Formally known as 'planet X' may actually exist.

Quote"This is a prediction. What we have found is a gravitational signature of Planet 9 lurking in the outskirts of the Solar System. We have not found the object itself," said Dr Batygin, adding that the actual discovery, if and when it happens, will be "era-defining".

link and link

This is only a prediction.

So, era-defining is more likely error-defining.

And yet several news media outlets are screaming from the rooftops that they've "discovered a new planet". I don't know whether to laugh or bellow in rage. 

If it's not sensational, it's not news!

Best evidence yet that there is/maybe a planet lurking out there. A planet is the best fit to the data, Occam's Razor and all that. Still a lot of hard work for it to be a discovery.

Opinion:

Just saying... Mathematical models are used to lie, all the time.   An example might be an unemployment rate mathematical model which is based on counting nearly a hundred million unemployed as employed, since they have stopped searching for work (which is really not there, and a waste of money to job search for anyway.)

I wonder how much money will be wasted searching for a planet which is not there, but is claimed to be further out than the former 9th planet Pluto, orbits the Sun every 10,000 years, with a gigantic mass which may demote Earth to a dwarf planet?

There's probably a better probability of finding Planet 9 than there is finding good jobs in this economy.

I can't help but think "if planet 9 was there we would have found it by now" but what do I know 

Do find stories like this interesting and am glad Snowy posted it.

That far out it would be so dim as to not reflect any light back. Unless it emits in the IR range, we'll probably never see it directly.
The only way is to infer it by it's gravitational effects. It could still be a figment of an over active imagination.

The Earth WILL always be a wanderer. Definition of Planet.

Completely agree with Data, totally enjoying this discussion started by Snowy.   My critique is friendly in tone for discussion, in response to this Planet 9 story which is widely reported in the news.   NASA seems to agree with me, I think.  And, I confess: I am biased about 8pla.net becoming obsolete.

Snowy, a friendly question, if you don' t mind...  If planet 9 does not reflect light, then why is it being considered as a part of the solar system?  

My theory is, if there is no light refection from the sun, then it is not in the solar system.  

Logic:

light=solar,

So, no light equals no solar.

It's not that the object doesn't reflect ~ANY~ light, 8pla. It's that it doesn't reflect ~enough~ light for us to detect it visually. 99.99 {insert as many 9's as you feel comfortable with} percent of the objects in both the Kuiper Belt and Oort Cloud fall under this category, and they're clearly in the Solar System, since they're orbiting around Sol (orbiting around = influenced by = in the system).

The definitions of a planet (now Pluto isn't one) are...

is massive enough to be rounded by its own gravity,
is not massive enough to cause thermonuclear fusion, and
has cleared its neighbouring region of planetesimals

Pluto fails on the last point. So if planet 9 passes the last point, it will be classed as a planet. It is orbiting our sun so is not an exo-planet. Just a long way out.

Found this too...