Are e-cigarettes safer than regular cigarettes? This ACS Reactions video takes you inside the debate. If you want more knowledge dropped on you, check out this cover story about the race to answer e-cig safety questions: http://cenm.ag/ecigarette
Comets are the fossils of our solar system, says Carey M. Lisse, a principal scientist at the Johns Hopkins University Applied Physics Laboratory. Their interiors contain pristine material remaining from when a giant molecular cloud collapsed into both the sun and a protoplanetary disk.