A 9th planet in our solar system? Scientists finally find a potential candidate to ‘replace' Pluto
The empty seat on the 9th row might just be filled!
There possibly is a 9th planet after all (and a
replacement for Pluto
)!
Researchers have *finally* found a candidate for the hypothetical
Planet Nine
, which could be an undiscovered giant planet way out in our solar system.
Read on to find out more about the potential candidate!
The 9th planet!
It's been almost two decades since our solar system lost its 9th planet. Pluto was officially reclassified from a planet to a
dwarf planet
by the International Astronomical Union (IAU) in August 2006. While Pluto orbits the Sun and is large enough to be spherical due to gravity, it is not big enough to gravitationally dominate its orbital region, meaning other objects share its path in the Kuiper Belt. Pluto was reclassified as a dwarf planet in 2006 by the IAU because it failed to meet the third criterion for being a planet: it did not "clear its neighborhood" around its orbit.
Nearly two decades after that, astronomers claim that they may have found new evidence that points to a celestial body that could be a possible candidate as "Planet Nine," according to a new paper, which has been accepted for publication in the Publications of the
Astronomical Society of Australia
but not yet peer-reviewed.
What do the researchers say?
Astronomers engaged in the search for a hypothetical
ninth planet in our solar system
have identified a promising candidate situated well beyond Neptune, according to a recent preprint study. This finding may represent the first substantial evidence of the long theorized Planet Nine, which, if confirmed, would be a large, yet-to-be-discovered world orbiting the sun at a considerable distance. However, the prospect of Planet Nine remains a debated topic within the scientific community, and skepticism surrounds the new findings.
The potential planetary candidate was detected while researchers analyzed archival data from two decommissioned satellites: the Infrared Astronomical Satellite (IRAS), operational in 1983, and the AKARI satellite, which functioned from 2006 to 2011. The team was specifically looking for distant objects exhibiting slow movement characteristic of a large planet's orbit. After dismissing known celestial objects, they focused on a shortlist of candidates and ultimately identified what they referred to as "one good candidate." This candidate appeared as a consistent dot in infrared images from both satellites, indicative of a single object.
Study lead author Terry Phan, a doctoral student in astronomy at the National Tsing Hua University in Taiwan, expressed excitement over the discovery, noting its motivational impact on the research team. Their findings were shared on the preprint server arXiv on April 24 and have been accepted for publication in the journal Publications of the Astronomical Society of Australia.
Who is the potential candidate for the 9th planet?
According to the paper, the hidden candidate is likely the size of Neptune and is so far away that it could take between 10,000 and 20,000 years to orbit the sun.
The criteria to be a Planet:
For a celestial body to be classified as a planet, the IAU defines, it must meet three criteria: it must orbit a star, it must be massive enough to have achieved hydrostatic equilibrium (meaning it is round or nearly round), and it must have cleared its orbital neighborhood, meaning it is the dominant gravitational body in its orbit.
Is Planet Nine the replacement for Pluto?
Despite this progress, some experts remain unconvinced. Notably, Caltech astronomer Mike Brown, who originally proposed the Planet Nine hypothesis alongside a colleague in 2016, has expressed doubts regarding the infrared signals' connection to the elusive planet. Brown analyzed the orbit of the candidate and concluded that its tilt—approximately 120 degrees from the Solar System's plane—deviates significantly from the predicted tilt for Planet Nine, which should be around 15 to 20 degrees. This discrepancy suggests the object may not significantly influence the orbits of other known planets.
The predictive position of Planet Nine is designed to account for the irregular orbits observed among some objects in the Kuiper Belt at the outer edges of our solar system. However, many researchers contest the notion that an undiscovered planet is responsible for these anomalies, and direct observational evidence for Planet Nine's existence remains elusive.
If Planet Nine does exist, predictions indicate that it would be considerably larger than Earth, orbiting the sun in a distant and unusual path. The vast distance from the sun makes detection particularly challenging, complicating efforts to confirm or refute its existence.
Follow-up observations are necessary to refine the orbit of the identified candidate. Brown has suggested that if the infrared signal indicates a planet, it would contradict the existence of the originally hypothesized Planet Nine, as their orbits would likely destabilize each other.
Evidence of ninth planet found in solar system
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The Hindu
a day ago
- The Hindu
Is it a moon? Is it a dwarf planet? Well, it's Charon, and it could well be both!
