Comments on: Star’s close approach 70,000 years ago pinned to cometary orbits

By: pzatchok

pzatchok — Sun, 25 Mar 2018 18:51:40 +0000

I wonder if we could gravity assist a colony ship up to a speed fast enough to use something like this as the next step to getting to a viable solar system?

Obviously this one is way to far away now.

By: wayne

wayne — Thu, 22 Mar 2018 00:18:15 +0000

“How fast are we moving through the universe?”
https://youtu.be/ZX0zcEZnIsA
(2:03)

By: Localfluff

Localfluff — Wed, 21 Mar 2018 14:10:40 +0000

If a foreign star raced through our solar system at hypervelocity speeds, it would shake the Earth. And change our calendar. But at 1/10 of the speed of light, such a star would be “here” as in planetary distances, only for hours. Looking at distances and stuff, one realizes that this never has and never will happen.

By: ken anthony

ken anthony — Wed, 21 Mar 2018 13:54:12 +0000

It is a wondrous thing to think about.

By: Localfluff

Localfluff — Tue, 20 Mar 2018 19:47:56 +0000

Well, please disregard my fake math in the post above. “Hyper”velocity stars are much more potent. Moving at real fractions of the speed of light. Or a thousand times faster than Voyager now leaving the building.

By: Localfluff

Localfluff — Tue, 20 Mar 2018 19:42:29 +0000

@geoffc Just 17 km/s, I'm afraid. And New Horizons is slower. Here is a graph that shows the huge influence of gravity assists on the Voyagers' speed from the Sun. The fastest star known (to me) moves at a speed of 1,200 km/s relative to the Milky Way center and are concluded to be intergalactic. Just a couple of thousand years from Andromeda at that velocity.

By: geoffc

geoffc — Tue, 20 Mar 2018 18:43:59 +0000

That implies it is doing 1/3500th of light speed. Which is about 85 Km/s. 85,000m/s. Still faster than any human probe. Voyager is at 35,000 I think.

Be fun to be able to accelerate a star even a small one to that kind of speed. Hmmm, how much energy would that take? (Way too much!)

By: Localfluff

Localfluff — Tue, 20 Mar 2018 18:39:43 +0000

It seems strange that such a very nearby star wasn’t discovered until a few years ago. A huge ball of plasma fusion nuking its way through billions of years, still almost invisible in our neighborhood. Is something else hiding out there?