Two new possible planets in our Solar System?

a reply to: rickymouse

of course...

its because the unknown can be frightening.

In the grand scheme of the universe it took over 500 years for the Catholic Church to apologize over that whole earth being the center of the universe issue. When looking at time 500 years is nothing on the time line.

originally posted by: snowspirit
a reply to: JadeStar

Lol. Actually i love change. But school was a long time ago, and I used to know that there was 9 planets.
Now there's 8 planets and 5 dwarf planets. What's bad is that I had to Google that

It could change again, that's okay I guess.
New discoveries are always welcome.

It probably will change, because astronomers think there could be dozens or even hundreds of dwarf planets. That was the reason for making the category of "Dwarf Planet", and including Pluto and Eris in that group.

If Pluto and Eris (which is larger than Pluto) would be classified as planets, then there may soon be a large number of things called Planets -- considering that finding trans-neptunian objects is getting easier with better equipment. If Pluto was still the 9th planet, then Eris would be the 10th planet. Sedna may have a claim about being a planet, and maybe Quoaor. When some other kuyper-belt object is discovered that's as big as Eris or Pluto, then it, too may have been able to have been called a planet.

Pluto should have never been a planet in the first place, and now that they found so many other Pluto-like objects (that are not Planet-like objects), that only serves to reinforce the idea that Pluto is not a planet.

When Pluto was removed from the list of major planets in the Solar System, I thought that it was the correct decision. It seemed to be simply one of the largest members of the Kuiper Belt, since many other smaller objects have orbital characteristics similar to Pluto. In addition, Pluto simply isn't massive enough to gravitationally "clear it's orbit". However, what really annoys me about the change in the classification status is this ridiculous "dwarf planet" category that they have added. This includes Pluto, Eris and a handful of other Kuiper Belt objects, and also Ceres (the largest asteroid).

Frankly, this just makes the Solar System a more complicated place than it should be. Why the hell do we want to class Ceres as a "dwarf planet" when it should be more logically classed as the largest asteroid? Why does it need to be classed as a dwarf planet?

I am starting to wonder whether the IAU made a major mistake that day.

the logic was it was layered and had the internal structure of a planet if i recall correctly. asteroids don't have a core, mantle and crust. ceres does and so does the first object the dawn probe went to. only the crust and mantles was obliterated on that one.

presumably they think pluto and eres have a internal structure that justifies them being called planets (dwarf or not.) I guess they just didn't want to call all the dwarf planets legitimate planets but the new system is even more messy if you ask me.

For me, the strongest reason not to call Pluto a planet, is that its orbit crosses the orbit of Neptune, sometimes taking it closer to the Sun than Neptune. No planet should have such an orbit, planetary orbit should be clearly separated from each other.

a reply to: Mogget

Yeah -- I'm not sure what to make of Ceres just yet. However, it does seem like an interesting place, with some exciting exploration times ahead. The Dawn spacecraft will arrive at Ceres this March, orbiting at about 5900 km, and will orbit very closely (700 km) in subsequent months.

Ceres is thought to possibly have a thick water-ice layer covering it, although with a thin layer of dust on top of that. I suppose in that respect it could be thought of as similar to Europa, but without the tidal forces from Jupiter's gravity that keeps Europa's sub-surface water in liquid form. Ceres is also thought to have a tenuous, yet measurable, atmosphere.

Hopefully as Dawn explores Ceres over the next several months, it will find it to be a more interesting place than just a space rock. We'll see.

a reply to: wildespace

obviously the "problem here" is that we cant determine how big an object needs to be to be considered a "planet".
some planets are much bigger than others.
they dont even all consist of the same materials
some moons are not hollowed out chucks of space debris but intelligently produced
there are billions of different places to "reside" in our Galaxy and Beyond
it just takes forever to get there

originally posted by: wildespace
For me, the strongest reason not to call Pluto a planet, is that its orbit crosses the orbit of Neptune, sometimes taking it closer to the Sun than Neptune. No planet should have such an orbit, planetary orbit should be clearly separated from each other.

This is the issue when planet formation and primordial history may include migrating gas giants, ejected rogue terrestrial class planets and colliding terrestrial class planets. one of our planets rotates backwards and another has its pole pointing nearly into the ecliptic. Earth has been theorized have had a collision with a Mars Sized planet resulting in the moon. and i believe Mars itself is believed to had such a collision. The first "asteroid" object the dawn probe went to was really the core of a murdered worldlet.

Now i am not saying i buy Velikovsky's theories but there were a whole heck of a lot of shaking, moving and migration going on in the primordial Sol System. it is only by chance we don't now have a weirder set of orbits for our planets.

originally posted by: blacktie
a reply to: wildespace

obviously the "problem here" is that we cant determine how big an object needs to be to be considered a "planet".
some planets are much bigger than others.
they dont even all consist of the same materials
some moons are not hollowed out chucks of space debris but intelligently produced
there are billions of different places to "reside" in our Galaxy and Beyond
it just takes forever to get there

oh it's even worse than that. there is a "rogue planet" with an "exo-moon" that may alternatively be a red dwarf star and a planet.

MOA-2011-BLG-262 the object with no positive ID. in the table at the bottom of this wiki page: en.wikipedia.org...

may be a red dwarf... wut?

originally posted by: stormbringer1701

originally posted by: wildespace
For me, the strongest reason not to call Pluto a planet, is that its orbit crosses the orbit of Neptune, sometimes taking it closer to the Sun than Neptune. No planet should have such an orbit, planetary orbit should be clearly separated from each other.

This is the issue when planet formation and primordial history may include migrating gas giants, ejected rogue terrestrial class planets and colliding terrestrial class planets. one of our planets rotates backwards and another has its pole pointing nearly into the ecliptic. Earth has been theorized have had a collision with a Mars Sized planet resulting in the moon. and i believe Mars itself is believed to had such a collision. The first "asteroid" object the dawn probe went to was really the core of a murdered worldlet.

Now i am not saying i buy Velikovsky's theories but there were a whole heck of a lot of shaking, moving and migration going on in the primordial Sol System. it is only by chance we don't now have a weirder set of orbits for our planets.

I'm talking about now, not about the period of planetary formation and migration. (Back then, they weren't even proper planets but protoplanets)

We can look at our planets today, and see that Pluto is truly the odd one out.

originally posted by: blacktie
a reply to: wildespace

obviously the "problem here" is that we cant determine how big an object needs to be to be considered a "planet".
some planets are much bigger than others.
they dont even all consist of the same materials
some moons are not hollowed out chucks of space debris but intelligently produced
there are billions of different places to "reside" in our Galaxy and Beyond
it just takes forever to get there

When did I mention anything about size (or other properties)? I only mentioned the orbit.

Besides, the official IAU definition doesn't talk about size or composition. It talks about whether the oject in question has "cleared its neighbourhood" of smaller objects, i.e. whether it is gravitationally dominant in its orbit.

And since Pluto crosses the orbit of Neptune, it is quite clearly _not_ gravitationally dominant in its own orbit.

originally posted by: wildespace

I'm talking about now, not about the period of planetary formation and migration. (Back then, they weren't even proper planets but protoplanets)

We can look at our planets today, and see that Pluto is truly the odd one out.

yes but it is possibly down to chance that we have the orderly orbital configuration we do. there are other possible stable configuration even if planets ended up crossing orbits in one dimension. i am not certain we should be Sol centric when creating astronomical definitions and classes.

Please continue in the recently posted existing thread on this topic.

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