Quark stars and strange matter

Dan Vergano's December 7, 2009 USA Today story about quark stars — for now only theoretical and believed to be composed of strange matter, a solid mass of quarks — introduced me to a whole new class of possible astronomical objects.

Remember that once upon a time black holes were only theoretical constructs — until it became increasingly clear that they were at the center of most galaxies, including our own (top).

Vergano noted "... a 'strange matter hypothesis,' suggesting that normal matter will decay into strange matter if it comes into contact with [it]."

He continued, "... in theory, like 'Ice-9' in Kurt Vonnegurt's novel "Cat's Cradle," strange matter could eat up the universe."