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Two potentially life-friendly planets found orbiting a nearby star

nationalgeographic.com

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

#51

Post by option »

acidburnNSA wrote: post #46
lmm wrote: post #30

Earlier quoted context omitted.

> I know it's nearby on galactic scales but it's practically about 450,000 Earth years away with current technology :-) If we had the political will, the Orion design could get people there in, what, 200 years, and that's with '70s technology.

Are you talking about the propulsion system where a series of nuclear explosions push the vessel along? https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...

yes, we should explore (and eventually exploit) all forms of propulsion and decide between them based on physics, not politics

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

#52

Post by dekhn »

petercooper wrote: post #31
TeMPOraL wrote: post #23

Earlier quoted context omitted.

And "just" 24 years over radio if there's anyone there to talk with ;).

I doubt I'm alone in this, but I do find it simultaneously amusing and depressing how mind bogglingly big the universe (or even the galaxy) is. It's clear that discovering entirely new levels of physics will be necessary to stand a chance of going anywhere.

you are not alone

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

#53

Post by gutnor »

lmm wrote: post #30
petercooper wrote: post #20

"just 12 light-years away" I love the "just". I know it's nearby on galactic scales but it's practically about 450,000 Earth years away with current technology :-)

> I know it's nearby on galactic scales but it's practically about 450,000 Earth years away with current technology :-) If we had the political will, the Orion design could get people there in, what, 200 years, and that's with '70s technology.

> If we had the political will

It takes more than that. We need political maturity and stability. There is no way we can send people today on a 200 years journey and be sure they will both make it and be able to create a somewhat stable society on the other side.

Also, that would be a earth level effort, another thing that is seriously irrealistic right now. The very best we can achieve right now is the ISS and that's pathetic even compared to current tech.

The biggest push in recent years has been around privatisation of space exploration. It is going to take decades, probably centuries before a commercial model of space settles down and non-profit utopist project like that would be conceivable.

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

#54

Post by stackola »

bencollier49 wrote: post #42
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…

Is that subjective time for the crew or objective time? Is there much of a difference at 8% c?

Assuming 200 years for people on earth, the traveler would experience 199.4 years

https://www.wolframalpha.com/input/?i=time+dialation+at+0.08...

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

#55

Post by pault »

__MatrixMan__ wrote: post #19
yellowflash wrote: post #14

Earlier quoted context omitted.

I always visualized that the tidal locking to be sort of like meshed gears, such that the one revolution around itself is same as a rotation around the star/planet if its a satellite. But that shouldn't affect the day/night in this case right? Since we are talking about planets not satellites of planets and they are light sources not just reflecting light from the star. Can you please correct where I am wrong?

Tidal locking means that the denser side of the lighter body always faces the heavier body, and the less-dense side of the lighter body already faces away from the heavier one. The moon is tidally locked to the Earth, which is why it has a dark side.

So the Apollo "earthrise" photos are just "earth"?

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

#57

Post by pault »

consp wrote: post #15
wongarsu wrote: post #12

Earlier quoted context omitted.

Atmospheres are useful, but are they a requirement for calling a planet life-friendly? Life on earth first developed in liquid oceans, not in the atmosphere.

Wouldn't an ocean vaporise somewhat automatically to create an atmosphere of there wasn't one already?

Well, there's the possibility of liquid water under icy moons.

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

#58

Post by Evidlo »

petercooper wrote: post #31
TeMPOraL wrote: post #23

Earlier quoted context omitted.

And "just" 24 years over radio if there's anyone there to talk with ;).

I doubt I'm alone in this, but I do find it simultaneously amusing and depressing how mind bogglingly big the universe (or even the galaxy) is. It's clear that discovering entirely new levels of physics will be necessary to stand a chance of going anywhere.

Count your blessings. The vast separation between stars means that star systems can have stable planetary orbits for billions of years, which is important for life to develop.

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

#60

Post by riffraff »

petercooper wrote: post #31
TeMPOraL wrote: post #23

Earlier quoted context omitted.

And "just" 24 years over radio if there's anyone there to talk with ;).

I doubt I'm alone in this, but I do find it simultaneously amusing and depressing how mind bogglingly big the universe (or even the galaxy) is. It's clear that discovering entirely new levels of physics will be necessary to stand a chance of going anywhere.

I've read that most of Lovecraft's is derived from the horror at realizing how insanely large in both space and time the universe is.

The unspeakable horrors and mind defying deities in his oeuvre are effectively just reiteration of the "the human race is an irrelevant blip on the universe's radar" concept.

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