Astronomy and Conjuring

It is commonplace, and even expected, for evolutionists to hide behind their lack of knowledge with "Science of the Gaps" (where maybe someday, "science" will find the answer, but we'll just keep on believing anyway), or the explanations that contain words like "maybe", "perhaps", "scientists think", "scientists speculate", "it could be" &c.

solarsystem.nasa.gov
However, it is more difficult to accept the use of a more complex explanation known by scientists as "making stuff up". When it comes to astronomy, the sky's the limit (heh!).
It has always been impossibly difficult for astronomers to realistically explain how galaxies, stars, and planets might have formed through natural processes. To prop up their naturalistic theories, they will sometimes invent unobserved structures, such as the Oort cloud for comets.
More recently, astronomers conjured an unknown massive planet that was supposedly responsible for placing Uranus and Neptune in their unique paths around the sun. However, the fictional planet is still a woefully insufficient cause for today's planetary orbits. 
The extra planet was proposed because cosmologists have had a miserable time trying to model the evolution of the solar system's four gas giant planets from a huge, unorganized dust disc. The recent modeling effort, partly funded by the National Science Foundation, defined a "successful" attempt very loosely.
You can finish reading "Mythical Planet Doesn't Solve Orbit Origins" here.