NASA’s Juno spacecraft has sent its first image back to Earth as it flew over Europa, Jupiter’s icy moon and one of the candidate worlds for harbor life in its subterranean ocean. The photograph, which shows the surface in a region near the equator called Annwn Regio, was captured during the probe’s closest approach on Thursday, September 29 at 11:36 a.m. Spanish Peninsular Time, at a distance of approximately 352 kilometers.
This is the closest spacecraft look at Europa since January 3, 2000, when NASA’s Galileo came within 351 kilometers of the moon’s surface.
Europa is the sixth largest moon in the solar system, slightly smaller than Earth’s moon. Scientists believe that a salty ocean it lies beneath a layer of ice miles thick, raising questions about possible conditions capable of supporting life below Europa’s surface.
impact crater
The flyby image, taken by the JunoCam camera, points to a strip of Europa’s surface north of the equator. Rugged terrain features are easily seen, including tall blocks that cast shadows, while bright and dark ridges and valleys curve along the surface. A degraded impact crater also appears to be visible.
Juno only had a two-hour window to collect this data, zipping past the moon at a relative speed of about 14 miles per second.
“It’s very early, but everything indicates that the flyby was a huge success,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio, USA. “This first image is just a glimpse of the remarkable new science that will emerge from Juno’s full suite of instruments and sensors that acquired data as we skimmed across the moon’s icy crust.”
During the flyby, the mission collected what will be some of the highest resolution images of the moon (1 kilometer per pixel) and obtained valuable data on the structure of the Europa ice sheet, the interior, the composition of the surface and the ionosphere, as well as the moon’s interaction with Jupiter’s magnetosphere.
“The science team will compare 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,” said Candy Hansen, a Juno co-investigator leading the planning of the camera at the Planetary Science Institute in Tucson, Arizona. “JunoCam images will complete the current geological map.”
Europa Clipper
Scientists can use all of this information to generate new insights about the moon, including data in the search for regions where liquid water may exist in shallow underground patches.
These observations will be useful for future missions to the Jovian moon, including Europa Clipper. Scheduled to launch in 2024 and reach Europa in 2030, it will study the moon’s atmosphere, surface and interior, with the main scientific goal of determining whether there are places below the surface that could support life. The mission will attempt to better understand the global subsurface ocean, the thickness of its ice crust, and look for possible plumes that may be expelling subsurface water into space.
The close flyby altered Juno’s trajectory, reducing the time it takes to orbit Jupiter from 43 days to 38 days. The flyby also marks the second encounter with a Galilean moon during Juno’s extended mission. The mission explored Ganymede in June 2021 and is scheduled to conduct close flybys of Io, the most volcanic body in the solar system, in 2023 and 2024.