Hungarian Astronomers and Physicists Confirmed the Existence of Two Earth-orbiting “Moons”
After more than 50 years of supposition and controversy, Hungarian astronomers and physicists believe they have finally confirmed the existence of two Earth-orbiting “moons” entirely composed of dust.
As they outline in the Monthly Notices of the Royal Astronomical Society, the team was able to capture snapshots of these puzzling clouds hiding just 250,000 miles away, about the same distance as the moon.
Before this study, researchers inferred the presence of multiple natural companions to Earth. However, the dust clouds weren’t seen until 1961, when their namesake, Polish astronomer Kazimierz Kordylewski, spotted them. But, even at that, their presence was questioned.
Judit Slíz-Balogh, a study co-author and an astronomer at Eötvös Loránd University in Hungary explained that the Kordylewski clouds are two of the trickiest objects to detect, and though they are as close to Earth as the moon, they are largely overlooked by researchers in astronomy.
Slíz-Balogh added that it is exciting to confirm that planet Earth has dusty pseudo-satellites in orbit alongside our lunar neighbour.
According to these new results, each Kordylewski cloud is approximately 15 by 10 degrees wide, or equal to 30 by 20 lunar disks in the night sky. What this means is it takes up an area in space that is approximately 65,000 by 45,000 miles in actual size — almost nine times wider than our home planet.
The clouds themselves are gigantic, but the individual particles that they are made of are estimated to measure only a micrometre across. Sunlight reflecting off these particles makes them glow ever so slightly — just like the pyramid-shaped glow of the zodiacal light that is caused by dust scattered between the orbits of the planets.
However, these satellite clouds have stayed hidden in the darkness of space until now because they are so faint.
Gábor Horváth, another study co-author and a physicist at Eötvös Loránd University explained that it is extremely tough to spot the Kordylewski clouds against the galactic light, starlight, zodiacal light, and sky glow.
But, by using special polarizing filters on their cameras, the researchers have managed to unveil the scattered light reflecting off the individual particles within the clouds.
For many years, astronomers have suggested that it is possible for Earth to have more than one moon. There are five specific points of stability in deep space where they ascertained the moons could be situated.
These orbital points are called the Lagrange points, where the gravitational pull of two orbiting objects — like Earth and the sun — is balanced out by the centripetal force of their orbits. Here, objects stay trapped in relatively stable positions and at constant distances from both the moon and our planet.
Kordylewski first searched two of these points, L4 and L5, trying to find solid-body moons in the 1950s. However, he ended up finding the first hints of dust clouds orbiting Earth.
Dust particles get trapped in the clouds as a result of the Lagrange balancing act and then later escape as a result of slight tugs from either Earth or the moon. To refresh their dust supply, the clouds take it from all kinds of sources of interplanetary particles, such as annual events like the Perseid meteor shower. Thus, while the particles themselves may not remain very long concerning astronomical time, the clouds may have been a natural fixture since the birth of the Earth-moon system.
However, these dusty clouds could be hazardous when it comes to future space exploration.
For example, certain space missions involve parking satellites at the Lagrange points, where they expend minimal fuel to stay in orbit. That includes the upcoming James Webb Space Telescope, which is set to open at the Lagrange point L2 sometime in the 2020s.
What’s more, Horváth says that space agencies also have plans to use Lagrange points as transfer stations on an interplanetary superhighway for missions to Mars.
Therefore, Horváth also explained that the investigation of the dynamics of Kordylewski clouds could end up being most important from the point of view of space navigation safety.
Plus, if Horváth and Slíz-Balogh’s hypotheses are correct, there may be more of these roving dust clouds chasing Earth, just waiting to be found in nearby Lagrange points.
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