Perhaps because they still feel bad about taking away Pluto's official planet privileges in 2006, scientists using the Hubble Telescope discovered a fifth moon orbiting the former 9th planet. The moon, creatively titled S/2012 (134340) 1, or P5, is irregular in shape and roughly 6-15 miles across.

Scientists are nerding out over the find because it could help explain how Pluto and its other moons came into existence.

According to one idea, all the moons are relics of a collision between Pluto and another large icy object billions of years ago.

"The moons form a series of neatly nested orbits, a bit like Russian dolls," said Mark Showalter from the Seti Institute in Mountain View, US, the leader of the team that discovered the new moon.

Just under a year ago, scientists discovered Pluto's fourth moon, P4. An unmanned NASA spacecraft called New Horizons is currently en route to Pluto, with an expected flyby sometime in 2015; the spacecraft should provide the first up-close details of Pluto, which, according to the BBC, "is so small and distant that even Hubble can barely see the largest features on its surface."

As for those terrible names, the AP reports that:

Mark Showalter of the SETI Institute said names for the new moon and last year's discovery will not be proposed until the team finishes analyzing the Hubble data in case there are more hidden moons.

Showalter said he favors names that go together - like the mythological Greek couple Orpheus and Eurydice.

"If we happen to find more moons, then we will have to pick a different story from Greek mythology," he said in an email.

Let's hope they get their act together soon.

[photo via NASA]