Spinning Comets Can Tear Themselves Apart, Only to Be Reborn

Comets may often experience repeated cycles of destruction and reformation, spinning fast enough to break up but then reforming as their separate pieces slowly coalesce over time, a new study finds. This finding could help explain the odd shapes of many comets imaged so far, researchers say. Comets are clumps of ice and rock that generate long tails as their orbits bring them near the sun.