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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

#241

Post by golem14 »

hparadiz wrote: post #106
neom wrote: post #96

Earlier quoted context omitted.

Great in depth youtube video on this project: https://www.youtube.com/watch?v=go-50Dpzs20

This requires sending something to at least about 548 AU and then effect falls off from there but anything you send that far will be going at a velocity that would keep it going. You would be in effective range for some time but basically you'd need to keep sending satellites to that distance in order to keep using the technique. You'd also want to send them into different directions in order to image different parts…

Thanks for that comment, it made me think.

Couldn't you do something like a Hohmann transfer orbit ? As I understand it, adjusting the orbits far out there isn't as demanding as one might think (you don't have to spend the same energy you took to get out there to get into an orbit. Of course, this also means you will not be able to stay in one place and continuously map the same area, but you can map all the space within a disc?

It takes decades however to finish Hohmann transfers that far out apparently.

Rabbithole: Some calculations that may be entirely wrong would suggest that a <10000lbs spacecraft might be held "in place" for 100 yrs with a small fission reactor and an indium-based FEEP drive with about 15lbs propellant.

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

#242

Post by kazinator »

mr_toad wrote: post #231
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 host star is described as very inactive, which probably accounts for the retention of atmosphere.

A really powerful magnetic field could help, also.

Without our field, we would be in trouble, too.

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

#243

Post by kazinator »

Something1234 wrote: post #92
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...

What would a 25km resolution of earth look like

Donald Trump's ego would show up as just one pixel.

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

#244

Post by kazinator »

escapecharacter wrote: post #120
mikepurvis wrote: post #107

Earlier quoted context omitted.

Earth is 12700 km in diameter, so such an image would be 688 pixels across. Basically you won't be reading license plates but you'd see enough to identify evidence of very large scale construction, and with multiple images over time I bet you could draw even more conclusions.

We could make a license plate big enough that aliens could see it and know we are sophisticated.

If four out of seven digits were blurred out, then they would really see how sophisticated we are: we have the concept of privacy!

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

#246

Post by DavidPiper »

throw4847285 wrote: post #225
whimsicalism wrote: post #205

Earlier quoted context omitted.

skimming your comment history, to me you seem very comfortable occupying the sociocultural critic position which is to some degree inherently cynical imo. i say that because i also recognize it in myself

Yeah, but I'm only cynical in relation to what I see as the orthodoxies of the kind of people who post on HN. When I say it like that, it sounds pathetic. And in fact, it is. Yet, here we are.

FWIW I don't think it's pathetic at all, and I have the same reaction as you to a lot of things on HN. There are a wide variety of topics that bring out various biases and other cognitive blind spots in people, and bots.

Space travel seems to be one of the more harmless ones, but I agree it's frustrating to see people implicitly or explicitly skip over things like near-light-speed travel as solved problem, then reject arguments from others as "not thinking big enough", etc.

In general, divorce from reality doesn't seem to be related to intelligence at all in my experience. I'm sure there are plenty of times when my wishful thinking gets in the way too.

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

#247

Post by ufmace »

throw4847285 wrote: post #167

I'm always so alienated (sorry) by the excitement around things like this. People start fantasizing about FTL and space arks and there is just no evidence that any of that is possible, desirable, effective, anything really. I know I'm a killjoy, but I do think there's something negative about the impact of science fiction on engineers. Like, the people who tend (no offense) to be the most literal, black and white thi…

Well I'll give you that most of the stuff about accessing other star systems is deeply unrealistic now. But pretty much all of the awesome stuff that we've actually created in the last 150+ years started out with someone's imagination running away on something that didn't seem very realistic at the time. The idea of having artificial satellites was once a pipe dream, and now we have so many of them we have to redo our numbering scheme to track them all properly.

I'm not gonna hold my breath for the other star system stuff, but if they manage to get the kinks worked out of Starship and it delivers full reusability as promised, it seems like off-world colonies might actually be possible in our lifetimes. If that gets up and running, we might plausibly develop enough space infrastructure that some of the ideas don't seem too crazy anymore.

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

#248

Post by deadbabe »

singingtoday wrote: post #189
Something1234 wrote: post #92

Earlier quoted context omitted.

What would a 25km resolution of earth look like

That's phenomenal. This would bring us so much fascinating information.

No matter how fascinating, some will be underwhelmed by images of cities on exoplanets.

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

#249

Post by deadbabe »

dantillberg wrote: post #117
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.

An even more ridiculous dream of mine: I hope that aliens build a similarly amazing telescope, point it at Earth, and share the images with us, so that we can _see_ our Earth in the distant past.

I hope they picked up dinosaurs and bred them. And maybe bring them back home! Even though our atmosphere is no longer oxygen dense enough.

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

#250

Post by rurban »

dTal wrote: post #87
mekdoonggi wrote: post #33

Earlier quoted context omitted.

According to AI, an equivalent would be roughly when Google maps shows you 10mi/20km reference scale. Turning off the labels, aliens would probably assume that the world is naturally full of green stuff that is dealing with some strange grey infestation.

Even on that scale, major roads and agricultural grids are clearly visible. The mark of abstract intelligence is unmistakeable.

Well, they would see the I-35 out of Houston, but that would show them no sign of intelligence. Just signs of corruption
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