Data from New Horizons indicates water-ice on Hydra. Credits: NASA/JHUAPL/SwRI
Jan 10, 2017
Another asymmetrical moon of Pluto.
NASA launched the New Horizons mission on January 19, 2006. Nine years later, the spacecraft flew by the dwarf planet Pluto on July 14, 2015. Infrared and spectral analyses should provide data sufficient to keep planetary scientists occupied for years. An estimated full memory download should be completed sometime in the middle of 2016.
Charon was found to be almost as large as Pluto, prompting several astronomers to suggest that Pluto and Charon are a binary system. Many smaller moons, some equivalent in size to asteroids, display an asymmetrical structure with anomalous formations, like Hydra.
Hydra is an unusual moon with a potato-shape and at least two craters of substantial size. At 65 kilometers by 45 kilometers by 25 kilometers, Hydra is about the same size as Saturn’s moon, Epimetheus. If the craters on Hydra were formed in impact events the shockwaves should have destroyed it or, at least, vaporized its icy surface.
In previous Pictures of the Day, impact scenarios with other objects do not fit with observations because it was not impacts that created the craters in question. Two other moons in the Solar System, Tethys and Mimas are good examples of the problem. The putative explosions that gouged-out each of the large craters should have been powerful enough to break the moons apart.
However, Hydra’s shape and surface place it among those other small bodies in orbit around gas giant planets. Instead of a shattering force, as with an impact, electric arcs would destroy surface regolith (and ice), lifting it into space along field-aligned current channels. Since electric forces rapidly dissipate on the edges of arcs, craters with steep or vertical sidewalls and “pinched up” rims will form, looking nothing like those resulting from impacts.
Plasma discharges consist of filaments rotating around a central axis. Such discharges can cut to uniform depth, producing a flat floor. Those structures can be seen in commercial versions of electrically etched metal objects. Asteroid impacts, on the other hand, excavate holes of varying depth because impact forces decrease radially instead of being constant over the entire surface. Finally, Hydra’s distinctive shape might be due to other manifestations of electricity in space.
A Bennett pinch (z-pinch) can force matter into small volumes, squeezing it into characteristic distortions at right angles to the energy flow. Atlas, one of Saturn’s smallest moons, is a dramatic example of that potential power. Atlas is 40 kilometers long by 20 kilometers wide and rotates around its flattened plane.
The Solar System is not a neutral environment, it is electrically active. According to Electric Universe theory, it experienced a violent upheaval that saw plasma discharges and incredibly intense auroral curtains sweep across the planets. Pluto’s moons would have been hammered by electricity, bombarded with intense radiation, heated and half-melted and then blasted with lightning bolts, forming Hydra’s distinctive shape, as well as cutting its over-sized craters.
Stephen Smith
