New Discovery, Earth Officially Has Three Moons

Illustration of three moons.
Bruce Rolff / Shutterstock

How many moons does Earth have?

This is a question that could be found on a science test at any elementary school in the world. The right answer yesterday is now the wrong answer today. While Luna remains the only moon we can see when we look up at a clear night sky, it is not alone — and hasn’t been for some time. Andrew Fazekas of National Geographic provides the details.

“Earth’s moon may not be alone. After more than half a century of speculation and controversy, Hungarian astronomers and physicists say they have finally confirmed the existence of two Earth-orbiting “moons” entirely made of dust.”

Long before the official discovery, researchers inferred the existence of these moons. It wasn’t until 1961 that a Polish astronomer named Kazimierz Kordylewski was able to catch a questionable glimpse. The article continues.

“The Kordylewski clouds are two of the toughest objects to find, and though they are as close to Earth as the moon, are largely overlooked by researchers in astronomy,” says study coauthor Judit Slíz-Balogh, an astronomer at Eötvös Loránd University in Hungary. “It is intriguing to confirm that our planet has dusty pseudo-satellites in orbit alongside our lunar neighbor.”

Each cloud moon is about nine times the width of earth. While the moons are extremely large, the individual particles are estimated to be one millionth of a meter across. That makes the formation rather difficult to see, only made visible by special camera filters.

The gravitational pull of two massive objects such as the Earth and the Sun is balanced by the centripetal force of said orbits. These points of balance are known as Lagrange points. Generations of astronomers have suspected moons could be hiding out in some of those points.

In 1950, Kordylewski searched L4 and L5 for solid moons. That is when he first detected hints of orbiting dust clouds. The clouds are unstable, constantly swapping out their material. Like the human body, they remain constant while ever changing.

The more curious minds among us collectively ponder deep space, other star systems, and life elsewhere in the galaxy. We watch space operas like Star Trek and imagine the lives and loves of people living out their lives beyond the simple boundaries of our single planet.

Yet discoveries like the two hidden dust moons remind us of just how much we have yet to learn in our own stellar neighborhood. Pluto is a planet, and then it isn’t a planet. There is nagging speculation of planet that didn’t make it into the science books you used as a child, tentatively named Planet X, according to CNN.

Now, Earth has three moons. While we’re still patiently waiting to beam up and warp out, there is still a lot to see and learn right where we are.