It’s a good time to be a fan of Europa, as scientists continue to report new insights into the distant, icy world. This time, the results came from a radio study of Europe that lasted more than a decade.
results, foot At the 248th meeting of the American Astronomical Society, she notes that the way Europa’s surface scatters radio waves is distinctly different from those seen on rocky worlds. Overall, the data are consistent with the major radar study of Europe, conducted between the 1980s and 1990s. However, the latest observations are “more numerous and cover a much broader rotation phase of Europe,” Tunhui Shih, a doctoral student at the University of California, Los Angeles, who was involved in the work, explained 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 contain subterranean oceans beneath their icy crusts. Naturally, astronomers were paying close attention to any data they could collect from these moons. As of now, NASA’s Europa Clipper and ESA’s Juice are on their way to study this neighborhood up close.
However, there are only a few geological features that can tell us about anything much below the surface, as the National Radio Astronomy Observatory (NRAO) noted in a report. statement On the results. “And this is where things like radar come in,” Shih added in the NRAO statement, saying that “radio waves can penetrate the ice and carry information about its internal structure and purity.”
Waves also bounce
The new study looked at 13 years of data collected between 2011 and 2024. One fascinating observation concerns Europa’s radar albedo, which is a measure of how bright the moon is to radar. Specifically, Europa’s radar albedo was much higher than that of planets and rocky worlds. The way Europa scattered the radar signal closely resembles “the hallmark of multiple scattering within clean, porous ice,” the NRAO explained.
Furthermore, the team confirmed that the brightness of Europa’s radar remained fairly constant, even with shifts in the observing angle between the transmitter, Europa, and the receiver. The statement added that this trend allowed the team to effectively set a new limit on how transparent Europe’s ice is, and thus how far radio telescopes can see beneath the surface. This knowledge will be key in ensuring that current and future missions to Europa make the most of their time studying the distant Moon.
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