Active volcanoes on Io in 3 different months

Caption NASA originale:Changes in the volcanoes on Io can be seen in these 3 views, taken by NASA's Galileo spacecraft during its 3 flybys of Io in October and November 1999 and February 2000. All the images show the active volcanoes as bright yellow, corresponding to hot lava flows that appear glowing in infrared wavelengths. The 3 views were taken by the spacecraft's near-infrared mapping spectrometer and show the comparison of a typical low-resolution observation to the high-resolution views. The Prometheus volcano is seen near the middle of all three images. Before the recent flybys, only Prometheus and three other volcanoes were known to be active in this region. After these and other high-resolution observations, scientists were able to detect 14 volcanoes in the same area. The fainter volcanoes (hot spots) show some significant changes over intervals of 1 to 3 months. The area shown by all three observations put together is about 2 million square kilometers (about 770,000 square miles)".