Above: False-color composite image, showing the orbital motion of the planet Fomalhaut b.
A so-called "zombie planet" has been discovered with an orbit so extreme it has "shocked" scientists.
According to Space.com, the planet Fomalhaut B has one of the most extreme orbits ever discovered.
Fomalhaut B is a giant alien world, about three times the mass of Jupiter - and was in fact the first alien planet ever directly photographed in visible light.
It is located about 25 light years away, in the constellation Piscis Austrinus, and is under observation by teams using the Hubble Space Telescope.
The planet's 2,000-year path around its sun is highly elliptical, meaning instead of a smooth even curve around its sun it instead suffers from both extreme heat and extreme cold as it is carried both very far away and relatively close to the star's surface.
Observations said the planet comes within 4.6 billion miles of its sun, and swings out to 27 billion miles from its surface.
Its path may also lead it directly into a wide belt of debris and asteroids, which may lead to catastrophic impacts in the near future.
Above: a schematic of Formalhaut B's orbit
Researchers at the University of California said that they were shocked by the findings. They added that one explanation for the strange orbit could be that it's the result of a violent "encounter" with another planet.
"Hot Jupiters get tossed through scattering events, where one planet goes in and one gets thrown out," said Mark Clampin, of Nasa's Goddard Space Flight Center, in a statement. "This could be the planet that gets thrown out."
It is also theorised that the planet may have once had a 'dwarf planet' neighbour, or large moon, but that the two eventually collided. Other theories suggest it may have rings, and could be set for a major collision with the debris disk around Formalhaut in 2032.
The researchers said they would continue to study the planet.
Unfortuantely, the reason it's called a zombie planet is slightly less exciting than the name suggests. It's simply a reference to the fact that after its discovery in 2008 it was instead thought to be a dust cloud, until it was resurrected in 2012 after new observations.
Correction: an earlier version of this story misspelled the star Fomalhaut's name. We apologise for the error.