Another Star Passed Through Our Oort Cloud 70,000 Years Ago

New submitter mrthoughtful writes: According to researchers at the University of Rochester, a recently discovered dim star (Scholz's star) passed through our Oort cloud 70,000 years ago. At its closest, it was about 52,000 AU distant from Sol, or about 0.8 light-years. This is still quite a distance — Voyager 1 is about 125 AU away right now — but it's far closer than Proxima Centauri's current 266,000 AU. Still, maybe the best way to engage in interstellar travel is just to wait until the time is right.

Comments

That is close!

[Anonymous Coward]

In galactic distance, this was close and not very long ago.

I wonder how many comets it kicked out of the cloud and have cause some ruckus here on Terra.

Re: That is close!

[Anonymous Coward]

That's right about the time that the human race barely avoided extinction. Perhaps not a coincidence?

Coincidence. The paper suggests that even if it did perturb the Oort Cloud (which it probably didn't, at least, not the inner Oort Cloud), any rain of infalling comets that it kicked off will take about 2M years to get here.

Which made me think of this bit from the end of the Hitchhiker's Guide:

"Well I have got news, I have got news for you. It doesn't matter a pair foetid dingo's kidneys what you all choose to do from now on. Burn down the forests, anything. It won't make a scrap of difference. Two-million years you've got, and that's it. At the end of that, your race will be dead, gone, and good-riddance to you. Remember that. Two. Million. Years."

With a sensible species, that might serve as motivation for us to get off this rock, or at least get far enough off the rock to establish a proper planetary defense system, but I guess itâ(TM)s time for another bath. Hmph. Pass me the sponge somebody will you?

Re:That is close!

[ShanghaiBill]

I wonder how many comets it kicked out of the cloud and have cause some ruckus here on Terra.

There was a human population collapse right around that time. The population may have fallen to less than 10,000, and we nearly went extinct. This has been blamed on the eruption of Toba, an Indonesian volcano, but that may not have been the only cause.

Re:That is close!

[mcl630]

According to Wikipedia, it would take 2 million years for any comets perturbed by this encounter to get to the inner solar system.

Scholz's Star

could this be related to the genetic-bottleneck?

[suteny0r]

http://www.npr.org/blogs/krulw...

Wait till the time is right?

[Chas]

Sure. If we want to wait tens, hundreds, thousands or millions of centuries before something comes close enough. And then we have to hope that it's something useful and habitable.

And, in the mean time, we could conveniently die out.

How about "no".

I think you may have a math error (or I could have

[MaizeMan]

Here are my numbers:

20 light years = 2* 10^14 kilometers
70,000 years = 2.1 * 10^12 seconds

Therefore two stars are moving apart from year other at ~100 km/second which is right in the range of what would have been expected.

Re:The timing of technology.

[MooseTick]

"we are on track to exhaust our resources and die off on a withered old planet in the next 1,000 years or less"

The sun gives us an insane amount of nonstop energy. Do you not believe we will figure out how to effectively harness that in 1000 years time?

Re:I think you may have a math error (or I could h

[NettiWelho]

I guess I should have noticed something was off when my result suggested it was moving at over 60% the speed of light...

Good thing I am not allowed to pilot a starship.