In 2016, scientists spotted signs which offered a hint that there is a huge, unseen world lurking at the edge of our solar system – ‘Planet Nine’.
Now an army of citizen scientists might have tracked it down – with four possible candidates which could be the missing planet, and which are now being investigated by scientists.
The giant, hidden planet is thought to be 10 times more massive than Earth – and on an orbit which takes 10,000 or 20,000 years to go round the sun.
Australian National University (ANU) is now investigating the four unknown objects – pinpointed during a planetary search launched on BBC Stargazing Live by Dr Brian Cox.
Dr Brad Tucker, lead researcher, said 60,000 people from around the world had taken part – classifying four million objects.
Dr Tucker said: ‘We’ve detected minor planets Chiron and Comacina, which demonstrates the approach we’re taking could find Planet Nine if it’s there.’
Earlier this year, scientists have found more signs that the unseen planet is out there – in the form of the wonky orbits of two ‘extreme trans Neptunian objects’ (ETNOs), according to researchers from the Instituto de Astrofísica de Canarias (IAC) in collaboration with the Complutense University of Madrid.
The orbits of asteroids 2004 VN112 and 2013 RF98 suggest that the two were once a binary asteroid which separated after an encounter with a planet beyond the orbit of Pluto.