Juno’s close pass of Europa on September 29 (1036 UTC) took it within 352 kilometers of the icy moon, marking the third close pass in history below 500 kilometers. The encounter saw the spacecraft come within a single kilometer of Galileo’s 351 kilometers from the surface back in January of 2000, and it provided the opportunity for Juno to use its JunoCam to home in on a region north of Europa’s equator. Note the high relief of terrain along the terminator, with its ridges and troughs starkly evident.
Image: The complex, ice-covered surface of Jupiter’s moon Europa was captured by NASA’s Juno spacecraft during a flyby on Sept. 29, 2022. At closest approach, the spacecraft came within a distance of about 352 kilometers. Credit: NASA/JPL-Caltech/SWRI/MSSS.
This first image from JunoCam captures features at the region called Annwn Regio, and was collected in the two-hour window available to Juno as it moved past Europa at 23.6 kilometers per second. What we hope to gain from analysis of the data should be high resolution images at approximately 1 kilometer per pixel, along with data on the ice shell covering the moon’s ocean, along with a good deal more about its surface composition, its internal structure and tenuous ionosphere. Says Candy Hansen, a Juno co-investigator (Planetary Science Institute, Tucson):
“The science team will be comparing the full set of images obtained by Juno with images from previous missions, looking to see if Europa’s surface features have changed over the past two decades. The JunoCam images will fill in the current geologic map, replacing existing low-resolution coverage of the area.”
In other words, more JunoCam imagery to come, all useful to the upcoming Europa Clipper and JUICE missions. In particular, data from the spacecraft’s Microwave Radiometer should fill in our understanding of variations in Europa’s ice beneath the crust, and possibly point to regions where liquid water may be captured in subsurface pockets.