‘Ghost Moons’ Spotted Orbiting Earth

A pair of so-called "ghost moons" have been documented orbiting our planet and they're not far from the moon we all look up and see in the night sky, according to Hungarian astronomers. 

These false moons are hazy clouds of dust that span tens of thousands of miles across but were too subtle to see with the naked eye when Polish astronomer Kazimierz Kordylewski discovered them in 1961. Kordylewski tried to convince other scientists of their existence but failed since his evidence was too faint.

However, new images published in the journal Monthly Notices of the Royal Astronomical Society support the existence of these ghost moons, also known as Kordylewski clouds. The clouds were documented by astronomers Gabor Horvath and Judit Sliz-Balogh of Budapest's Eötvös Loránd University using a specially fitted telescope in western Hungary some 60 years after their discovery by Kordylewski.

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The newly documented ghost moons orbit the Earth at about the same distance as our actual moon — around 240,000 miles on average, according to NASA — with one orbiting ahead of the moon and the other standing still at a Lagrange point.

Lagrange points are places in space where objects tend to stay put because the gravitational pull from two large masses is equal to the centripetal force needed to move a small object with them, NASA defines. 

“The idea here is that when you have a biggish object, like the Earth, orbited by a smaller one, like the moon, there are regions of space where the centrifugal force balances gravity,” astronomer Phillip Plait told NBC News MACH. “Put a much smaller object there, and it'll stay there for a long time.”

However, how much longer our ghost moons will stick around remains uncertain. While Kordylewski first came across the celestial clouds back in the 1960s, researchers believe they could dissipate in a few years.