Astronomy: “Green Pea” galaxies, first classified in 2007 by amateur stargazers participating in the online project Galaxy Zoo, were the subject of a talk 10 September at the Joint European and National Astronomy Meeting by Ricardo Amorin of the Instituto de Astrofisica de Andalucia. Green Pea galaxies are compact, low-mass galaxies undergoing very high rates of star formation; they are named for their small size and greenish appearance. According to Amorin, “Discovering Green Pea galaxies has opened a new window to investigate galaxy evolution and star formation in the early universe.