Astronomers have discovered a “free-floating” planet in the Milky Way that is slightly smaller than Earth and gravitationally unrelated to any star.

Scientists say it is the smallest “rogue” planet ever discovered.

In 2011, the team discovered 10 celestial bodies the size of Jupiter and without parent stars in 10 astronomical units. An AU is equal to the distance between the Earth and the Sun.

Researchers believe that when most known planets orbit a star, the galaxy will be enriched by rogue planets, which may be larger than the number of stars in the Milky Way.

Scientists have used an astronomical phenomenon known as “gravitational microlensing” to discover the planet, which manifests itself by bending the light of more distant stars.

The result is like a giant magnifying glass, which shines from a background “source” star and reveals the presence of a massive object.

Gravitational microlensing is possible only when the telescope of an astronomer is perfectly aligned with the object and source star.

Pressmec Mros, a postdoctoral scholar at the California Institute of Technology and lead author of the study, published in the Astrophysical Journal Letters, said: “Microlensing is very likely to be observed because the source, the lens and the observer must be perfectly compatible. ”

The researchers examined data collected from microlensing surveys of the galactic bulge, the central part of the Milky Way.

The data was collected using a 1.3-meter Warsaw telescope at the Las Campanas Observatory in Chile.

Researchers say the newly discovered planet is the smallest rogue world ever discovered, with models suggesting that there may be a mass somewhere between Earth and Mars.

Radoslo Poleski, an astronomical observatory at the University of Warsaw, who co-authored the study, said: “When we first discovered this event, it was clear that it was a very small object.

We can rule out a planet with one star within eight astronomical units. ”

Astronomers believe that free-floating planets may have formed on the rotating disks of dense gas and dust around stars, and that they would be ejected from their parent planetary system after gravitational interaction with other bodies.

They say that by studying these objects, astronomers can learn more about the turbulent past of planetary systems such as the Solar System.