It’s a good time to be a Europa fan—scientists continue to announce new insights into the distant, icy world. This time, the results are the result of more than a decade of European radio research.
findings, presented at the 248th meeting of the American Astronomical Society, suggested that the way Europa’s surface scatters radio waves is quite different from that seen on rocky worlds. Overall, the data are consistent with a major European radar survey that took place between the 1980s and 1990s. However, the latest observations “are more numerous and cover a wider rotation phase of Europa,” Tunhui Xie, a doctoral student at the University of California, Los Angeles, who was involved in the work, said during the presentation.
Distant icy worlds
Jupiter, the largest planet in our solar system, has 101 moons. But of particular interest to scientists are Europa, Ganymede and Callisto, which researchers suspect have underground oceans beneath their icy crusts. Of course, astronomers kept a close eye on any information they could glean from these satellites. Currently, NASA’s Europa Clipper and ESA’s Juice are on their way to take a closer look at this neighborhood.
The National Radio Astronomy Observatory (NRAO) noted in a study that there are many geological features that can tell us about something below the surface. statement on the findings. “Radio waves can penetrate ice and carry information about its internal structure and purity,” Xie added in the NRAO statement.
As the waves crash
The new study looked at 13 years of data collected between 2011 and 2024. One interesting observation was Europa’s radar albedo, which is a measure of how bright the moon appears to radar. In particular, the radar albedo of Europa was much higher than that of the planets and rocky worlds. The NRAO explained that the scattering of Europa’s radar signal is very similar to “the signature of multiple scattering within clean, porous ice.”
In addition, the team confirmed that Europa’s radar brightness remains more or less consistent, even with changes in viewing angle between the transmitter, Europa, and receiver. This trend allowed the team to set a new limit on how transparent Europa’s ice will be, and therefore how far below the surface radio telescopes can see, the statement added. This knowledge will be key to ensuring that current and future missions to Europa make the most of their time studying the distant moon.
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