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The technology available at that time meant that even the best photographs of it hardly revealed anything. What's more, these six images – acquired in pairs over three nights in the month between April 13 and May 12 – were labelled as 'defective.' Odd blobs The reason why these pictures were labelled thus owed to the fact that they revealed Pluto to be oddly elongated. Viewing them under a microscope, Christy noticed that the fuzzy blob that was to be Pluto stretched in a northern direction in two of those pairs, while the final pair showed a southward direction. The defects were attributed either to atmospheric distortion or improper optical alignment in the telescope used for observations. After ruling out an explosion on Pluto as an unlikely explanation – especially as it lasted a month – Christy searched for other plausible reasons. There was a chance that Pluto itself was irregular in shape. Or could there be an unseen moon, even though one of his former professors, celebrated Dutch-American astronomer Gerard Kuiper, had searched for exactly the same decades earlier without any success? When Christy went over to the archives to check through older plates from 1965 onwards, there it was... the same elongation. What's more, all these images had also been dismissed as defective on every occasion. Correct conclusions Christy and Harrington, however, realised that they were onto something. By reviewing all the images with the elongations, they were able to state that the bulge occurred with a predictable frequency. This frequency of the unseen moon's orbital period – 6.4 Earth days – matched with what astronomers believed to be Pluto's rotational period, suggesting a synchronously locked binary system. The duo ruled out other possible reasons for the bulge and concluded correctly that Pluto had another companion at a distance of 19,640 km. The discovery of 'S/1978 P1' was announced by them through the International Astronomical Union (IAU) on July 7 and their findings were published in the Astronomical Journal. What started out as reviewing six defective images, served as the seeds for a whole new discovery. As Christy himself once pointed out, 'Discovery is where the scientist touches nature in its least predictable aspect.' What's in a name? As the discoverer, Christy wanted to exercise his rights for naming Pluto's companion. And he had his mind set on naming it after his wife. The Naval Observatory he worked for had suggested the name Persephone, the wife of Hades. Hades, the god of the underworld in Greek mythology, was the equivalent of the Roman god Pluto after which it is named. As luck would have it, Christy came across a reference to Charon, a boatman who ferried the dead across a river in the underworld to Hades. 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Economic Times
15-06-2025
- Economic Times
Pluto-like planet discovered: How big is it and how far is it from Earth?
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Time of India
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- Time of India
Pluto-like planet discovered: How big is it and how far is it from Earth?
In a significant breakthrough, astronomers have detected a Pluto-like planet situated far beyond the known boundaries of the solar system. Identified as 2017 OF201 , the icy celestial body may represent the largest object discovered in the outer solar system in over a decade, reigniting interest in the unexplored expanses beyond Neptune. Pluto Like Planet With an Extraordinary Orbit Classified as an extreme trans-Neptunian object (TNO), 2017 OF201 is believed to be around 700 kilometers (435 miles) in diameter—about half the size of Pluto. Though smaller than the famous dwarf planet, its location and orbital characteristics have startled researchers. The object's aphelion, or farthest distance from the Sun, is more than 1,600 times Earth's orbital distance, while its perihelion, the nearest point to the Sun, is roughly 44.5 times that of Earth—comparable to Pluto's orbital reach. 'This suggests a highly elliptical and unusual orbit,' noted Dr. Sihao Cheng from the Institute for Advanced Study, Princeton, which led the discovery, as mentioned in a report by Forbes. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Beckham Swapped Heels. Walked More. Noticed The Difference. dailybuzzreport Try Now Undo The planet takes approximately 25,000 years to complete one revolution around the Sun, hinting at a dramatic cosmic history. A Decade's Largest Solar System Discovery Discovered using a combination of data from the Dark Energy Camera in Chile and the Canada-France-Hawaii Telescope, the celestial body was captured over seven years and 19 different exposures. Astronomers suggest that if the object's size is verified via radio telescopes, it will earn the title of the largest newly discovered planetary body in the outer solar system since the early 2010s. Live Events 2017 OF201 joins a short but significant list of massive TNOs, which includes Eris, Pluto, Haumea, Makemake, and Gonggong. It further challenges previous assumptions about the sparsity of large bodies in the far-flung regions of the solar system. Possibly Ejected from the Oort Cloud According to the researchers, the extreme orbit of 2017 OF201 suggests a tumultuous past. It may have been gravitationally ejected by one of the gas giants early in solar system history, potentially reaching the Oort Cloud—a distant shell believed to host countless icy bodies—before being pulled back inward. 'This is a classic case of a planetary body that didn't just form where it now resides. Its path tells the story of encounters, ejections, and returns,' said Dr. Yifan Yang, a collaborator on the study, as mentioned in a report by Forbes.. Solar System May Host Hundreds More The Kuiper Belt , the donut-shaped region beyond Neptune, was once thought to be relatively empty. However, the discovery of 2017 OF201 raises fresh questions about what lies beyond. 'The fact that 2017 OF201 was detectable while spending just 1% of its orbital period near the inner solar system implies that there could be hundreds of similar-sized objects we simply haven't detected yet,' Dr. Cheng added. A Renewed Push for Outer Solar System Exploration This discovery provides renewed impetus for studying the Pluto-like planet category and the solar system's unexplored boundaries. It may also guide future missions akin to NASA's New Horizons , which flew past Pluto in 2015 before entering deeper Kuiper Belt territory. Astronomers emphasize that while humanity has explored deep space with cutting-edge instruments, the very edges of our own cosmic neighborhood remain largely uncharted territory. FAQs What is 2017 OF201? 2017 OF201 is an icy, Pluto-like celestial body classified as an extreme trans-Neptunian object (TNO). It was recently discovered in the far outer regions of the solar system and could be the largest such object found in over a decade. How big is 2017 OF201? The object is estimated to be around 700 kilometers (435 miles) in diameter, which is approximately half the size of Pluto.
