The New Horizons probe is still years away, but scientists are certain they’ve found evidence for geysers on Pluto’s largest moon, Charon. The estimate is that Charon is resurfaced about one millimeter every 100,000 years.
This is a total change from the expectation that small outer solar system bodies would be dead and boring. Like our moon.
(A)stronomers learned of the ice deposits after discovering the spectral fingerprints of ammonia hydrates and water crystals in light coming from the moon. The findings suggest that ammonia-laced liquid water from deep inside Charon is seeping out through cracks onto the moon’s frigid surface
The researchers ruled out other possible mechanisms for the ice and concluded it must be due to cryovolcanism-the eruption of liquids and from inside the moon.
These kinds of findings make me wonder about our own moon. Human beings may have landed on it, but we only explored six sites, and even then, not for very long. Cassini has orbited Saturn for longer than all NASA lunar probes combined. It’s not like we keep a very close watch on our nearest celestial neighbor.
Above image from Mark C. Peterse / Software Bisque