Scientific convention states there are eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. On August 24, 2006, Pluto ceased to be recognised as the ninth planet, following a change in definition. But debate has reignited over Planet Nine, for a mysterious celestial body posited to be out there could claim the title for itself.
A puzzling planet could be hiding out on the distant edge of our solar system.
And astronomers have just published new information about its appearance and whether it actually exists.
Planet 9 could have five to 10 times the mass of Earth.
And planet Nine could be barrelling along an elongated orbit, peaking at 400 AU.
An Astronomical Unit (AU) is the average distance from Earth to the Sun, approximately 93 million miles (150 million km).
This orbit is also likely 15 to 25 degrees off the main orbital plain of our solar system where most planets orbit.
Planet Nine’s existence is an idea back in vogue among astronomers since it was first seriously proposed in 2014.
Proponents believe the planet exists because of patterns of objects in the Kuiper Belt, a ring of debris in the outer solar system.
This space debris clumps together in ways suggesting gravity from something significant is exerting a force on them.
And the evidence for Planet Nine’s existence is beginning to build.
A group of astrophysicists has calculated the probability of Planet Nine not existing at just 1 in 500.
And this new research indicates Planet Nine’s discovery is significantly closer than previously believed.
The likeliest alternative explanation is of an incomplete conception of the Kuiper Belt.
And this is in conjunction with objects only appearing to cluster because of bias in efforts to detect them.
And a further possibility is that the clustering results from the “self-gravity” of the Kuiper Belt acting on its own objects and does not arise from not some hidden planet’s tug.