As far as baby names go, P4 is both unimaginative and lacking character. Nevertheless, that’s what NASA’s calling the tiny little rock recently discovered orbiting Pluto, at least until the International Astronomical Union (IAU) settles on something with a bit more personality.
At just 8 to 21 miles across, P4 is smaller than a city on a mote of dust suspended in a sunbeam, but like all objects crossing or approaching the orbit of Neptune, it’ll get a wicked awesome mythological name. The IAU will try to honor the decision of SETI’s Mark Showalter, who discovered P4. What’s his choice? “This is a topic under discussion,” Showalter told Life’s Little Mysteries, but mentioned that Cerberus “seems to come up most.”
Cerberus is the three-headed watchdog of Hell in Greek mythos, and brother of many-headed serpent Hydra, another of Pluto’s moons. Unfortunately, Cerberus has already been bestowed upon an asteroid. This doesn’t rule out its availability for P4, though–the alternate Greek spelling, Kerberos, is still up for grabs. If the SPACE.com readers’ poll has its way, though, we’ll be calling the little guy Mickey.
[source] [image: NASA, ESA, and M. Showalter (SETI institute)]