Scientists Baffled By Earth-Sized Rogue Planet Freely Floating In Milky Way

Astronomers are on a constant lookout for planets similar to Earth that can potentially harbor life.?

In the pursuit of such distant planets, scientists have now discovered a new rogue planet that is sized between that of Earth and Mars. The newfound planet free floats somewhere in the Milky Way galaxy.

(Representative Image: NASA)

Scientists at the University of Warsaw claim to have discovered the smallest free-floating planet found to date. The planet is free-floating as it does not orbit any particular star and is expected to be adrift somewhere in the?middle of Milky Way.

The scientists discovered the new planet using an interesting technique called microlensing - an effect wherein the warped spacetime around a planet magnifies a background star’s light briefly as the planet aligns between the star and Earth.

Microlensing is important as it is the only way of discovering rogue planets. This is because such planets do not have a star of their own, meaning they “don't emit any visible radiation, so they cannot be detected using traditional astrophysical techniques,” Przemek Mroz, one of the authors of the research paper, explains on Twitter.

In the case of the new planet candidate, the microlensing event was observed to be ‘the most extreme short-timescale microlens discovered to date.' Termed OGLE-2016-BLG-1928 in a recent research paper published in The Astrophysical Journal, the event lasted for just 41.5 minutes. This means that the new planet is one of the smallest, if not the smallest, rogue planet ever discovered.

NASA

From the observations, the scientists predict in their research paper that the planet “may be a Mars- to Earth-mass object.” They base this on the unknown distance of the planet and predict that it might be closer to Mars in size because of the Gaia proper motion measurement of the planet.

The authors also rule out the the presence of stellar companions or stars up to the projected distance of 8.0 astronomical unit from the planet. More than the planet, the study proves to be a working example of the fact that microlensing can be used to detect free-floating planets.