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Earth-like planet spotted orbiting Sun’s closest star

nature.com

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Re: Earth-like planet spotted orbiting Sun’s closest star

#61

Post by politician »

uwuemu wrote: post #33
NeoTar wrote: post #15

Another point for anyone considering whether we should send a space-probe there... The current fastest man-man object is the Helios 2 space-probe, reaching something like 25 000 kilometres per hour. Proxima Centauri is 1.3020 parsecs away from Earth. So, just diving one by the other, we'd looking at something like 18 000 years as a rough order of magnitude for sending something from Earth to Proxima Centauri. You'd b…

A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget. I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think abou…

The only humans who will be utilizing space in earnest are the Martians. Terrans will be confined to their local space with overwatch on the Moon.

Re: Earth-like planet spotted orbiting Sun’s closest star

#62

Post by tjpnz »

rntn wrote: post #13

Sadly, as discussed here, the technical problems with propulsion systems for interstellar travel are non-trivial: https://news.ycombinator.com/item?id=29638529 Of course that doesn't necessarily preclude a nearby higher level Kardashev Civilization becoming interested in all the noise we're making and heading over. As we put up systems beyond Webb, it may be possible to observe a hypothetical inbound craft / fleet so…

If Breakthrough Starshot happens some of us may get to at least see it in our lifetimes.

Re: Earth-like planet spotted orbiting Sun’s closest star

#63

Post by grishka »

rbanffy wrote: post #53
grishka wrote: post #50

Earlier quoted context omitted.

I'm not losing hope that there are ways to travel faster than the speed of light that we haven't yet discovered, like bending the spacetime around the spacecraft, or wormholes, or something else of that kind. If various forms of rapidly ejecting matter out of a nozzle really are the only physically viable option for spaceflight, it would be an extremely disappointing universe.

> If various forms of rapidly ejecting matter out of a nozzle really are the only physically viable option for spaceflight, it would be an extremely disappointing universe. Indeed. If that's the case, the universe is an infinitely big and infinitely boring place. OTOH, our future uploaded selves may be able to slow down their clock rates and make the trip so much shorter. And you don't need to leave your dear ones on…

Frankly, I believe that any form of mind upload or consciousness transfer is a much harder problem than both rejuvenation and interstellar spaceflight.

Looking at current aging research, there's a good possibility we'll see rejuvenation in the next decade or two and it'll profoundly change our society. In 20 years, everyone will be looking 25 years old and pointing at frail people with wrinkly faces and laughing, same way we do today with antivaxxers.

Once that's out of the way, we'll eventually get comfortable with building arbitrarily large objects on orbit, and we could as well build a huge spaceship with an onboard self-sustaining ecosystem and fly that to other stars, the boring way. Yes, it will be a very long journey, but it's possible without the reliance on yet to be discovered new physics.

Re: Earth-like planet spotted orbiting Sun’s closest star

#64

Post by spaetzleesser »

uwuemu wrote: post #33
NeoTar wrote: post #15

Another point for anyone considering whether we should send a space-probe there... The current fastest man-man object is the Helios 2 space-probe, reaching something like 25 000 kilometres per hour. Proxima Centauri is 1.3020 parsecs away from Earth. So, just diving one by the other, we'd looking at something like 18 000 years as a rough order of magnitude for sending something from Earth to Proxima Centauri. You'd b…

A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget. I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think abou…

Going to Mars seems pretty useless to me at this time. It’s a super hostile environment and we don’t have the technology yet to have a self sustaining base there. Give it a few decades and progress in robotics will make a Mars base much easier. There is plenty of work to be done on Earth. We have to solve clean energy production and in general reduce pollution. These are massive technological challenges that deserve massive funding.

Re: Earth-like planet spotted orbiting Sun’s closest star

#65

Post by avsteele »

T-A wrote: post #56

There seems to be some confusion about the meaning of "within the habitable zone". From the paper (Introduction and Conclusions, respectively) [1]: The habitability conditions of Proxima b, which orbits within the HZ of the star, have been extensively studied (e.g. Barnes et al. 2017; Ribas et al. 2016; Turbet et al. 2016; Meadows & Barnes 2018). On the other hand, the candidate Proxima d orbits much closer to the st…

Good catch

"With the small stellar radius, Proxima d ... equilibrium temperature may reach 360K,"

NB: Earth's is 255K. Venus 260K, Mars 215K. So this doesn't tell the whole story, but is probably quite hot.

