Juno gets a close-up of Jupiter’s moon Europa in the highest resolution

Observations from the spacecraft’s flyby of the Moon provided the first close-up view of this ocean world in over two decades, resulting in remarkable images and unique science.

The highest-resolution photo NASA’s Juno mission has ever taken of a specific part of Jupiter’s moon Europa shows a detailed view of an enigmatic region of the moon’s severely fractured ice crust.

Covering about 93 miles (150 kilometers) by 125 miles (200 kilometers) of Europa’s surface, the image shows a region traversed by a network of fine grooves and double ridges (pairs of long parallel lines indicating elevated features in the ice). . There are dark spots near the upper right corner of the image and to the right and below center, which may be related to something erupting onto the surface from below. Below center and to the right is a surface feature reminiscent of a musical quarter note, measuring 42 miles (67 kilometers) north-south by 23 miles (37 kilometers) east-west. The white dots in the image are signatures of penetrating high-energy particles from the Moon’s highly radiative environment.

Juno’s Stellar Reference Unit (SRU) — a stellar camera used to align the spacecraft — obtained the black-and-white image during the spacecraft’s flyby of Europa on September 29, 2022, at a distance of about 256 miles (412 kilometers). With a resolution of 840 to 1,115 feet (256 to 340 meters) per pixel, the image was captured as Juno hurtled across a portion of the surface that was at night at about 15 miles per second (24 kilometers per second). Dimly lit by “Jupiter shine” – sunlight reflecting off Jupiter’s cloud tops.

Designed for low-light conditions, the SRU has also proven to be a valuable scientific tool, detecting shallow flashes in Jupiter’s atmosphere, mapping Jupiter’s enigmatic ring system and now providing a glimpse into some of Europe’s most intriguing geological formations.

“This image unlocks incredible detail in a region not previously imaged with such resolution and under such revealing lighting conditions,” said Heidi Becker, SRU’s lead co-investigator. “The science team’s use of a star tracker camera is a great example of Juno’s groundbreaking capabilities. These features are so fascinating. Understanding how they formed – and how they are connected to the history of Europe – informs us about internal and external processes that shape the ice crust.”

It’s not just Juno’s SRU scientists who will be busy analyzing data in the coming weeks. During Juno’s 45th orbit around Jupiter, all of the spacecraft’s science instruments collected data, both during the flyby of Europa and shortly 7½ hours later when Juno flew over the poles of Jupiter.

“Juno initially focused entirely on Jupiter. The team is really excited that during our extended mission we’ve expanded our investigation to three of the four Galilean satellites and Jupiter’s rings,” said Scott Bolton, Juno’s principal investigator of the Southwest Research Institute in San Antonio. “With this flyby of Europa, Juno has now seen close-up images of two of Jupiter’s most interesting moons, and their ice shell crusts look very different. In 2023, Io, the most volcanic body in the solar system, will join the association.” Juno sailed past Jupiter’s moon Ganymede – the solar system’s largest moon – in June 2021.

Europa is the sixth largest moon in the solar system at about 90% of the equatorial diameter of Earth’s moon. Scientists are certain that a salty ocean lies beneath a kilometer-thick shell of ice, raising questions about the ocean’s potential habitability. In the early 2030s, NASA’s Europa Clipper spacecraft will arrive and attempt to answer these questions about Europa’s habitability. Data from the Juno flyby provide a preview of what this mission will reveal.