Using reflected light from Jupiter to photograph Ganymede’s night side
During Juno’s June 7, 2021 close fly-by of Ganymede, scientists used its instruments to obtain the first good image of a part of this Jupiter moon. What made the achievement especially amazing was that the area photographed was only lit by the reflected light from Jupiter, the equivalent of its “earthshine.” From the paper’s abstract:
On 7 June 2021, the Juno spacecraft flew within about 1,000 km of the surface of Jupiter’s largest moon, Ganymede. The Mission used their sensitive navigation camera to photograph the moon’s dark side where it was lit only by scattered sunlight from Jupiter. This new imaging approach revealed multiple surface features, including a patchwork of different surface textures (such as grooved terrain), several craters, and ejecta deposits. These features had not been visible in images collected by previous spacecraft.
The picture to the right is from figure 2 of the paper, cropped and reduced to post here. It shows a region on Ganymede that in the earlier images had shown few details because the lighting was poor and thus features were not easily discerned (as can be seen by the inset in the lower right). In the new picture, the only light was reflected from Jupiter, and its low angle brings out the surface topography.
During Juno’s June 7, 2021 close fly-by of Ganymede, scientists used its instruments to obtain the first good image of a part of this Jupiter moon. What made the achievement especially amazing was that the area photographed was only lit by the reflected light from Jupiter, the equivalent of its “earthshine.” From the paper’s abstract:
On 7 June 2021, the Juno spacecraft flew within about 1,000 km of the surface of Jupiter’s largest moon, Ganymede. The Mission used their sensitive navigation camera to photograph the moon’s dark side where it was lit only by scattered sunlight from Jupiter. This new imaging approach revealed multiple surface features, including a patchwork of different surface textures (such as grooved terrain), several craters, and ejecta deposits. These features had not been visible in images collected by previous spacecraft.
The picture to the right is from figure 2 of the paper, cropped and reduced to post here. It shows a region on Ganymede that in the earlier images had shown few details because the lighting was poor and thus features were not easily discerned (as can be seen by the inset in the lower right). In the new picture, the only light was reflected from Jupiter, and its low angle brings out the surface topography.