Ripples in Space-Time Could Reveal ‘Strange Stars’

By looking for ripples in the fabric of space-time, scientists could soon detect “strange stars” — objects made of stuff radically different from the particles that make up ordinary matter, researchers say.

The protons and neutrons that make up the nuclei of atoms are made of more basic particles known as quarks. There are six types, or “flavors,” of quarks: up, down, top, bottom, charm and strange. Each proton or neutron is made of three quarks: Each proton is composed of two up quarks and one down quark, and each neutron is made of two down quarks and one up quark.

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Do we know that quarks and other sub nucleic particles have mass?

yes.

> One place strange matter could naturally be created is inside neutron stars

Yes, this is well known. Nobody really knows what the inside of a neutron star looks like, if could be neutrons, or ordinary up/down quarks, or matter with strange quarks as the article suggests, or exotic particles such as those predicted by sypersymmetry or some theories of dark matter.

The simplest way to decide which is correct is to measure the diameter of the neutron star. Preliminary measurements give a diameter in the right ballpark, but not yet accurate enough to decide between competing theories.