Stars are the result of the gravitational collapse of huge clouds of gas and dust, whereas planets are thought to evolve by the accretion of the material left over from such collapses, which forms a rotating disc around the newly created star.

ECONOMIST: Twinkle, twinkle, giant planet

Rotating quarterbacks and a November injury to star running back Frank Gore derailed that possibility in a big way, and the Niners front office seems to be all right with that.

FORBES: NFL Free Agency: 3 Teams That Will Regret the Moves They've Made

It was that pulsars are rotating neutron stars, the super-dense last stage of collapse of a star not quite heavy enough to form a black hole.

ECONOMIST: Obituary