The newly-remastered images show the icy surface of Europa, the sixth of Jupiter’s moons and the fourth largest, in enhanced color.
This map shows locations where each image of Europa’s surface was captured by Galileo during its eighth targeted flyby of Jupiter’s icy moon. Image credit: NASA / JPL-Caltech.
All three high-resolution images were captured along the same longitude of Europa as NASA’s Galileo spacecraft flew by on September 26, 1998, in the eighth of the spacecraft’s 11 targeted flybys of the icy moon.
The images revealing features as small as 460 m (1,509 feet) across were taken through a clear filter in grayscale (black and white).
Using lower-resolution color images of the same region from a different flyby, technicians mapped color onto the higher-resolution images.
This image of an area called Chaos Transition shows blocks that have moved and ridges possibly related to how the crust fractures from the force of Jupiter’s gravity. Image credit: NASA / JPL-Caltech / SETI Institute.
Enhanced-color images like these allow planetary scientists to highlight geologic features with different colors.
Such images don’t show Europa as it would appear to the human eye, but instead exaggerate color variations to highlight different chemical compositions of the surface.
Areas that appear light blue or white are made of relatively pure water ice, and reddish areas have more non-ice materials, such as salts.
“We’ve only seen a very small part of Europa’s surface at this resolution,” said Dr. Cynthia Phillips, a planetary geologist at NASA’s Jet Propulsion Laboratory.
“NASA’s future Europa Clipper spacecraft will increase that immensely.”
This image of an area called Crisscrossing Bands shows ridges, which may form when a crack in the surface opens and closes repeatedly. In contrast, the smooth bands shown here form where a crack continues pulling apart horizontally, producing large, wide, relatively flat features. Image credit: NASA / JPL-Caltech / SETI Institute.
Planetary researchers study high-resolution images of Europa for clues about how the surface formed.
At an average of 40-90 million years old, the surface we see today is much younger than Europa itself, which formed along with the Solar System 4.6 billion years ago.
The long, linear ridges and bands that crisscross Europa’s icy surface are thought to be related to the response of the moon’s surface crust as it is stretched and pulled by Jupiter’s strong gravity.
This image shows chaos terrain where blocks of material have shifted, rotated, tilted and refrozen. Scientists use this as a puzzle for clues about how the surface has changed. The area is called Chaos Near Agenor Linea for its proximity to the wide band of that name at the bottom of the image. Image credit: NASA / JPL-Caltech / SETI Institute.
Ridges may form when a crack in the surface opens and closes repeatedly, building up a feature that’s typically a few hundred yards tall, a few miles wide and can span horizontally for thousands of miles.
In contrast, bands are locations where cracks appear to have continued pulling apart horizontally, producing wide, relatively flat features.
Areas of so-called chaos terrain contain blocks that have moved sideways, rotated or tilted before being refrozen into their new locations.
To understand how they might have formed, scientists study these blocks as if they are jumbled puzzle pieces.
