Astronomers venturing into the far reaches of our solar system have reported a promising candidate for the long-sought-after ninth planet, often referred to as Planet Nine.
The discoveries were made possible through the analysis of archived satellite data, which led researchers to a curious dot in a few infrared images.
This dot has shown movement consistent with that of a large, distant planet, exciting researchers and fueling hopes for a breakthrough in the enduring mystery of Planet Nine.
The study, led by Terry Phan, a doctoral student in astronomy from National Tsing Hua University in Taiwan, was published on the preprint server arXiv on April 24 and later accepted for inclusion in the Publications of the Astronomical Society of Australia.
Phan expressed his excitement about the discovery, stating, “I felt very excited. It’s motivated us a lot.”
Despite the allure of this new candidate, skepticism has emerged within the scientific community regarding its connection to Planet Nine.
Mike Brown, an astronomer from Caltech, who co-proposed the Planet Nine hypothesis in 2016, remains unconvinced that the newfound infrared signals correspond to the elusive planet.
Although Brown did not participate in the study, he calculated the orbit of the mysterious dot and found it would be tilted approximately 120 degrees from the solar system’s plane.
This significant tilt is inconsistent with the predicted tilt of around 15 to 20 degrees for Planet Nine, suggesting that this object would be orbiting in a direction unlike any known planets, which tend to be aligned on a similar plane.
Brown emphasized that while this mismatch doesn’t eliminate the possibility of Planet Nine’s existence, it indicates that the new candidate is unlikely to be the planet theorized to influence the orbits of objects in the Kuiper Belt.
He remarked, “I don’t think this planet would have any of the effects on the Solar System that we think we’re seeing.”
The prospect of Planet Nine largely emerged from the need to explain the unusual orbits of certain bodies in the Kuiper Belt, located at the far edges of our solar system.
Yet, debates persist within the scientific community regarding the legitimacy of these orbits and whether they can be accurately attributed to an undiscovered planet.
As it stands, there remains a lack of direct observational evidence for Planet Nine, which further complicates the conversation surrounding its existence.
Should Planet Nine eventually be discovered, researchers anticipate it to be substantially larger than Earth and to exhibit an atypical orbit that stretches billions of miles beyond Neptune, the currently recognized eighth planet in the solar system.
This immense distance from the sun poses a challenge for astronomers attempting to detect the planet, which is why proving or disproving its existence has proven elusive.
In their quest, the research team diverged into the data archives of two decommissioned satellites: the Infrared Astronomical Satellite (IRAS), operational in 1983, and the AKARI satellite, active from 2006 to 2011.
They focused on hunting for distant objects that would exhibit slow movements between sets of collected data, mimicking how Planet Nine would behave if it indeed orbits the sun.
After filtering through known celestial bodies captured in the data, the researchers narrowed their focus to a shortlist of potential candidates.
Upon careful analysis of the images, they surfaced with what they identified as “one good candidate,” characterized by consistent colors and brightness across two sets of images.
The findings indicate that this could be a singular object captured by both satellite missions, yet follow-up observations are necessary to ascertain the full details of the object’s orbit.
Brown asserted that if the signal indeed points to a planet, then it could not share its orbit with the originally hypothesized Planet Nine, as each would disrupt the other’s gravitational dynamics.
This revelation raises the possibility that the new candidate could represent an entirely different celestial body which could, in turn, challenge the existing Planet Nine hypothesis.
The discourse surrounding Planet Nine, or any other potentially undiscovered planet in the solar system, is unsurprisingly contentious.
However, the year 2025 may mark a pivotal moment in the ongoing search, possibly leading toward clearer conclusions about the existence of these elusive planetary candidates.
image source from：https://www.livescience.com/space/planets/astronomers-identify-first-good-candidate-for-controversial-planet-nine-deep-in-our-solar-system
