Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Two potentially life-friendly planets found orbiting a nearby star

nationalgeographic.com

Post reply on HN
Print view View original

301–310 of 391 posts

Re: Two potentially life-friendly planets found orbiting a nearby star

#301

Post by Teever »

bdamm wrote: post #213
joshlegs wrote: post #200

Earlier quoted context omitted.

there is an effort to put super mini spaceships on missions to other solar systems, and they would travel at something like 20% the speed of light. I think it works by having the probes be like the size of a cellphone or something, and being attached to a solar sail, then using an incredibly high powered laser to pump the solar sail full of energy to get it going so fast. I think if that architecture works they could…

However, a transmitter with enough power to signal earth would be too massive to get fast with a solar sail, given today's technology. Maybe a chipsat gets to 20% c, but no way a dish does.

What if the chipsat sends the signal to the chipsat behind it which sends the signal to the chipsat behind it which....

So that the signal can be relayed by a bunch of short range transmitters all the way back to earth

Re: Two potentially life-friendly planets found orbiting a nearby star

#302

Post by api »

ascar wrote: post #92
api wrote: post #32

Earlier quoted context omitted.

Look into Project Orion. With thermonuclear bombs you could hit 8% c, which would get you there in "only" 150-200 years including acceleration and deceleration time. That is still beyond humans with present day life spans, but extend life span to ~1000 years or go full AI and you can totally ride the "devil's pogo stick" to stars Fusion rockets would probably be better. I mention Orion because we sort of know how to…

Do we actually have navigation technology to travel at 8% c without crashing into deadly space debris? Or more general: Space travel isn't just about speed.

Space is called space for a reason. Even in real life asteroid rich orbits the odds of hitting something are very low. Pulp sci-fi asteroid fields like the ones depicted in Star Wars are just not a thing. Outside the inner solar system the odds of hitting anything are so low the risk doesn't really rank in comparison with things like major equipment failure in transit.

Re: Two potentially life-friendly planets found orbiting a nearby star

#303

Post by rossdavidh »

m3kw9 wrote: post #279

For those that wants to live on another planet, you will unlikely like how things look under another suns sunlight. It is hard to have a planet that will have day light like our sun and be habitable. Think of a yellow-reddish, or a light that is cold blue when you walk out. Human eyes evolved with earths lighting conditions.

You assume that any of us ever go outside to see the light on Earth, anyway.

Re: Two potentially life-friendly planets found orbiting a nearby star

#304

Post by kevin_thibedeau »

blotter_paper wrote: post #292
jl6 wrote: post #266

Earlier quoted context omitted.

Harder, I think. We have the technology to live on Mars (not to terraform it, just to survive on it). We have some ideas from physics about how to get to a planet 12 ly away, but not the technology. Nor, I would argue, do we have the social and political setup required for such a project, which would most likely take hundreds of years to get to a basic colony.

> We have the technology to live on Mars (not to terraform it, just to survive on it). I'm not convinced this is true intergenerationally without a maternity ward in a centrifuge; the low gravity mouse embryo experiments don't look promising. Maybe 1/3rd earth gravity is enough, but I'm doubtful. If we're granting centrifugal habitats as something doable with current technology, an Orion/Daedalus style nuke-propelled…

We should be colonizing the moon first, then Phobos or Deimos. Then, once established, we can conquer the martian gravity well with local resources.

Re: Two potentially life-friendly planets found orbiting a nearby star

#306

Post by rdm_blackhole »

caymanjim wrote: post #190
XorNot wrote: post #107

The note that it's an old star makes me worry though. If they're older then us, and habitable, were they inhabited? Our current era is a few hundred years of real, directed technological development. A few thousands years either side of that and who knows what we'd be looking at, but you imagine that - hopefully - the general progression of technology is forward. So if they were inhabited, what happened to them? Are…

> So if they were inhabited, what happened to them? Are they exactly at our level of development? Earlier? Hopefully. Because later poses some real big questions - does technology top out about where we are now - no FTL travel, no really big radio transmitters or stellar engineering? No probes to nearby star systems? Did they even make it past the nuclear age, or avoid wrecking their climate? You get more than one ch…

> While finding intelligent life would be great, finding any life is nearly as great.

That would actually be worrisome. If we found and detected microorganisms on nearby planet e.g 12 light years away from earth, then that means we are probably headed for extinction.

The reason is the theory of the Great Filter. Given that we have not been able to observe any kind of activity outside of our solar system, it means that either life is rarer than we think or that entire civilisations go extinct pretty quickly.

If we find microorganism on a nearby planet, the logical conclusion is that life is not as rare as we think but evolved civilisation such as ours simply go extinct in a relatively short amount of time.

The Great Filter may be ahead of us.

Re: Two potentially life-friendly planets found orbiting a nearby star

#307

Post by blotter_paper »

kevin_thibedeau wrote: post #304
blotter_paper wrote: post #292

Earlier quoted context omitted.

> We have the technology to live on Mars (not to terraform it, just to survive on it). I'm not convinced this is true intergenerationally without a maternity ward in a centrifuge; the low gravity mouse embryo experiments don't look promising. Maybe 1/3rd earth gravity is enough, but I'm doubtful. If we're granting centrifugal habitats as something doable with current technology, an Orion/Daedalus style nuke-propelled…

We should be colonizing the moon first, then Phobos or Deimos. Then, once established, we can conquer the martian gravity well with local resources.

I like Musk's plan of using Mars as a fuel-planet, I just don't expect a self-sufficient colony for some time. Mars is like an oil rig or a mineshaft; no place for children.

Re: Two potentially life-friendly planets found orbiting a nearby star

#308

Post by monomyth »

jl6 wrote: post #266
MRD85 wrote: post #263

Earlier quoted context omitted.

Imagine an easy mode planet in a system with multiple habitable planets. Now that I've typed that I'm also considering how Mars would look from 12 light years away. Is establishing a colony 12 light years away easier than transforming mars into a habitable planet?

Harder, I think. We have the technology to live on Mars (not to terraform it, just to survive on it). We have some ideas from physics about how to get to a planet 12 ly away, but not the technology. Nor, I would argue, do we have the social and political setup required for such a project, which would most likely take hundreds of years to get to a basic colony.

> Harder, I think. We have the technology to live on Mars (not to terraform it, just to survive on it).

There is a chance that nuking the polar caps would terraform Mars, I think we already have the technology for basic terraforming.

edit: wrong quote :/

Re: Two potentially life-friendly planets found orbiting a nearby star

#309

Post by samplatt »

erikpukinskis wrote: post #241
soulofmischief wrote: post #165

Earlier quoted context omitted.

Wouldn't each system's star do a decent job of pushing back extra-solar radiation? Up to a point, obviously, but it would seem that planetary background radiation levels aren't a direct function of solar density.

Nope! Some stars are in a stable orbit in a region with some NASTY orbiting interlopers who are eating star systems every million years and have just not made their way to them yet. We have made it at least a billion or so without getting too close to a nasty body so that says something about the region around us.

I'm guessing you've read Incandescence by Greg Egan?

It explores the possibility that general relativity could be discovered by a pre-industrial civilisation living inside an asteroid in a very tight orbit of one those nasty interlopers.

Re: Two potentially life-friendly planets found orbiting a nearby star

#310

Post by inevitable2 »

So much crap... "defacto" science is now dead! Yes please, keep this hyper junk speculations running wild and wide, so these "space" programs can suck as much money as they can, and funnel the money into 3 letter word pus organizations in order to transform the world we live in in a prison. The American people are so gullible.
Post reply on HN