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

bbc.com

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

#271

Post by globular-toast »

chrsw wrote: post #168
creesch wrote: post #144

Earlier quoted context omitted.

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…

Science fiction has entertained and inspired millions of people and we should all be grateful for that but it has also distorted what people think space really is. When you consider the scale of space it becomes pretty understandable why the Milky Way isn't teeming with civilizations sending large amounts of mass all over the galaxy. A realization one comes to despite the facts that it has taken humans a blink of an…

Project Hail Mary does a pretty good job, although probably doesn't come across in the film. SF that doesn't even bother using wormholes or some other FTL travel (e.g. warp speed) is quite annoying, though.

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

#272

Post by leobuskin »

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…

If I understand correctly, time spent within this interstellar ship reference frame would be significantly less than 75k years. And at 1c speed, 48 years on Earth would be ~2 years of "flight" for the passengers, correct me if I'm wrong.

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

#275

Post by ErigmolCt »

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…

I went through almost exactly the same thought process reading this :)

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

#276

Post by ErigmolCt »

mekdoonggi wrote: post #19

We should build a solar lens telescope. By the time we're ready to use it, we'll have a bunch of candidates to point it at.

Yeps. The target-selection problem will likely solve itself long before the engineering does

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

#277

Post by ErigmolCt »

echelon wrote: post #64
PxldLtd wrote: post #40

Earlier quoted context omitted.

There's a project that's going well from NASA for this. Still a moonshot but they've progressed through the early stages well so far. https://www.nasa.gov/general/direct-multipixel-imaging-and-s...

I wonder about all the extraterrestrial AI swarms that have already imaged earth. Surely it has happened. They must have all spotted our planet millions of years ago and must be watching us with a continuous high-resolution feed. They've seen our dinosaurs. Their interest will really be piqued when they finally see us invent electricity, though that might be some time in the future for them. Perhaps even gravitationa…

I do not really believe the wormholes or computronium scenario, but letting my mind run through those possibilities resets my sense of scale

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

#278

Post by ErigmolCt »

naveen99 wrote: post #235

Habitable for silicon intelligence may be more common than habitable for carbon intelligence.

A machine civilization could probably spread into many environments that biology cannot tolerate, but it still has to be invented somewhere first

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

#279

Post by zelphirkalt »

throwawayben wrote: post #220
mr_mitm wrote: post #202

Earlier quoted context omitted.

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.

send an unending chain of them and you solve the transmission problem _and_ they don't have to slow down as you'll always have another on the way past whatever you're targeting

How many times the Earth's materials would we consume doing that? And wouldn't it block ma lazor from reaching the previous probes and accelerating them?

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

#280

Post by creesch »

leobuskin wrote: post #272
creesch wrote: post #144

Earlier quoted context omitted.

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…

If I understand correctly, time spent within this interstellar ship reference frame would be significantly less than 75k years. And at 1c speed, 48 years on Earth would be ~2 years of "flight" for the passengers, correct me if I'm wrong.

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 of light. Project Orion would in theory be able to do 3% to 10% of the speed of light. That's about the only proposed propulsion we actually have the technology for in the sense that we might be able to build it this decade.

So let's be optimistic and assume we can reach 10% of c (unlikely), that is 10 years for one light year, meaning that it takes about five centuries. Practically speaking 10% of c is unlikely, it takes about a month to accelerate to those speeds you'd need an insane amount of mass in the form of bombs to explode to just get up to speed. Which is why 3% is more "realistic". Oh, did I mention that there is no realistic way to slow down either? In theory it is just detonating the same amount of bombs in front of the craft, but in order to take that mass on your journey you'd need a lot more mass to get up to speed and the numbers get silly rather quickly.

So "realistically" at 3% of c we are talking about roughly 1500 years to just speed past our target.

Also, the original remark was about sending probes, not humans. But at 3% or 10% of c time dilation isn't much of a factor either so you'd need a generational craft if you want to send people.

Again, space is big, really big.

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