Enhanced natural colour image, taken by Voyager 1, of the eruption of Io's huge volcano, Pele. The vent of Pele is to the upper right, at the top of the triangular wedge of mountains. The volcano is throwing a plume of gases 300 km upwards. They are invisible against the bright surface of Io, but appear as a wide, bright plume against the dark sky off the edge of Io. These gases rain down to produce the heart-shaped marks around Pele that are 1400 km across. At bottom right is the very dark, inactive volcano, Babbar Patera. To the left is the complex Galai Patera region. Galai Patera itself is the heel-shaped caldera at lower left.