"When we discovered P4 this summer, along with possible evidence of a couple of still-fainter moons (something we need more study to confirm or reject), we began to worry about just how many tiny moons Pluto might have and whether we might have to dodge them," Stern said in his Nov. 7 mission update.
Fortunately, help is at hand. Using the four-meter Anglo-Australian Telescope in Australia, Planetary Science Institute (PSI) Senior Scientist Henry Throop and his team have been studying Pluto, watching for any signs of a ring system. However, due to its distance, Pluto's rings cannot be directly observed.
"From the ground, Pluto's rings would be too faint and too small to see directly. But occasionally, Pluto passes in front of a distant star, and that lets us study it in exquisite detail," said Throop. "As Pluto passes in front of the star, the star's light blinks out, like a moth blocking out the beam from a flashlight. We searched through the observations to try to find any hint that the star light was being blocked by rings of Pluto."