ananyo writes: "Vesta, the second-most-massive body in the asteroid belt, was thought to be bone dry. But NASA’s Dawn spacecraft has found evidence that smaller, water-rich asteroids once implanted themselves in Vesta’s surface. The water stays locked up in hydrated minerals until subsequent impacts create enough heat to melt the rock and release the water as a gas, leaving pitted vents in the surface. The discovery shows that yet another body in the inner Solar System has a water cycle."
"The fundamental principle of science, the definition almost, is this: the
sole test of the validity of any idea is experiment."
-- Richard P. Feynman