Jupiter’s icy moon Europa is a fascinating place and is of particular interest to astronomers for several reasons. It is known to host both water vapor and table salt, and has been suggested as being one of the locations in our solar system most likely to be hospitable to life thanks to its water-ice crust and a thin oxygen atmosphere.
NASA plans to send the Europa Clipper mission to the moon, launching in 2025, to search for subsurface lakes and evidence of recent water eruptions there. The European Space Agency’s JUICE mission to Ganymede will also perform two flybys of Europa after it launches in 2022.
Until those missions launch, however, scientists are making do with nearly 20-year-old images collected by NASA’s Galileo spacecraft in the late 1990s. By re-processing the data from this mission using modern image-processing techniques, they have been able to reveal new details in these old images.
By enhancing the colors of the images, the scientists were able to see geological features like different chemical compositions on the moon’s surface. The white-blue areas indicate pure water ice, while the red-brown sections indicate the presence of other compounds such as salts.
The bands and ridges are believed to be created in the ice surface by the movements of the hypothesized ocean beneath. The sloshing of the ocean causes movements similar to plate tectonics here on Earth, causing pressure on the surface which pushes the ice into these formations.
There are also areas referred to by the delightful term “chaos terrain” in which blocks of ice have come loose and then shifted or rotated before being re-frozen.
We’ll learn a lot more about this mysterious moon in the next decades with the launch of the new missions. “We’ve only seen a very small part of Europa’s surface at this resolution,” planetary geologist Cynthia Phillips of NASA’s Jet Propulsion Laboratory said in a statement. “Europa Clipper will increase that immensely.”
