Astronomers have had a major breakthrough as they spotted the smallest “rogue planet” floating around the Milky Way. A rogue planet is a planet that is unattached to the star. In simple words, it is not orbiting around a star like Earth and other planets in our solar system orbit around the Sun.

As per these astronomers, this exoplanet’s mass which is just 10 per cent of our planet. It is expected that there is an abundance of planets like these floating around the galaxy. However, they are not easy to detect because of their free-floating nature.

“Our discovery demonstrates that low-mass free-floating planets can be detected and characterized using ground-based telescopes,” Andrzej Udalski, said in a statement. Udalski is the co-author of a new study that made the discovery and also the principal investigator of the Optical Gravitational Lensing Experiment (OGLE) project.

The technique used to discover the rogue planet was ‘gravitational microlensing’. Astronomers can observe the foreground objects that pass in front of distant stars in the background.

“Chances of observing microlensing [events] are extremely slim because three objects — [light] source, lens and observer — must be nearly perfectly aligned,” said the lead author at the California Institute of Technology in Pasadena, Przemek Mroz,. “If we observed only one source star, we would have to wait almost a million years to see the source being microlensed.”

So far, scientists have been able to discover more than 4,000 exoplanets using the ‘transit method’ under which they look for dips in brightness. Another technique called ‘radical velocity’ tracks movements caused by the planet’s gravitational pull.

Earlier this week, an earth-sized exoplanet that showed promising life-supporting signs. The TOI-700d orbits an M-dwarf star which is much cooler than the Sun while the planet itself is located in the absolute vicinity of the star.