> its orbit takes it from just beyond the orbit of Saturn (10.9 AU) all the way out to the Oort Cloud

It looks like it currently orbits the sun.

Ah, for some reason I read the original message as some new dwarf planet was outside our solar system and had a trajectory towards it. Thanks for the clarification.

According to the link, the outgoing aphelion will be almost 40% more than the previous one, so I wouldn't assume it's going to orbit indefinitely.

That seems awfully weird. Is that something that things orbiting the sun normally do?

My intuition is that anything with a really eccentric orbit (10s to 10s of thousands of AU) has more of a chance of passing through many gravitational fields that change its orbit.

I suppose that makes sense... if something is in an orbit that's flattened down until it's only slightly off from being a straight line in and out, then any very slight perturbations could really affect how close it comes to the sun on the next pass.

The sun moves too a little bit, due to the pull of the planets. Maybe it's enough to make a difference?

It is from our solar system. It has just a very eccentric orbit, but it was always orbiting the Sun.

But for interstellar objects, the answer is always "no". Unless it passes very close to some object that there's an orbital slingshot (or a collision, the odds of both are basically zero), interstellar objects always move away.

For the most part, conservation of energy dictates that bodies in orbit will stay in orbit, and bodies transiting the system will exit it. Think of it like a ball rolling down a hill, then back up a hill of equal height. By rolling downhill, it gains enough velocity to make it back up the hill.

There are exceptions, of course. An asteroid passing through an atmosphere may be slowed down by friction (aerobraking), and be captured in orbit. Passing near another orbiting body, the interloper can be sped up or slowed down (gravity assist). But both of those require getting pretty close to a planet, and space is really big (citation needed), so it's unlikely that it would be captured.

Edit: Looks like I had the same misinterpretation, that it was a rogue planet rather than an Oort/Kuiper belt object.

According to TA it is orbiting the sun. The closest point out will be at beyond Saturn's orbit, the farthest will be 30-50k AU. Of course, there are some error bars on these numbers that I can't interpret, and given that it orbits that far out, its orbit might actually be influenced by neighboring stars as well.

It amazes me that it last visited the "inner" solar system 2.75 million years ago. And after perturbations its next approach will be 4.5 million years from now. Its aphelion distance will be about 0.8 lightyear.

If it manage to do a gravity assist maneuver around some existing planet, it might. Probability of such is very low, I believe. Moreover, I think if there was any chance, scientists already knew about it. If they keep silence, then no, there are no chances.