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Space Is Full of Planets, and Most of Them Don't Even Have Stars

forbes.com

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Re: Space Is Full of Planets, and Most of Them Don't Even Have Stars

#41

Post by nabla9 »

lev99 wrote: post #32
itronitron wrote: post #26

Interstellar travel now seems a lot more hazardous than it did before. To quote one of my TAs in college, "it's the stuff you can't see that gets you" ...

The article states that planets may outnumber stars 100,000 to 1. The Milky Way has 4E^11 stars. It has an upper estimate of 4E^16 planets. It has a lowest estimate diameter of 100kly. It has an estimated thickness of 2kly. It's lower estimate volume is 63,000 kly^2. ----------------------------- If planets are uniformly disrupted (they surely aren't), there are ~17 planets in every cubic light year. Sure, that's a h…

> ~17 planets in every cubic light year.

The change of hitting one while traveling one light year is in the order of 10e-16.

Re: Space Is Full of Planets, and Most of Them Don't Even Have Stars

#43

Post by TheOtherHobbes »

gnulinux wrote: post #36
itronitron wrote: post #26

Interstellar travel now seems a lot more hazardous than it did before. To quote one of my TAs in college, "it's the stuff you can't see that gets you" ...

I did no math to confirm this but intuitively it seems incredibly unlikely to hit a rogue planet if you shoot something to a star randomly. How's it any different than shooting something inside Solar system and accidentally hitting an asteroid?

Collisions are not the problem. Gravitational perturbation is the problem.

If most planetary systems are anything like this one, planetary orbits are quasi-stable, and a visitor could easily destroy that stability.

It would take a while for that to play out - anything from months for a very unlikely very near miss, to many millennia for a distant visit.

Re: Space Is Full of Planets, and Most of Them Don't Even Have Stars

#45

Post by bencollier49 »

King-Aaron wrote: post #42
ataturk wrote: post #13

Why would we visit forbes.com to learn about astronomy?

Because it just so happens that Forbes has an article about astronomy.

Yes, but it's probably rubbish clickbait. They locked me out of the site when I opted out of tracking. Good riddance and I look forward to their receiving a hefty fine from the EU for GDPR non-compliance.

Re: Space Is Full of Planets, and Most of Them Don't Even Have Stars

#46

Post by everdev »

nabla9 wrote: post #38
itronitron wrote: post #26

Interstellar travel now seems a lot more hazardous than it did before. To quote one of my TAs in college, "it's the stuff you can't see that gets you" ...

Planets can be detected by their gravity field. Collision with planet sized object in space would be extremely rare. Even if you would travel blind it would be very unlikely that you would hit star or plant while traveling trough galaxy.

Well, if there's not much around it, it might be hard to detect it's gravitational effects.

I'd imagine you could detect it blocking a circular patch of sky more easily and from farther off than you could detect the gravitational pull on your spacecraft.

Just don't steer twords the black disc and you'll be fine.

Re: Space Is Full of Planets, and Most of Them Don't Even Have Stars

#47

Post by hamilyon2 »

itronitron wrote: post #26

Interstellar travel now seems a lot more hazardous than it did before. To quote one of my TAs in college, "it's the stuff you can't see that gets you" ...

Actually, one could refuel reactive mass by mining those planet if delta v is favorable. Reactive mass deficit is one of biggest problems with interstellar travel. Suddenly, I think interstellar travel is a bit less impossible.

Re: Space Is Full of Planets, and Most of Them Don't Even Have Stars

#48

Post by pmontra »

hermitdev wrote: post #14
beamatronic wrote: post #9

Earlier quoted context omitted.

Could you provide an example? I don’t recall such an episode.

I dont recall the season or episode name, but there was an episode in Voyager that involved a rogue planet that was involved in some sort of ancestral hunting ritual.

I think it's this one from Enterprise https://m.imdb.com/title/tt0572231/plotsummary?ref_=m_tt_ov_...
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