A telescope has discovered a new world on the edge of the Milky Way – potentially confirming the ‘Planet X’ theory.
Beyond Neptune, a smaller ‘ninth’ planet has been identified in the Kuiper Belt.
If the object is confirmed as an actual planet, it would make it the ninth in our solar system, following Pluto’s downgrade to a dwarf planet.
The potential planet, nicknamed ‘Ammonite’, was discovered by scientists using the Subaru Telescope at Japan’s National Astronomical Observatory, who published their findings in Nature Astronomy.
Ammonite has probably been in a stable orbit for more than 4,000,000,000 years, they said.
‘If Planet Nine exists, its orbit should lie even farther out than previously predicted,’ according to a news release from the observatory.
‘Furthermore, the existence of Planet Nine would also need to explain why Ammonite’s orbit does not cluster with those of the other sednoids.’
In late May, scientists hunting for Planet Nine, the elusive planetary body that could change our understanding of the solar system, found something.
Planet X is a hypothetical planet seven times the mass of Earth tucked just behind Pluto. Despite possibly being the fifth most massive planet, scientists have never tracked the white whale of astronomy down – that is, if it even exists.
But a trio of American scientists trying to find the elusive gas giant discovered a new planet… of sorts, a dwarf planet called 2017 OF201.
What is Planet Nine?
The search for a ninth planet in our solar system has been going on for a century.
The evidence for it that hunters have long clung to is how six objects – dwarf planets and icy balls – have been discovered in the vastly empty outskirts of the solar system.
Bizarrely, they huddle together as they orbit, as if something a gassy behemoth of a planet were shepherding them, said Imo Bell, astronomer at the Royal Observatory Greenwich.
They told Metro: ‘Some astronomers believe that proving the existence of this planet would explain the behaviour of many other eTNOs with highly elliptical orbits clustered on one side of the Sun.
‘It’s thought that Planet Nine, with a mass of about five Earths, would explain the confined orbits of these eTNOs.’
A dwarf planet is an object large enough that its gravity squishes it into a round shape, but not large enough to ‘clear the neighbourhood’ of other celestial bodies.
According to a study, which has not been peer-reviewed, 2017 OF201 is roughly 430 miles across, three times smaller than Pluto.
The object is an extreme trans-Neptunian object (eTNO), a minor planet that orbits the Sun far beyond Neptune.
So far away, in fact, OF201 would take 25,000 Earth years to complete a solar lap. Its orbit even swings out into the Oort Cloud – a sphere of icy comets a trillion miles from the Sun.
OF201 can only be observed from Earth 0.5% of the time, making its closest approach to us in 1930 and won’t do so again until 26,186.
The International Astronomical Union’s Minor Planet Center added 2017 OF201 to its database last week. Five other dwarf planets are officially recognised: Pluto, Eris, Ceres and two others beyond Neptune, Haumea and Makemake.
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