The idea that extraterrestrial life could exist in our Solar System got one of its earliest boosts almost half a century ago when NASA spacecraft first photographed the more intricate details of Jupiter’s icy moon, Europa.
The Voyager 2 mission captured a puzzlingly smooth surface in July 1979. It also found what astronomers have dubbed “crop circles.” On Earth, people attribute supernatural forces or alien visitors to these mysterious patterns formed from depressions in a field of wheat. But “crop circles” is also a name astronomers have given the puzzling, faint troughs on Europa’s surface. No, scientists don’t think they were made by intelligent alien life, but they do think they could be a sign that Europa might have the right ingredients to support life. If surface ice were moving around, it would create these troughs. And that morphing ice would exist because of hydrothermal activity, which could theoretically support life.
