And we're going a little deeper than in the past as well.
One of the new moons was described as a "real oddball" by researcher Scott Sheppard at the Carnegie Institution for Science, because of its tiny size, it measuring just about a half-mile (one kilometer) across. Which direction the moons swing around the planet depends on how they were first captured by Jupiter's gravitational field.
It's easy to understand why these 12 new additions had been missed so far. "We know nothing, really, more than that".
The team was using the Blanco 4-metre telescope at Cerro Tololo Inter-American Observatory in Chile, which recently got upgraded with the Dark Energy Camera.
These new moons probably formed in a place in our solar system known as the giant planet region, which is between the asteroid belt, dominated by rocky asteroids, and the Kuiper belt, dominated by icy comets. Instead, its path takes it into the realm of the nine moons that orbit in the opposite direction.
Astronomers searching for signs of a large planet far beyond Pluto have stumbled across 12 previously undetected moons orbiting Jupiter, pushing the giant planet's total to a record 79, the Carnegie Institution reported Tuesday. That means the revolve around Jupiter opposite from the planet's rotation.
Closest to the planet are the four small "inner irregulars", named Metis, Adrastea, Amalthea and Thebe. These moons include the famous Galileans: Io, Europa, Ganymede, and Callisto. Given a provisional name Valetudo (the great-granddaughter of Jupiter in mythology), it orbits prograde, but is also so far from Jupiter that its orbit is solidly among the retrograde moons!
But one moon, tentatively dubbed "Valetudo" (green), is an oddball, orbiting with Jupiter's spin but within the retrograde cluster. The more they find, the more they can narrow the area of sky where Planet Nine might be.
"With the discovery of Valetudo, it seems the collisions that broke apart the retrograde moons were between other prograde Jupiter moons, like Valetudo", Sheppard told ScienceAlert.
The other newly discovered range up to three kilometers in diameter.
The last of the team's discoveries is the strangest of them all.
"It's also likely Jupiter's smallest known moon, being less than one kilometre in diameter". Its powerful gravitational pull allows it to capture large passing objects that then collide with each other, forming dozens of new, smaller moons.
So, what of this final "oddball" moon?
So, unlike the closer-in prograde group of moons, this prograde moon has an orbit that crosses the outer retrograde moons.
"There was no eureka moment", said Sheppard, who led the team of astronomers. "Head-on collisions would quickly break apart and grind the objects down to dust".
Jupiter, it's safe to say, is one of the marvels of our solar system. Since all these objects formed from the same spinning disk of gas and dust when the solar system was born, this makes sense (and in fact was why this formation mechanism of the Sun and planets was first proposed decades ago).
Overall, this was a tough, but very rewarding discovery.