Stunning Images From Juno’s Close Flyby of Jupiter Unveil Hidden Surprise

NASA’s Juno mission captured detailed images of Jupiter during its 59th close flyby, revealing the planet’s colorful belts, swirling storms, and the tiny moon Amalthea. Amalthea, with its potato-like shape and reddish hue, orbits inside Io’s orbit and emits more heat than it receives from the Sun, possibly due to electric currents induced by Jupiter’s magnetic field or tidal stresses.

On March 7, 2024, during its 59th close flyby of Jupiter, NASA’s Juno mission captured these views of the giant planet. The images provide a detailed look at Jupiter’s colorful belts and swirling storms, including the famous Great Red Spot. A thorough examination reveals a hidden surprise: two glimpses of the tiny moon Amalthea (see image below).

With a radius of just 52 miles (84 kilometers), Amalthea has a potato-like shape, lacking the mass to pull itself into a sphere. In 2000, NASA’s Galileo spacecraft revealed some surface features, including impact craters, hills, and valleys. Amalthea circles Jupiter inside Io’s orbit, which is the innermost of the planet’s four largest moons, taking 0.498 Earth days to complete one orbit.

Amalthea is the reddest object in the solar system, and observations indicate it gives out more heat than it receives from the Sun. This may be because, as it orbits within Jupiter’s powerful magnetic field, electric currents are induced in the moon’s core. Alternatively, the heat could be from tidal stresses caused by Jupiter’s gravity.

At the time that the first of these two images was taken, the Juno spacecraft was about 165,000 miles (265,000 kilometers) above Jupiter’s cloud tops, at a latitude of about 5 degrees north of the equator.

Citizen scientist Gerald Eichstädt made these images using raw data from the JunoCam instrument, applying processing techniques to enhance the clarity of the images.

JunoCam’s raw images are available for the public to peruse and process into image products at https://missionjuno.swri.edu/junocam/processing. More information about NASA citizen science can be found at https://science.nasa.gov/citizenscience and https://www.nasa.gov/solve/opportunities/citizenscience.