An eclipse rolling across Jupiter
Processed image. Hubble observed this alignment on 24 January 2015 at 06:28 UTC. Callisto and Io are visible over the clouds; the three shadows belong, from left to right, to Europa, Callisto and Io. Europa itself is outside this view. Colour combines WFC3 exposures at 395, 502 and 631 nanometres; this is a processed observation, not an orbit simulation.
Creative Commons Attribution 4.0 · resized to WebP
· Original image source · Image licenceA moon’s shadow becomes a dark island on moving clouds.
- World
- Jupiter
- Case date or period
- Observations · 1979–2022
Look closer
Io and Ganymede cast shadows onto Jupiter in these separate encounters. The apparent size and shape depend on the moon, the geometry and the spacecraft’s viewing position.
Follow the moving shadows
Start with Hubble’s photographic time-lapse and compare its two gallery views, taken 42 minutes apart. The small bright moons and their dark shadows travel separately across the clouds. Juno’s much closer views show different encounters with Io and Ganymede; perspective changes their apparent scale. None of these scenes is a simulation of the moons’ orbits.
Built by people looking closely
The credited image processors worked with publicly available mission observations. Their versions are part of this collection, with each person’s processing and licence retained. Compare the treatments and return to the underlying source when a small detail matters.
An eclipse seen from unusually close by
JPL’s account of Thomopoulos’ Ganymede image explains why the shadow looks so large: Juno was much closer to Jupiter than the moon casting it. An observer beneath the dark oval at the cloud tops would see a total solar eclipse. Brian Swift’s companion globe projection illustrates the camera’s limited visible area. That projection is a geometry aid, not another exposure; the apparent oval combines a real shadow with perspective on a curved planet.
Sources & further reading
- Moon Shadow — NASA Image and Video Library / JPL
- Jupiter with Io Crossing — NASA Image and Video Library / JPL
- Juno Captures Moon Shadow on Jupiter — NASA Image and Video Library / JPL
- JunoCam public image-processing gallery — Mission Juno / public contributors
- Juno Captures Moon Shadow on Jupiter — observation and Brian Swift geometry figure — NASA / JPL; Thomas Thomopoulos and Brian Swift
- Jupiter moon transit — 24 January 2015, 06:28 UTC — NASA / ESA / Hubble Heritage Team
- Jupiter moon transit — 24 January 2015, 07:10 UTC — NASA / ESA / Hubble Heritage Team
- Hubble captures a rare triple-moon conjunction — photographic time-lapse — NASA / ESA / Hubble Heritage Team / G. Bacon (STScI/AURA)
- The same observed transit, published by ESA/Hubble with reuse terms — ESA/Hubble