Detail of one of the calderas, or collapsed volcanic craters, on
Jupiter's moon Io, is seen in these images acquired on February
22, 2000by NASA's Galileo spacecraft. Taken from a distance of
700 to 800 kilometers (roughly 400 to 500 miles). The five
partial images on the right comprise all of the data that could
be returned from an eight-image mosaic. These are the highest
resolution images of lava flows ever obtained from Io. The
resolution of the close-up images varies from 7 to 8 meters
(about 23 to 26 feet) per picture element. The boxes in the
image to the left are approximate locations of the five partial
images. They are shown superimposed on a lower resolution image
of the entire Chaac caldera. The high-resolution snapshots
highlight areas from both the southern and northern rims as well
as areas on the floor of the caldera. They reveal fascinating
similarities and differences between calderas on Io and Earth.
Most puzzling is the texture of the material above the caldera
rim. The plains surrounding