The Most-Distant Solar System Object Discovered (cnn.com)

Rick Zeman writes: Astronomers in Hawaii have discovered the furthest object in our solar system, a dwarf planet aptly named "Farout." This planet is 100 times farther than Earth is from the sun (120 AU from the sun) and is thought to be composed of ice. The object is so far away that researchers estimate it probably takes more than 1,000 years to make one trip around the sun. For reference, Pluto is 34 AU away and takes about 248 years to orbit the sun. Eris, the next most distance object know, is 96 AU from the sun.

Comments

Farthest post

[Anonymous Coward]

Farthest post!

Voyager 2

[hcs_$reboot]

Voyager 2 is also at 120 AU from earth, and is said to have left our solar system. So "farout" is outside?

Re:Voyager 2

[Anonymous Coward]

I think when you find new planets orbiting our sun at some distance our solar system is by definition expanded out to that distance.

Re: Voyager 2

[Anonymous Coward]

It has entered intersellar space (beyond the heliopause) but is still within the solar system. There are likely objects part or the solar system that are as far as 1,000 au away from the sun, almost 1/4 of the way to the nearest star.

Re: Voyager 2

[hackertourist]

That depends on your definition of "solar system". The 'end' Livescience are talking about is the heliopause, where the environment is no longer dominated by the solar wind. The gravitational influence of the Sun reaches much further than that. The Oort cloud is thought to stretch out to about 1 ly from the sun, beyond that the Sun is no longer the dominant gravitational force.

This discovery shows it's silly to use definitive statements like "end of the solar system" when objects that are clearly part of our solar system are found beyond 122 AU.

Re:Voyager 2

[Anonymous Coward]

This "outside" nonsense is a bit of media hyperbole.
The oort cloud is part of our solar systems, or more specific, part of our stars "significant influence".
The oort cloud is so big it touches the nearest stars oort cloud. It's essentially doing the dirty deed with it, it is so close.

The supposed end these people were talking about was the termination of the solar winds, which doesn't define THE end (it shouldn't!), just the end of one particular facet of the solar system.
The better actual end of the solar system is when the suns gravity is no longer the dominating force, which puts it anywhere up to half-way between here and Alpha Centauri. The exact value isn't known for obvious reasons (not been there, barely discovered bodies, etc.)
At this distance, objects cease Sol orbit and instead just intermingle with other objects in the outer oort cloud regions, probably ending up smashed at some point, if not hurled towards the inner solar system and becoming an orbiting body over the next few billion years depending on speed.
The big issue on the exact termination point inside of the oort cloud is determining where gravity is still, overall, the defining force. Given there is so much crap out there that was pushed out in the early solar system, it could be that stuff is just slowly moving away from us at speeds we can't reliably measure. Or, it could be that gravity is pulling in some of these smaller objects all the time but the solar winds can overpower that when they get in far enough. Where that ends is the real question.
The inner oort cloud is still (and should be) very much considered part of our solar system, just like the very far reaches of our atmosphere are considered part of it, beyond a certain density of air where it is then considered space and particles just fly off from the solar winds because gravity can no longer hold on to it.
You'll certainly not be breathing at the far edges (inner solar system edge), but it is still our atmosphere.

Re:Voyager 2

[icejai]

Voyager 2 left the heliopause, but technically, things can be in interstellar space and still be gravitationally bound to the/our sun.
"Being part of the solar system" might depend more on gravity, instead of being in the heliopause.

Re:Voyager 2

[in10se]

That's a question of semantics. Voyager has left our heliosphere. This new planet is still held by the sun's gravity, so it would be part of our solar system even if it is outside the heliosphere.

! AU = Distance Of The Earth To The Sun

[Crashmarik]

Not to get picky here but if it's 120 AU away from the Sun that 120 times the distance of the Earth from the Sun not 100

Re:! AU = Distance Of The Earth To The Sun

[ls671]

Hehe, interesting but I think you have this backward. Earth seems closer in North hemisphere winter right now:
https://en.wikipedia.org/wiki/...
https://en.wikipedia.org/wiki/...

Also, I think this might change through the eras since I can't figure out a relation between the axis of the Earth and its orbit position so it seems random to me so far.

Re:Sedna?

[SqueakyMouse]

From space.com:

To be clear: The record Farout now holds is for the most-distant solar system body ever observed. That doesn't mean no other objects gets farther away from the sun than 120 AU. In fact, we know some that do. The dwarf planet Sedna gets more than 900 AU away on its highly elliptical orbit, for example, and there are probably trillions of comets in the Oort Cloud, which lies between about 5,000 AU and 100,000 AU from the sun.