Loki Patera is the largest volcanic depression on Jupiter’s moon Io, 202 km in diameter. It contains an active lava lake, with an episodically overturning crust. Voyager 1 took this composite picture of Io showing an active plume from Loki on the moon’s limb. The images that make up this mosaic were taken from an average distance of approximately 490,000 km.
A plume rises from a volcano over 300 km above Jupiter’s moon Io in this image from the New Horizons spacecraft. The volcano Tvashtar is marked by the bright glow (about 1 o’clock) at the moon’s edge, beyond the day/night shadow line. The shadow of Io cuts across the plume itself. The image was recorded when the spacecraft was 2.3 million kilometers from Io. The New Horizons spacecraft is to encounter Pluto in 2015.
Image Credit: NASA