‘Potato Moon’ Photobombs Jupiter’s Great Red Spot In New NASA Images
NASA’s Juno mission captured these views of Jupiter during its 59th close flyby of the giant planet … [+]
Image data: NASA/JPL-Caltech/SwRI/MSSS. Image processing by Gerald Eichstädt
Jupiter has at least 92 moons, but rarely are any but the very largest ever imaged by passing spacecraft.
New images returned by NASA spacecraft Juno across 560 million miles (900 million kilometers) Amalthea, a tiny moon with a radius of just 52 miles (84 kilometers).
The images show Amalthea above Jupiter’s “Great Red Spot,” an anticyclonic storm roughly the diameter of Earth that’s been raging since at least 1831.
Planetary scientists have not seen the potato-shaped moon since 2000, when NASA’s Galileo spacecraft revealed impact craters, hills and valleys on Amalthea.
Seeing Red
Amalthea is the reddest object in the solar system, according to NASA. It orbits very close to the giant planet—closer even than Io, the most volcanic world in the solar system. Amalthea takes less than half a day to orbit Jupiter.
Scientists think Amalthea gives out more heat than it receives from the sun, possibly because electric currents are induced in the moon’s core. However, it could be—as is the case with Io—that tidal stresses caused by Jupiter’s gravity creates a lot of heat.
NASA’s Juno mission captured these views of Jupiter during its 59th close flyby of the giant planet … [+]
Image data: NASA/JPL-Caltech/SwRI/MSSS. Image processing by Gerald Eichstädt
Juno’s Journey
NASA’s Juno has been orbiting Jupiter since 2016, capturing multiple images of the planet’s giant moons—Io, Europa, Callisto and Ganymede.
The image of Amalthea was taken by Juno on March 7, 2024 during its 59th close flyby (perijove) while it was 165,000 miles (265,000 kilometers) above Jupiter’s cloud tops.
The tiny moon was revealed after citizen scientist Gerald Eichstädt post-processed the raw images sent back by Juno.
‘Great Red Spot’
A 400-years old storm that used to be twice the size of Earth, the “Great Red Spot” is an anticyclonic storm rolling counterclockwise between two bands of clouds that are moving in opposite directions toward it. It has 425 miles per hour winds.
An image taken in 2019 by the Hubble Space Telescope confirmed that it’s continuing to shrink. Astronomers don’t know why, but they do know that smaller storms on Jupiter are typically white or brown ovals lasting from a few hours to a few centuries.
Just below the “Great Red Spot” is a worm-shaped vortex spinning in the opposite direction, as well as two large anticyclones seen as white ovals.
Two new views of Jupiter
NASA, ESA, A. Simon (Goddard Space Flight Center), and M. H. Wong (University of California, Berkeley) and the OPAL team.
Jupiter’s Many Moons
Scientists found 12 new moons orbiting Jupiter in 2023, taking the total to 92, though all of the newly-found moons are just 0.6 miles to 2 miles in size. They’re also all outer moons orbiting over 550 miles from the giant planet. All take over 340 and up to 550 Earth-days to orbit Jupiter, according to Sky & Telescope magazine.
Nine of the new moons orbit in the opposite direction to the the inner moons, which suggests that they are objects captured by Jupiter’s gravity.
Wishing you wide eyes and clear skies
