Astronomers have discovered a “fraudulent” planet that floats through our galaxy, unrelated to any sun.
The “free-floating” world is slightly smaller than Earth, making it the smallest planet ever found.
But it could be one of many such deceptive planets in our Milky Way, and scientists suggest they may even surpass the stars in our galaxy.
Scientists took advantage of an astronomical phenomenon known as “gravitational microlensing” to spot a planet that unfolded, bending the light of more distant stars.
The result is an effect that is very similar to a giant magnifying glass that illuminates the light from a background star “source”
Gravitational microlensing is possible only when the astronomer’s telescope is in almost perfect alignment with the observed object and the source star.
Przemek Mroz, a postdoctoral fellow at the California Institute of Technology and lead author of the study, published in the Astrophysical Journal Letters, said: “The chances of observing a microlens are extremely small because three objects – source, lens and observer – must be almost perfectly aligned. “
The researchers studied data collected from microlens studies of the Galactic Bulge, which is the central part of the Milky Way.
They used the 1.3-meter telescope in Warsaw at the Las Campanas Observatory in Chile to collect the data.
Researchers say the newly discovered planet is the smallest deceptive world ever discovered, with models showing that it may have a mass somewhere between Earth and Mars.
Radoslaw Poleski of the Astronomical Observatory of the University of Warsaw, who co-authored the study, said: “When we first noticed this event, it was clear that it must have been caused by an extremely tiny object.
“We can rule out a planet with a star within about eight astronomical units.”
Astronomers believe that free-floating planets may have formed in the rotating disks of dense gas and dust around the stars and been ejected from their parent planetary systems after gravitational interaction with other bodies.
They say studying these objects could allow astronomers to learn more about the turbulent past of planetary systems such as the solar system.
An article describing the findings, “Candidate for planet-cheater from Earth mass, discovered in the event for the shortest time microlensing”, was published today in Astrophysical Journal Letters.
Additional reporting by the Press Association