Get ready for Tyche! (Possible 9th Planet Discovered!)

Re: Possible 9th Planet Discovered!



http://www.wordforge.net/showthread.php?t=85440





(And, once again, the original thread is overlooked because of an ambiguous thread title...)

Since boths threads had a fair bit of discussion going on already, and there wasn't any time crossover in posts, I took the liberty of merging the two threads.

Re: Possible 9th Planet Discovered!

Pluto is most definitely gravitationally bound to another body. If you want to call Pluto a planet then you should call Charon one as well.

Tyche is also a goddess of commerce and trade...

Re: Possible 9th Planet Discovered!

The center of mass is much closer to Pluto though.

Re: Possible 9th Planet Discovered!

I'm all for calling both Pluto and Charon planets. If an object has become large enough to acquire a circular shape, and if it orbits the sun and not any other celestial body, it should be considered a planet.

Re: Possible 9th Planet Discovered!

The sun's hill sphere extends almost a quarter of the way to Alpha Centauri.

The so called "solar system" of planets that we are familiar with is volumetrically a tiny part of our sun's realm, just the innermost region, right on top of the sun, relatively speaking. The vast majority of the space under the gravitational influence of Sol lies outside the kuiper belt.

You'd need to go almost a full light year before the sun's gravitational influence would diminish to the point that it could no longer hold an object in stable orbit in the face of perturbations from other stars and the galactic core.

Voyager 1 has covered about one 600th of the distance, or slightly more than half a light day, in 30 years of flight. It will take almost 18,000 years to clock up its first light year.

Heliosphere, it's called. It's the boundary where the solar wind gives way to the intergalactic medium. I'd probably consider everything within that to be part of the soar system

Interstellar medium, not intergalactic. The two Voyager probes are just about out that far, IIRC.

No, HILL sphere. The heliosphere is the region within which the pressure of the solar wind prevents cosmic particles from intruding.

The hill sphere is the region around a secondary body where its gravity has greater influence on the behaviour of objects than the gravity of the primary body that the secondary is orbiting.

For example the moon has a hill sphere, with a radius of 60,000 km (37,282 miles) within which any object will be dominated by the moon's gravity more than the earth's, objects inside this sphere will orbit the moon rather than the earth. Outside the sphere, they will enter an independent orbit around earth, even though they're at the same distance from earth as the moon.

Likewise the earth has a hill sphere, with a radius of about a million miles, within which earth's gravity has more influence on the behaviour of objects than the sun's gravity, and objects will orbit the earth rather than have an indepenent solar orbit.

Then the sun itself has a hill sphere - inside it, objects will orbit the sun. Outside of it, objects will have an independent orbit around the core of the milky way galaxy.

Re: Possible 9th Planet Discovered!

If Tyche is found,

THERE ARE TEN PLANETS!

Re: Possible 9th Planet Discovered!

What rule is there that a solar system can't have a hundred "planets"?

Re: Possible 9th Planet Discovered!

It's Nature, Dan, not Logic. There's no guarantees it'll be simple.

Re: Possible 9th Planet Discovered!

"Earth-That-Was could no longer sustain our numbers, we were so many. We found a new solar system with dozens of planets and hundreds of moons -- each one terraformed, a process taking decades, to support new life...to be new Earths. The central planets formed the Alliance, a beacon of cooperation and civilization. The savage outter planets were not so enlightened and refused Alliance control. The war was devastating. But the Alliance victory over the Independents insured a safer universe. And now everyone can enjoy the comfort and enlightenment of true civilization."

Re: Possible 9th Planet Discovered!

Keeping things simple in astronomy? Not very likely.

If a body is a sphere, clears its orbit, even has moons, it is a planet, even if it messes up a nice and pretty arrangement. Pluto, Eris, Makemake, Sedna, Ceres (maybe) are full-blown planets IMO. If that means we have 45 planets in our solar system, then the IAU needs to deal with it.

We should call this one Vulcan.

I prefer Mondas!!!

Re: Possible 9th Planet Discovered!

IIRC one reason Pluto and the others aren't classified as planets any more is because of their irregular orbits. So that qualification needs to be added.

A century or so ago, "Vulcan" was a name proposed for a theoretical planet that was supposedly close to the sun, inside the orbit of Mercury.

I personally think it's time to adopt the Starfleet system for classifying planets. Earthlike is class M, something like Sedna would be class D, and so forth.

Screw that. There's arse loads of greek and roman gods to go through yet.

Once we run out of Greek and Roman gods, the Vikings want their turn, and the Hindu gods also offer a good supply.

Re: Possible 9th Planet Discovered!

Then we make Pluto the exception. It gets honor of being called a planet because we messed up.

I think we should not forget the Christian and Muslim Gods. We can have the planet Yeshua, or one of the hot Jupiter's "Mohamed".

Re: Possible 9th Planet Discovered!

Yes.

Afterall we call it a dwarf planet so we might as well go all out and call it a planet.

Why do you hate small planets?

What about the Hobbit and Elf planets? And... and... the Orc and Goblin planets?

Well, it mentions that it is 4 times the MASS of Jupiter, but says nothing about it's size. For all if it's size, Jupiter is not very dense. Tyche, if it exist, could be the same size or even much smaller than Jupiter.

I could be wrong, but I thought a brown dwarf was a failed star? That is, it failed to acquire enough mass to ignite the fusion process....