NASA’s Terra satellite captured this image of “the troublesome trio” on Papua New Guinea’s New Britain island when they erupted simultaneously on 9 August 2005. Langila, Ulawun, and Rabaul Volcanoes all spewed ash at the same time, though not all with the same results. The westernmost volcano, Langila, and the easternmost volcano, Rabaul, sent fairly faint plumes of ash into the air, both of which drifted toward the northwest. Ulawun, the most active volcano in this picture, spit out a dense stream of ash that flew straight south. The volcanoes’ proximity to each other and propensity for acting up at the same time suggest that they could be affected by the same tectonic activity underground. Photo courtesy of NASA.