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First atmosphere found on Earth-like planet in habitable zone of distant star

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Re: First atmosphere found on Earth-like planet in habitable zone of distant star

#291

Post by creesch »

eaenki wrote: post #290
creesch wrote: post #280

Earlier quoted context omitted.

You are not wrong, but it still wouldn't make a whole lot of difference. First of all with any technology we currently have, including hypothetical proposals, we can't even get close to 1c. The best we can do, and this assumes purely hypothetical unproven ideas, is accelerate to a fraction of the speed of light. Acceleration itself will take up a significant amount of time and even then we are nowhere near the speed…

Man, that’s not how intelligence works. Eventually if a civilization doesn’t blow itself up, it will achieve anything, and it’s not incremental steps. Speed has never been incremental steps. in 1810 you would’ve been thinking about faster horses or some shit like that. Def not rockets. OP said hundreds of years. In hundreds of years from now our rulers will definitely have that kind of tech, whatever tech it is.

> Def not rockets. OP said hundreds of years.

Yeah to reach it with current tech. No shifting goal posts, thank you very much.

> In hundreds of years from now our rulers will definitely have that kind of tech, whatever tech it is.

Also, I should point out that technological progress isn't linear and guaranteed. Also, "our rulers" what ...?

Re: First atmosphere found on Earth-like planet in habitable zone of distant star

#293

Post by rustyhancock »

tonmoy wrote: post #260
jjk166 wrote: post #258

Earlier quoted context omitted.

This is false. Earth's magnetic field does not significantly impact atmospheric loss. For comparison, Venus is closer to the sun and has no magnetic field, but has a substantially thicker atmosphere than earth.

I’m not 100% sure I follow what you mean, but here is a link from NASA saying our magnetosphere protects the atmosphere from erosion https://science.nasa.gov/science-research/earth-science/eart...

He's right the magnetosphere doesn't significantly protect our atmosphere. It probably reduces helium loss on earth and other lighter elements.

In addition to his Venus example, Mars lost its atmosphere because it's gravity was too small. Not because it lacks a magnetic field.

Re: First atmosphere found on Earth-like planet in habitable zone of distant star

#297

Post by kakacik »

QuercusMax wrote: post #143
jzu48 wrote: post #134

Earlier quoted context omitted.

As Lynn Margulis reminded us we are not the main show. Our individual intelligence is highly over rated. The brain itself is kludge upon kludge accumulating over thousands of years, to solve problems that keep changing with time and environmental changes. Its quite a piece of crap actually if you tabulate all the accumulated junk. We arent as interesting as we think we are. Some of the tech and knowledge generated mi…

I'd be impressed if those microbes or butterflies visited the moon and came back to tell about it.

Maybe visiting moon is overrated. We can't know, we have very narrow tube vision centered around our rather primitive lives.

Effectively immortal organisms may be more impressive. Or those surviving in anaerobis boiling water conditions. Or fixing radiation defects like its nothing. Or vacuum. Or...

Re: First atmosphere found on Earth-like planet in habitable zone of distant star

#298

Post by gcanyon »

tulio_ribeiro wrote: post #170

Didn't know a rocky planet in the habitable zone of a red dwarf could retain atmosphere against intense stellar stripping. Red dwarfs are known to be cooler (the habitable zone is therefore closer) and unstable. I don't think LHS 1140b is "Earth-like" at all. Rather, it's more like a mini-Neptune, being boiled off by its star. Edit: JWST emission spectroscopy of LHS 1140b as it passes behind its star rules out a mini…

The definition of "earth-like" in this context is almost absurdly broad: roughly it means: a rocky-metallic planet, around Earth mass (maybe 0.5 to 1.5 or so?), and in an orbit that might support liquid water -- not has water, just water would be liquid under some circumstances if it were there.

So:

   - no atmosphere? no problem
   - no water? no problem
   - average temperature 40c? fine
   - 4c? Yup
I think both Venus and Mars qualify (barely).

All to say, when someone says a planet is "Earth-like" that doesn't mean we should get out our picnic baskets.

Re: First atmosphere found on Earth-like planet in habitable zone of distant star

#299

Post by tgv »

creesch wrote: post #144
jimbokun wrote: post #2

48 light years is in our back yard. Close enough that we could probably develop a probe to get there in the next few centuries and check it out. What are the current popular candidates for propulsion systems capable of accelerating to near the speed of light?

Just going to recycle this comment I made in reply to an almost identical comment as yours. I don't think you folks realize how big space actually is. The speed of light is 1079 252 848 km/h, the fastest space craft ever made was the Parker Solar probe (using a sling shot) clocking in at 692 000 km/h. So at that speed it would take, 1559 years to travel one light year. This planet sits at a distance of 48 light years…

I think we can't even build a radio transmitter that covers 48 light years.

Re: First atmosphere found on Earth-like planet in habitable zone of distant star

#300

Post by perilunar »

mr_mitm wrote: post #202
teaearlgraycold wrote: post #184

Earlier quoted context omitted.

If we’re talking about human technology available in a few hundred years, don’t discount far more exotic options. I’ve heard people talk of theoretical terrestrial lasers pushing on tiny probes. With an absolutely gigantic laser and magical material at the back of the probe that won’t instantly vaporize there’s enough energy to get something the size of a smartphone up to a reasonable proportion of the speed of light…

Note that you can't use these lasers to slow down the probe, which will dramatically limit the things the probe can do at the destination. I'm not even sure what kind of interesting things a probe the size of a smartphone could do, let alone phone home.

> you can't use these lasers to slow down the probe

You can, but you need a couple of solar sails. You beam the laser at the sails to accelerate, then at the halfway point one of the sails detaches and becomes a reflector, which lights up the now flipped probe and remaining sail to decelerate them.

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