How was Galileo affected by the high radiation levels at Io?
For scientists, these thrilling encounters yielded a bonanza of pictures and information, but for Galileo engineers, the flybys presented a serious challenge with uncertain results. Io’s orbit lies in a region of intense radiation in Jupiter’s radiation belts, which took its toll on the spacecraft. Because of the radiation risk, the Io encounters were scheduled for the end of the two-year extended mission, after the spacecraft had already fulfilled its other mission objectives. A mere fraction of the dose that Galileo received would be fatal to a human. Most of the Io images were taken using a “fast camera” mode, where the camera itself pre-processes the image to average the brightness in adjacent parts of the picture. Galileo engineers say it appears that Jupiter’s radiation caused the process to get out of sync, which degraded the quality of the images. Fortunately, images that were taken in other camera modes apparently did not suffer ill effects from the radiation. When we’re flyin
