NASA’s Juno spacecraft has captured rare images of Jupiter’s tiny moon, Amalthea, above the planet’s famous “Great Red Spot.” The potato-shaped moon, measuring just 52 miles in radius, is rarely imaged by passing spacecraft due to its small size. The images reveal impact craters, hills, and valleys on Amalthea, which is known as the reddest object in the solar system. Scientists believe that the moon gives out more heat than it receives from the sun, possibly due to electric currents induced in its core or tidal stresses caused by Jupiter’s gravity.
Juno, which has been orbiting Jupiter since 2016, captured the image of Amalthea during its 59th close flyby in March 2024. The spacecraft was 165,000 miles above Jupiter’s cloud tops when the image was taken. The discovery of Amalthea comes after scientists found 12 new moons orbiting Jupiter in 2023, bringing the total number of moons to 92. These newly-found moons are small, ranging in size from 0.6 miles to 2 miles, and all orbit at a distance of over 550 miles from the giant planet. The moons take between 340 and 550 Earth-days to orbit Jupiter.
The “Great Red Spot” on Jupiter, a 400-year-old anticyclonic storm the size of Earth, was also captured in the images taken by Juno. The storm, which has been raging since at least 1831, has 425 miles per hour winds and continues to shrink. Below the “Great Red Spot,” a worm-shaped vortex and two large anticyclones are visible, showing the dynamic and complex atmosphere of the gas giant. Smaller storms on Jupiter are typically white or brown ovals that can last from a few hours to a few centuries.
The discovery of Amalthea and the stunning images of Jupiter’s “Great Red Spot” provide valuable insight into the moons and storms of the gas giant. Planetary scientists are analyzing the images to understand the geological features of Amalthea and the dynamics of the “Great Red Spot.” With Juno continuing to orbit Jupiter and capture new data, there is hope for more discoveries and insights into the mysteries of the largest planet in our solar system.
As Juno continues its mission, scientists and astronomers are eagerly anticipating more discoveries and insights into Jupiter and its vast moon system. The images captured by the spacecraft provide a glimpse into the unique features and phenomena of the gas giant, allowing researchers to expand their knowledge of this fascinating planet. The discoveries of new moons and the ongoing study of Jupiter’s storms are contributing to a better understanding of the complex and dynamic processes that occur in our solar system’s largest planet.
