New research has dealt a blow to the idea that a huge planet that has never been seen by human eyes could be lurking unseen at the edge of our solar system.
Wobbles in the orbits of objects at the edge of our solar system have led scientists to debate the existence of a mysterious unseen ‘Planet Nine’ for years.
Some researchers believe there is a planet between five and 10 times the mass of Earth at the outer edges of our solar system, where it’s very difficult for space telescopes to spot.
But University of Michigan scientists now believe the evidence for Planet Nine might be faulty – and the planet could be an illusion.
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The study suggests that instead of ‘wobbles’ in space rock orbits hinting at a gigantic planet, people have drawn a mistaken conclusion from a small number of rocks.
The researchers analysed the orbits of 14 space rocks uncovered by previous research.
Some of the rocks out there – extreme trans-Neptunian Objects (ETNOs) – have distinctly odd orbits, which led some scientists to believe there’s a planet out there.
Professor Konstantin Batygin and colleagues published a paper in 2016 predicting the existence of Planet Nine, and new space rocks found since that point have seemed to confirm their conclusions.
The University of Michigan team said that, instead, there was significant selection bias due to the way ETNOs are found.
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The researchers wrote in their paper: "Because ETNOs follow highly elliptical orbits, and their brightness decreases like 1/r4, they are almost always discovered within a few decades of perihelion.
"Moreover, telescopic surveys observe a limited area of the sky, at particular times of year, to a limited depth. These effects result in significant selection bias."
To analyse the results of three previous surveys, the researchers simulated detections of a larger population of space rocks.
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They wrote: "In essence, a survey simulator simulates detections of a model population of Solar System bodies by using a survey's pointing history, depth, and tracking criteria.
"This allows for the computation of a survey's selection function for a given population, which enables us to account for bias, and therefore understand the true underlying populations."
Instead of suggesting the existence of a large, rocky planet, the new results suggest there is nothing out there at all, the researchers say, saying that they, "thus conclude that this sample provides no evidence for angular clustering".
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