The Earth has a nearly perfect circular orbit. Any collision with another planet would have pushed it off its orbit and caused it to at the very least created a more elliptical orbit that likely would have made the swings in temperature more deadly for life on Earth.
This entire article is science fiction.
There is a lot of evidence of a big collision, but that's a very good question anyway!
I guess the interactions with other planets and asteroids change the orbit to a more circular one. I couldn't find a serious source that confirm, and not even a non-serious, so I'm still curious, very curious.
Anyway, there is a good theory that Jupiter formed at 3 AU and moved later to 5 AU and (very slowly) caused havoc in all the outer solar system https://en.wikipedia.org/wiki/Formation_and_evolution_of_the... So the initial orbits are not fixed in stone.
How can it be science fiction if most scientists currently believe this?
[0] https://en.wikipedia.org/wiki/Giant-impact_hypothesis#Possib...
Let me give you a pro life tip. When someone comes up with an extraordinarily complicated scenario or hypothesis and it can’t answer a very simple straightforward question, it most certainly means that the the hypothesis is wrong.
It’s all science fiction.
Sure, there are still questions. But the questions for all the other explanations of the Moon's origin at even bigger. You can be skeptical, but until you have a better theory that accounts for all the evidence, you don't get to dismiss it as "science fiction". Not if you want to be taken seriously anyway.
Here's a life pro tip: The correct guideline for a theory is "as simple as possible and no simpler. The real world is complicated. Complicated things happen all the time.
It's also ignoring the fact that we likely did have additional planets, but after interactions with other planets with nearby orbits, they would have been either ejected out of the solar system entirely, caused to collide, or herded into more circular (non-overlapping) orbits.
This is why Pluto is not a planet.
The reason is that it was observed "too soon" because of its interaction with Neptune's orbit. Once we realized there were plenty of such objects in the range of Neptune's orbit but we also realized that these were not fully formed planets, we invented the term of dwarf planet, so Pluto was demoted to that status, which it shares with many other objects in the far out orbit.
So, it was just a classification thing. We could have also said all those others are also planets.