It may sound like something out of “Chicken Little,” but at some point in the history of Saturn’s moon Iapetus, the sky was actually falling: Scientists reported this week that an entire 800-mile-long mountain range along the moon’s equator formed after it fell from space. Iapetus doesn’t feature the telltale signs of volcanism and geologic activity that typically build mountains, which had made the existence of the bulging equatorial ridge a bit of a mystery. In a new study, researchers constructed 3-D maps of the mountain range using images captured by the Cassini spacecraft. By analyzing the shape of the triangular peaks, some up to 12 miles high, researchers concluded that the mountains were created from material that crashed onto the surface of Iapetus at some point in its history.
The researchers' hypothesis hinges on the observation that most peaks in the Iapetus range are steep, triangular peaks near their ...
