Aaron Sidder is a freelance writer based out of Denver, Colo. He has a master’s degree in ecology from Colorado State University. Aaron was an AGU-sponsored AAAS Mass Media Science & Engineering Fellow at National Geographic in 2016, and he has been writing for Eos ever since. In addition to Eos and National Geographic, he has written for National Geographic Kids Magazine, Smithosonian Smart News, 5280 Magazine, and the Santa Fe Institute. In his free time, he cultivates an extensive—and growing—collection of field guides from around the country.