reply to post by MamaJ
stereologist pretty much summed it up.
Can there be objects out there that we don't know about? Sure, and of course.
Can there be an object out there that has a 3600 year orbit around the sun, but who's orbit is eccentric enough to bring it in the inner solar system
that we just have not detected yet? The answer to that is again: sure!
But then you need to go with the other questions too:
If both the above questions hold true, could this be a very large object such as a star, brown dwarf, giant gas giant?
In that case, the answer would be no. Not with a eccentric orbit that brings it into the inner solar system. Even if we could not see or detect it for
some reason, the affect it would have on the sun and the planets we can see would be dramatic. Every 3600 years it would change the orbits of the
inner planets (throwing some right out of the solar system) and give the sun a large "wobble" that we would see. So even if we couldn't see it, we
would see the effects of it's very large mass.
What if it was a much smaller object? With much less mass?
If that were the case, then I would have to say "Nibiru" or "Planet X" is a lot more plausible. If it's mass is small enough, it would not affect
the orbits of the inner planets. But it would have to be a very small object. Meaning dwarf planet or smaller.
In that case: yes it would be hard to detect, may not be detected easily if it were still out past the Kuiper belt region, and may not interact with
anything that we can see because it's so small.
However, keep in mind, if it were that small......then it's not going to cause any dramatic "Earth Changes". It's just too small.
Also keep in mind, even if it were that small, but is going to arrive in December of this year, then it would have to be about as far as the asteroid
belt right now, and then it would be visible to anyone with a pair of bonoculars at this point, just like the asteroid Ceres which is very small,
under 1,000 miles across and anyone can out out and see it in the sky at night.
Unless you buy into the whole "It's populated by advanced aliens that keep in cloaked (and some how negate gravity)" or "it's made of of matter
than only emits or reflect IR" (which is still funny since we can detect IR just fine).
As for the periodic ELE theory, as stereologist said, that theory has pretty much fallen out since no one has been able to show that ELE's have a
perodicity and I've never seen any proof that the Earth undergoes a ELE every 3,600 years.