Re: Earth-like planet spotted orbiting Sun’s closest star

#66

Post by mavhc »

semi-extrinsic wrote: post #60
uwuemu wrote: post #33

Earlier quoted context omitted.

A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget. I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think abou…

Maybe an unpopular opinion, but Musk is just plain wrong when he thinks there is any urgency to Mars exploration (or it's just vicarious arguments because rockets are cool). Basically, the tech you need to make a Mars colony truly self sufficient is something like a compact fusion powerplant. Before we have that, no point in worrying about using Mars as a "backup plan", because if Earth was screwed, Mars would have a…

He should really thing about making a company to do solar, and maybe an Electric Car company that outsells every other USA EV company 10:1

Re: Earth-like planet spotted orbiting Sun’s closest star

#67

Post by politician »

semi-extrinsic wrote: post #60
uwuemu wrote: post #33

Earlier quoted context omitted.

A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget. I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think abou…

Maybe an unpopular opinion, but Musk is just plain wrong when he thinks there is any urgency to Mars exploration (or it's just vicarious arguments because rockets are cool). Basically, the tech you need to make a Mars colony truly self sufficient is something like a compact fusion powerplant. Before we have that, no point in worrying about using Mars as a "backup plan", because if Earth was screwed, Mars would have a…

This is hopeful negativism.

- They don't need fusion. A StarShip can deposit hundreds of solar panels and put them on the ground. No, dust isn't an issue because they'll bring a roomba. No, this isn't a joke, NASA martian probes' solar panels were cleaned by a light Martian breeze.

- They will be able to become self-sufficient rapidly. They're not going to send 1M tons of cargo to Mars without a deployment plan. SpaceX and Tesla have already demonstrated effective vertically integrated supply chains and manufacturing. They have the institutional knowledge to mine raw materials and build factories that build complex parts.

- There are plenty of other Earth-bound governments and billionaires that could devote funds to zero-emission large scale energy production projects. Musk, his companies and assets amount to a very small fraction of the global economy. Your ire is misdirected: your anger about the situation is properly directed at the rule of corrupt imbeciles and their questionable resource allocation decisions (Netflix, coal, etc.) here on Earth rather than one team of folks who seem extraordinarily mission driven and effective.

Re: Earth-like planet spotted orbiting Sun’s closest star

#68

Post by cletus »

Other commenters (rightly) pointed out this is a stretch to the term "habitable".

What's becoming clear though is the only thing stopping us from lots of Earth-mass planets is the abilities of our detectors to detect ever-smaller gravitational wobbles and ever-smaller transits. Bear in mind we only tend to find planets around stars where we're on their ecliptic planes.

So planets seem to be really common. If they weren't the odds of finding planetary systems on our nearest stellar neighbour would be quite low.

But the distances are still so vast that the energy expenditure and timelines are completely impractical (if you assume the speed of light of a hard cosmic limit, which I do).

So if planets are common and interstellar travel is impractical, the only way to expand really is around your own star. This is the Dyson Swarm. This would actually solve the energy issue of interstellar travel (ie"stellar highways") so it's almost a prerequisite. Thing is, Dyson Swarms are likely detectable from vast distances due to their IR emissions (ie the only way to get rid of heat is to radiate it into space and that has a specific frequency depending on the temperature of the radiating object).

But if planets are really common and we don't see any Dyson Swarms it seems that spacefaring life is extremely rare and the most likely number of such civilizations in the Milky Way is 1 including us.

Re: Earth-like planet spotted orbiting Sun’s closest star

#69

Post by dsign »

politician wrote: post #61
uwuemu wrote: post #33

Earlier quoted context omitted.

A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget. I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think abou…

The only humans who will be utilizing space in earnest are the Martians. Terrans will be confined to their local space with overwatch on the Moon.

> ... overwatch on the Moon.

I'm pretty sure not even that.

Re: Earth-like planet spotted orbiting Sun’s closest star

#70

Post by seventytwo »

uwuemu wrote: post #33
NeoTar wrote: post #15

Another point for anyone considering whether we should send a space-probe there... The current fastest man-man object is the Helios 2 space-probe, reaching something like 25 000 kilometres per hour. Proxima Centauri is 1.3020 parsecs away from Earth. So, just diving one by the other, we'd looking at something like 18 000 years as a rough order of magnitude for sending something from Earth to Proxima Centauri. You'd b…

A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget. I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think abou…

The best thing we could do for space exploration is to figure out terrestrial fusion.
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