Science Did Earth's water come from asteroids?

Data from a European probe orbiting a comet suggests that Earth's water came from asteroids, and not comets as was previously thought. 

By , SPACE.com

ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

Asteroids, not comets, may have delivered most of Earth's water to the planet when the solar system was young, new data from a probe orbiting a comet suggests.