Triple Eclipse

  • Released Thursday, August 29, 2013

Each time one of Jupiter’s large inner moons passes between the sun and the gas giant, a dark shadow is cast on the planet. That’s exactly what happened on March 28, 2004, when the Hubble Space Telescope imaged three of Jupiter’s moons eclipsing the sun. A series of images taken at different near-infrared wavelengths show the shadows of Io, Ganymede and Callisto traveling across Jupiter’s mighty disk. These moons make up three of the four Jovian moons discovered by Galileo in the early 1600s. The fourth moon, Europa, was located on the opposite side of the planet at the time of the observation. Watch the animation to see the event unfold.

Shadows in order of appearance: Callisto, Io, Ganymede. The moons Io (white) and Ganymede (blue) can also be seen.

Compared to Ganymede and Callisto, Io (above) is smallest in size. Its strange yellow color is due to volcanic activity.

Compared to Ganymede and Callisto, Io (above) is smallest in size. Its strange yellow color is due to volcanic activity.

Ganymede (above) is Jupiter's largest moon. At three-quarters the size of Mars, it's also the biggest moon in the solar system.

Ganymede (above) is Jupiter's largest moon. At three-quarters the size of Mars, it's also the biggest moon in the solar system.

Callisto (above) orbits Jupiter at a greater distance than Io and Ganymede. The visible craters on its surface point to a violent past.

Callisto (above) orbits Jupiter at a greater distance than Io and Ganymede. The visible craters on its surface point to a violent past.



Credits

Please give credit for this item to:
NASA's Goddard Space Flight Center
Video and eclipse images courtesy of NASA/ESA/University of Arizona/E. Karkoschka
Io image courtesy of NASA/JPL/University of Arizona
Ganymede image courtesy of NASA/JPL/DLR
Callisto image courtesy of NASA/JPL/DLR

Release date

This page was originally published on Thursday, August 29, 2013.
This page was last updated on Wednesday, May 3, 2023 at 1:51 PM EDT.