Space & Astronomy

New evidence of elusive 'Planet Nine' discovered by astronomers

By T.K. Randall
May 5, 2025 ·  5 comments

Is there another world in our own solar system ? Image Credit: NASA / Caltech/R. Hurt (IPAC) Nobody knows exactly where it is, how big it is or if it even exists at all, but when researchers at the California Institute of Technology revealed in 2016 that the existence of a ninth planet in our solar system was a very real possibility, the hunt for this enigmatic new world began in earnest.

Believed to be up to ten times the mass of the Earth and with an orbital period of up to 20,000 years, Planet Nine, if it exists, will be situated somewhere beyond the orbit of Neptune.

Finding it, however, is like looking for a tiny fraction of a needle in a very big haystack.

Now, though, a new study headed up by astronomer Terry Long Phan of the National Tsing Hua University in Taiwan has identified what could be the strongest evidence yet of its existence.

The findings concern two infrared surveys - one by the Infrared Astronomy Satellite (IRAS) in 1983 and another by the Japanese Space Agency's AKARI spacecraft in 2006.Phan's team had been looking for objects that had changed position between the two surveys and ultimately spotted one particular object that seemed to have moved in the intervening time by an amount consistent with predictions about the potential orbit of Planet Nine.

While the finding is not enough on its own to extrapolate the object's full orbit, it does offer a tantalizing glimpse at what could actually be a whole new undiscovered planet in our solar system.

"Once we know the position of the candidate, a longer exposure with the current large optical telescopes can detect it," Phan told Space.com.

If this object really is Planet Nine, then it would need to be more massive than Neptune.

Ultimately, without further data, it's currently impossible to know for sure if it really is the elusive undiscovered planet or not.

Source: Space.com | Comments (5)

Tags: Planet Nine