|That's no (ordinary) moon! It's an electrostatic field generator!|
Hyperion is porous and icy, with a bizarre, sponge-like appearance. Its surface is continuously bombarded by ultraviolet light from the sun and exposed to a rain of charged particles -- electrons and ions -- within the invisible bubble generated by Saturn's magnetic field, called the magnetosphere. The researchers think Hyperion's exposure to this hostile space environment is the source of the particle beam that struck Cassini.This raises the question of whether other bodies in the solar system have similar properties. Imagine the possibilities in your own games, stories, projects for objects that might pose a Bermuda Triangle-like danger to explores caught unawares. First they're caught in a natural tractor beam (of sorts) and then pulled down into the cavernous interiors. "Moon-as-monster" has a neat ring to it, is all I'm saying!
Measurements made by several of Cassini's instruments during a close encounter with Hyperion on September 26, 2005, indicate that something unexpected took place in the charged particle environment around the spacecraft. Among those instruments, the Cassini Plasma Spectrometer (CAPS) detected that the spacecraft was magnetically connected to the surface of Hyperion for a brief period, allowing electrons to escape from the moon toward the robotic probe.
Image: NASA/JPL/Space Science Institute
More about the Cassini mission: