extracted placed the likelihood in the range of 80–90%."

edit: removed my personal crackpot musings surrounding the subject. I do however, still suggest for those interested on the subject to study/brush up on quantum chromodynamics (focusing on the quark sea) and zero-point energy - never neglecting Relativity, of course. They're all very much connected and I believe the ZPE field will be a focus of continuous, real experimental science, with significant ramifications in cosmology.

edit 2: Found this research just today on nucleon liquid Vs quark liquid - very interesting and very much related to this original post.