A team of researchers scanning the farthest reaches of our solar system have inadvertently discovered 12 additional moons orbiting Jupiter. This brings the total known satellites orbiting the gas giant to an astounding 79.

Led by Scott Sheppard, a scientist at the Carnegie Institution for Science in Washington, D.C., the group found the previously unknown moons during a search for the mysterious "Planet X," a celestial body theorized to orbit at the fringes of the solar system.

"Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant solar system objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our solar system," Sheppard said in a statement.

11 normal, 1 'oddball'

The new moons, which took a year to confirm in collaboration with astronomers at the University of Hawaii and Northern Arizona University, are all very small, with each measuring no more than one to three kilometers across. Two of the moons, which were found closest to Jupiter, have prograde orbits and move in the same direction as the planet's rotation. Nine others, part of a more distant outer grouping of satellites, orbit Jupiter in the opposite direction, or what's known as a retrograde orbit.

Most unusual, however, was the discovery of a moon, the smallest ever at less than a kilometer wide, that features a prograde orbit in retrograde traffic. Labeled an "oddball" by Sheppard's team, it's likely that its small size is the result of frequent collisions with other moons traveling in the opposite direction.

"This is an unstable situation," Sheppard added. "Head-on collisions would quickly break apart and grind the objects down to dust."

In recognition of this small moon's unique place in the gas giant's expansive satellite fan club, the team have proposed that it be named Valetudo, after the Roman god Jupiter's great-granddaughter, the goddess of health and hygiene.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.