Dark matter candidates

News on the Dark Matter front: the "axion", which to me sounds vaguely Aquinan, is taking on the load of more unanswered questions in physics.

Call me a more dubious Catholic than was that particular Saint Thomas, but I'd rather see proposals for answers than increase the scope of the question. The D Star Hexaquark is a thought.

UPDATE 3/26 - The sterile neutrino just shot a blank.

UPDATE 1/15/2021 - Magnificent Seven neutron-stars. They're magnificent because they have high-energy X-rays despite being "boring", as these go; they're not even pulsar - let alone magnetar (we only know 31 of these). Anyway, the axion is just, like, their opinion man. But testable!