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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

#171

Post by s1artibartfast »

ethbr0 wrote: post #152
chrisco255 wrote: post #147

Earlier quoted context omitted.

Why is it weird that a private corporation is doing space exploration & technology? Most of the biggest sailing expeditions were undertaken by private individuals and companies (although often under the funding of a royal family). Locomotives and airplanes were also created and perfected by private individuals / companies. The 1950s-2000s NASA model for space exploration was unusual in its centralized approach.

There's an argument to be made that some of the current largest market cap companies in the world are analogous to royal families, in terms of centralization of capital vs freedom of decision making.

The notable difference is that they don't have a monopoly on violence

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

#172

Post by ako »

oceanplexian wrote: post #128
semi-extrinsic wrote: post #60

Earlier quoted context omitted.

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…

> 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). Mars might not be sustainable in our lifetime but in a century or two? I think it's within the realm of possibility. As for the urgency, the last two years has demonstrated the exact opposite to me. Modern civilization is a hop, skip, and a jump away from instability and disa…

Even if we completely screw up liveability on earth, it's probably still going to be way more hospitable then most planets we can reach.

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

#173

Post by ethbr0 »

spywaregorilla wrote: post #167
ethbr0 wrote: post #149

Earlier quoted context omitted.

Going to {the Middle East, Europe / Asia, Australia, the New World, interior South America, the North American West) 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 {insert technology} will make a base much easier. There is plenty of work to be done on {current place}. We have to…

Mars is multiple orders of magnitude more difficult to survive on than the Middle East. Its not really comparable at all.

I like to think we've improved our technology a few orders of magnitude in the last 1.8 million years.

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

#174

Post by netcraft »

galacticaactual wrote: post #159
dmarchuk wrote: post #137

Earlier quoted context omitted.

Isn't Parker Solar Probe much faster than that? It's supposed to be going hundreds of thousands of km/h. [1] [1] https://en.wikipedia.org/wiki/Parker_Solar_Probe

It achieved those speeds by falling into a gravity well. Reaching Alpha Centauri requires escaping one.

I very well may be wrong about this, but I believe thats not exactly true. Parker required the fasted launch as of its time because it had to shed the momentum of the earth that it started with to be able to fall into that gravity well.

quoting from reddit:

> You may be thinking of the Sun as a big gravity well and how you can just drop things in a well. But orbits don't work anything like that at all. Sure if you are stationary relative to the Sun then you'll fall right into it. But anything that leaves Earth is very far from stationary. You're going at 30 km/s 90 degrees off your target. Possibly the first idea many people think of if they want to hit the Sun is to cancel that 30 km/s of speed, and sure it'll work. But you need 30 km/s of delta-v. On the other hand, to escape the solar system from Earth you only need a velocity of 42 km/s relative to the Sun, of which you already have 30 km/s. So you only need to increase your speed by about 12 km/s. (And for both cases add one or two km/s to counter Earth's gravity.)

https://www.reddit.com/r/askscience/comments/wjv87/comment/c...

https://www.forbes.com/sites/startswithabang/2019/09/20/this...

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

#175

Post by messe »

thereddaikon wrote: post #82
messe wrote: post #59

Earlier quoted context omitted.

> If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g. Or 9 years if we 'only' get to 0.5c. No, we couldn't. The energy density of fusion isn't anywhere near cl…

Another atomic rockets enjoyer. I've killed so much time on that site. I don't agree with every one of Winchell's conclusions. But they are small things. And I don't know of a more comprehensive and grounded take on future spaceflight technologies.

I was saddened to hear about Winchell's cancer diagnosis last year[1]. I've wasted a ton of time there too, it's an oddity compared to the rest of the modern internet. I know very few other useful sites like it, and I love it all the more for its strange aesthetic.

I don't agree with everything there either, but usually it's only very minor gripes. In this case though, it's hard to argue with the reality of the rocket equation.

[1]: https://twitter.com/nyrath/status/1436010987086286853?s=20

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

#176

Post by monkeywork »

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…

Do you have any suggested reading about:

"A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology."

I was always under the impression that these vast distances were basically entire unreachable in several human lifetimes.

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

#177

Post by s1artibartfast »

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…

>And obviously it would be vastly better for humanity if Musk spent money on zero-emission large scale energy production, than on rockets.

Classic zero sum thinking. Spacex doesn't cost money, it makes it. How much money do you think Musk put into it? The answer is ~100 million seed. It is now worth 35,000 million.

How far do you think that 100m would go to develop fusion. The ITER project alone costs 65,000 million.

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

#178

Post by JumpCrisscross »

samatman wrote: post #94
BeefWellington wrote: post #89

Earlier quoted context omitted.

There's also the consideration of the host star to take into account. I dislike the term "Earth-like" in these publications because it conjures images of a strange alien world able to support (human) life. Even assuming there were life capable of withstanding the constant flares from the host star, I suspect it would have to look very different in color and likely composition to the plant life here due to needing to…

My education was in chemistry, I've wondered about this topic before. Visible light is actually special after removing the happenstance of DNA-based visual systems from the picture: IR tends to twist or translate bonds (warming) and UV tends to ionize. Visible light being right in the middle is the trick which gives us photosynthesis, and sight, because in both cases a photon can be captured by a photosensitive bond.…

> IR tends to twist or translate bonds (warming)

Is this unique to IR?

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

#179

Post by spywaregorilla »

ethbr0 wrote: post #173
spywaregorilla wrote: post #167

Earlier quoted context omitted.

Mars is multiple orders of magnitude more difficult to survive on than the Middle East. Its not really comparable at all.

I like to think we've improved our technology a few orders of magnitude in the last 1.8 million years.

And so you think you can just mush those two claims together and come to the conclusion that sustaining life on mars must be achievable?

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

#180

Post by TheOtherHobbes »

ethbr0 wrote: post #149
spaetzleesser wrote: post #64

Earlier quoted context omitted.

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…

Going to {the Middle East, Europe / Asia, Australia, the New World, interior South America, the North American West) 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 {insert technology} will make a base much easier. There is plenty of work to be done on {current place}. We have to…

This is absolutely, objectively, incorrect.

You might as well argue that you can build a self-sustaining base on Antarctica.

Of course you can't, because Antarctica can't support life. No amount of shouting into a bullhorn about adventure will change that.

It might be possible with an absolutely epic effort to airlift soil, nuclear reactors, nuclear and other fuels, machinery for every eventually (including chip fabs), raw materials that aren't locally available (which means almost all of them), and habitable structures.

At the end of that epic effort you'll have something that will barely have a toe-hold on long-term survivability. Possibly. If you're lucky.

Not only is Mars far colder, it also doesn't have air. Or surface water. So all the challenges are at least an order of magnitude harder.

And it's much much further away.

Rhetoric and wishful thinking are not going to give you a better life if you can't deal with the reality of the challenges.

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