WHy do some atsronomers believe hat there is another planet beyond pluto?

Question

Links if possible, thank you very much

Answer 1

You're probably talking just about our solar system, but beyond it astronomers have found a total of 304 extrasolar planets orbiting other stars.

Answer 2

They know there is at least one plutoid beyond Pluto because it has been discovered, named (Eris), and classified along with Pluto as a plutoid rather than a planet.

Plutoids are celestial bodies in orbit around the Sun at a semimajor axis greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighborhood around their orbit. Satellites of plutoids are not plutoids themselves, even if they are massive enough that their shape is dictated by self-gravity. The two known and named plutoids are Pluto and Eris. It is expected that more plutoids will be named as science progresses and new discoveries are made.

The dwarf planet Ceres is not a plutoid as it is located in the asteroid belt between Mars and Jupiter. Current scientific knowledge lends credence to the belief that Ceres is the only object of its kind. Therefore, a separate category of Ceres-like dwarf planets will not be proposed at this time.

That leaves us with the question, what the heck is Ceres if it is a dwarf planet, but there is no separate dwarf planet classification.

Answer 3

i think i know what your talking about, its just some ice planety thingy behind it

Answer 4

It does not classify as a planet, but Eris is beyond the orbit of Pluto and was discovered in 2003.  It's actually bigger than Pluto.  It's one of the main reasons Pluto got busted to dwarf planet or planetoid.

http://www.gps.caltech.edu/~mbrown/plane...

Answer 5

While no serious astronomer believes there is a "real" planet beyond Neptune, There are many planet like objects beyond Pluto, in fact, this is eactly why Pluto was recently redefined to be a minor planet. Large asteroids are found in the region called the " Kuiper Belt"

http://en.wikipedia.org/wiki/Planet_X#Ob...

http://en.wikipedia.org/wiki/Planet_X#Pl...

Astrobuf

Answer 6

As others have mentioned (136109) Eris is known to be out there, though of course like Pluto it is not a planet according to the current IAU definition.

If you are refering to the recent news article about some astronomers proposing the existence of an object nearly the size of the Earth in an orbit a bit further out than Eris then you can read their detailed reasons by downloading the PDF available at the site mentioned below.

Basically the authors of the article have conducted computer simulations of the development of the outer parts of the Solar System and conclude that the existence of an approximately Earth-sized object in an orbit ranging from about 100 AU to 250 AU helps to explain certain features of the orbital distribution of objects in the Kuiper Belt and beyond.  All these objects have only been discovered in the last 15 years (the first was (15760) 1992 QB1) so this is an area of active research.  There may be other explanations for the observed distribution and the observed distribution may be slanted by the classes of object we've been able to observe up to now.  However, if the proposed object does exist we do have the capability of finding it although it may take some time to search all the parameter space.

Answer 7

Well, because there's the Oort Cloud and the Kupier Belt out beyond Pluto, and both of those places have many many rocky objects, some of which might meet the criteria to be called a planet (or more probably, a dwarf planet).

Answer 8

Why ask why?  You want links.  How about you providing some links to the "some astronomers believe ..." pages?  

There is lots of stuff out in the far reaches of the solar system beyond Pluto, some of it aggregated into planet-like bodies the size of Pluto or even larger.  This region of space is referred to as the Kupier belt.