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Comment by ddalex | Hacker News Reader

I'm amazed at this coincidence, too.

It can't have had sufficiently fast impact on Earth by disturbing orbits to create impactors, given the distance.

Isn't the article mostly about how it did influence Oort cloud object orbits? Thirty-six identified.

It also discusses how there was almost certainly no impact on Earth's surface or our ancestors. Apparently the star was unlikely to even have been visible in the night sky.

...except for the potential Oort object impacts? I'm not sure they discounted that. And further: we can't track the objects that did impact something because, well, they're gone now. Statistics doesn't work well for them.

That's a minuscule number and "influenced" doesn't necessarily mean "aimed them at the Earth." There's a lot of space out there which it takes things a lot of time to move through. It takes the Earth a year to go around the Sun. And the Oort Cloud is, like, 100,000 times further away from the Sun than we are.

Even if you ignore possible asteroid impacts, there's no telling what kind of issues having red dwarf star & its brown dwarf companion so close can create.

They went into 'v' orbits, which as I understand it, means steep highly elliptical orbits that come inside the Earth's orbit? Its a lot more crowded in here.

I'm no space science maker person. So take this all with a grain of salt. But.

Halley's Comet takes 75 years to make an orbit. It goes out to about 35AU. Let's call that 1 year per AU. That rough, rough number would lead one to conclude that anything from the Oort Cloud moving at a similar speed could take, say, 100,000 years to get here even if it was aimed at us. If triggered by something 70,000 years ago, we'd still have a bunch of millenia to prepare.

Anyway. I'm sure I'm completely wrong.

There doesn't need to be any physical impactors for there to be a significant effect on climate and life. Ice ages can start and end due to tiny changes in the Earth's orbital wobble.

https://phys.org/news/2016-12-ice-ages-linked-earth-orbitbut...

So it may be, that our fate was decided by the stars.

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