If this planet takes 20, 000 years to orbit the sun, surely it's not a gas giant?

Unless it's subjected to significant tidal forces the planet would be ateast frozen on the surface?


Also to put it into context, this planet has 0.01% the luminosity of Pluto and can only be observed via gravitational disturbances, 200 - 300 AU away from earth.Try and find that...

Yet since they know where to look, they're reasonably confident that they can detect it quite soon. I wouldn't be surprised if there are several instruments attempting to capture it, but I know that they're at least looking with this http://www.naoj.org/Projects/HSC/ on Mauna Kea.

That's no new planet---it's a space station.

Which is a silly distinction because from everything I've read, the only thing that prevents Pluto from being considered a regular planet as opposed to a dwarf planet is its location. If Earth was where Pluto was, it wouldn't clear its neighborhood either, and would thus not be considered a planet.

I was checking this out. That's pretty cool!

Location makes no since because we have a dwarf planet within the inner ring of plannets. It's due size from my understanding.

Maybe the James Webb Space Telescope will be used some to try and spot it? It's the successor to Hubble, and has more deep view purposes, but could probably be used to look for nearby objects as well.

I agree with fantasyjunkie. It's really cool.

Yes and no. It's about size in that once an object gets to a certain size, it becomes spherical due to its own gravity, but the third determining factor (which is where things like Pluto and Eris fail) is all about location.

The three things that are used to determine whether or not an object is a planet (according to the IAU) are:

1. It orbits the Sun.

2. It has sufficient mass to achieve hydrostatic equilibrium (meaning that it is big enough that its gravity makes it roughly spherical)

3. It has "cleared its neighborhood."

That third point means that a body has become the dominant gravitational influence in its orbital zone, and there are no other large bodies inside the orbital zone that aren't its own satellites or similarly under its gravitational influence.

That's where location comes into play. Basically, the further a planet is away from the sun, the harder it becomes for it to clear its neighborhood. If you put Pluto where Mercury is, it would be a planet. But because of its location, it isn't considered one.

It becomes truly ridiculous when you consider the fact that half the planets still called planets in our solar system, Earth, Mars, Jupiter, and Neptune, haven't cleared their neighborhoods. Jupiter's orbital zone is home to more than a million asteroids. If Neptune had cleared its neighborhood, Pluto wouldn't be where it is.

The clearing its neighborhood argument is like saying your cat is a cat as long as it isn't on a chair. If it's on a chair, it must be considered a mongoose.

So if they find a planet 20 times the size of the Earth... would the IAU argue that it isn't a planet because it hasn't "cleared it's neighborhood" or will they just say it is simply because of how big it is?

I think it depends on what it's made of. If it's a gas giant like Jupiter, they probably wouldn't try and label it a "dwarf planet." But by their own definition, if a planet that massive hadn't cleared its neighborhood, it couldn't be classified as a planet, regardless of its composition. On the other hand, they didn't strip other planets of their status because of their definition, so who knows?

I forgot to mention that another flaw with the IAU's definition is that it only applies to this solar system, meaning that if Pluto was discovered in literally any other solar system in the universe, the IAU's definition wouldn't preclude it from planetary status, even if it hadn't cleared its orbit there either.

Well hopefully they have images before JWST launches in a couple years. But yeah, I'm sure they will use it especially if they can spot it with terrestrial telescopes and confirm it. One of its missions is planetary observation, both exoplanets and inside the solar system, simply because our atmosphere is opaque at certain frequencies so we can do better spectroscopy (for example) from space. More info http://jwst.nasa.gov/origins.html.

Coincidentally, I worked (in a very very very small capacity) on both the JWST and the Hyper Suprime Cam. Go figure.