Carolyn Wilke is a freelance science journalist and former staff writer at Science News for Students. She holds a Ph.D. in environmental engineering at Northwestern University, where she studied how light plays into the chemistry and toxicity of different types of nanoparticles under environmental conditions. Her experience as a AAAS Mass Media Fellow at The Sacramento Bee convinced her to leave the lab to write about science instead. Carolyn is a former Science News intern and has also reported on the life sciences for The Scientist. She enjoys writing about materials science, chemistry, microbiology and all things related to the environment.