Trappist-1b: The Baked Potato Planet.

[Colstan]

Growing up as a child, there's a good chance that an educator or relative told you that we live in an average solar system, orbiting an average star, in an average galaxy. They would have been wrong.

Our Sun is a G-type main sequence star, quite large as galactic travelers go, and hovers around the 90% mark in stellar masses. Our Sun is not small, and only 7% of stars share a similar classification.

Similarly, the Milky Way is not average, either. Along with our galactic neighbor, Andromeda, these two galaxies dominate our neighborhood. While Andromeda is currently estimated to be roughly twice the mass of our home galaxy, most of the surrounding galaxies are dwarfs in comparison. Our other close neighbor, the Triangulum galaxy, is about 10% the mass of the Milky Way.

But what of Earth? What of our own solar system? That's where things get weird. NASA has, thus far, identified approximately 5,000 verified exoplanets around other star systems. We've been searching for an analog to our own system, and have come up short.

Most solar systems have planets that measure consecutively from small to large. Our solar system is a jumbled mess. As an example, imagine if the order of the planets were Mercury, Mars, Earth/Venus, Neptune/Uranus, Saturn, Jupiter. (Sorry, no Pluto, but it's still a real planet to me, damnit!) That's the typical configuration of an average solar system. The first few million years of our system's existence were unusually chaotic and violent.

Then there are gas giants. When astronomers first started spotting planets, they most commonly found what are known as "hot Jupiters", or large gas giants orbiting very close to the host star. With more precise observation, it appears that only about 10% of solar systems host large gas giants. We have two.

Then there are the most common types of planets found around other star systems. One type are what are known as super Earths, which are rocky planets that are generally two-to-three times as massive as our home planet. The other most plentiful exoplanets are called sub-Neptunes, small gas planets which often have a mass half that of Neptune. These two categories combine to make up about 75% of all planets discovered, yet our own solar system hosts neither a super Earth nor a sub-Neptune.

Our solar system, our host star, and our home galaxy are all atypical compared to what we've discovered in the cosmos. This unusual configuration has made it difficult to find a reasonably close twin to our own home planet, Earth.

The challenge in finding a world like Earth is the prevalence of M-type red dwarf stars, which make up about 75% of all stars in the universe. Compared to the Sun, they're small and dim. The habitable zone, where the orbit around the star allows for liquid water, is typically within the orbit of Mercury when compared to our host system. This results in planets that are tidally locked, meaning that they constantly face their host star, much like what happens with our moon. These "eyeball planets" would have dramatically different atmospheres than the Earth.

The second major issue with red dwarfs, is that they are very active during the first billion or so years of their existence, with violent outbursts of ultraviolet radiation bathing any planets within the habitable zone, which may completely strip the atmosphere from those worlds.

Which brings us to the much famed Trappist-1, a star system that has made headlines for years now, because it features seven rocky planets, with at least two of them in the habitable zone. Trappist-1 is only 40 light years away from us, so it makes for a good candidate for observation.

With the aid of the new James Webb space telescope, astronomers are finally able to glimpse the atmosphere of one of these rocky worlds, the innermost planet, Trappist-1b. While not in the habitable zone, the detection of any atmosphere would give a good indication that there is hope for finding Earth-like worlds around red dwarfs. The early results have not been promising.

Webb Telescope confirms nearby rocky planet has no significant atmosphere

A close look at one of TRAPPIST-1's planets shows it's bare and baking.

arstechnica.com

Webb has failed to find an atmosphere around Trappist-1b. These are early results, just a single planet, and definitely not final data. However, if confirmed, it would give an early indication that M-type red dwarfs are likely incapable of hosting habitable planets with a thick atmosphere, and thusly are unlikely to feature a planet similar to Earth, one which could be home to alien life.

While interesting from a scientific perspective, many astronomers believe that we should be searching similar G-type stars to our own, while expanding that search to less massive K-type stars, and hard pass on the red dwarfs. This would be particularly vexing, since our closest stellar neighbor, Proxima Centauri, hosts a rocky planet within the habitable zone.

The search continues, perhaps red dwarf systems will surprise us. However, it's more likely that they host planets that are nothing more than blasted hellscapes, barren planes of nothingness, baked for a billion years in ultraviolet light, rendering it a dark redoubt for eons. Regardless, the search continues for another Earth, but it's not likely orbiting Trappist-1.

 

[Herdfan]

yet our own solar system hosts neither a super Earth

We just haven't found it yet. Evidence exists for Planet X to be a rocky planet 3-10 times the mass of Earth with an orbital period of 10-20,000 years. So it may just be so far out there we can't yet see it, but might as technology improves and it comes closer.

I have always been fascinated by astronomy. And my senior year in college I needed one more science class and a friend talked me into taking astronomy with him. Figured we would learn the planets and other galaxies and other cool things. Nope. It was a 400-500 level physics class and was the only C I ever got. And that was a gift by the professor. He knew I was way over my skis, but since I was trying he cut me some slack.

Looking forward to moving to the desert. We will be in a dark sky community and that combined with clear nights I should be good to go. Already looking at a new GPS based telescope.

 

[Nycturne]

Growing up as a child, there's a good chance that an educator or relative told you that we live in an average solar system, orbiting an average star, in an average galaxy. They would have been wrong.

I wonder how much of this is a mis-application of the copernican principle.

Webb has failed to find an atmosphere around Trappist-1b. These are early results, just a single planet, and definitely not final data. However, if confirmed, it would give an early indication that M-type red dwarfs are likely incapable of hosting habitable planets with a thick atmosphere, and thusly are unlikely to feature a planet similar to Earth, one which could be home to alien life.

Yeah, and I think a big issue we're going to have for a while is that our data is limited. We can't fully survey systems within range yet to find the planets, and as you point out this is the first survey for an atmosphere around a rocky exoplanet. So we really don't have a good grasp of what is out there yet.

The second major issue with red dwarfs, is that they are very active during the first billion or so years of their existence, with violent outbursts of ultraviolet radiation bathing any planets within the habitable zone, which may completely strip the atmosphere from those worlds.

Makes me wonder if these could still be interesting terraforming projects for a civilization with access to enough energy, once easier targets are dealt with. At least once the star is past that early violent era. Less likely to encounter existing life, and there might be plenty of planets where importing an atmosphere and water back into the ecosystem would be a feasible megaproject.

Or perhaps simply dismantling the planet for a Dyson Swarm is a better use of material. Who knows.

 

[Colstan]

We just haven't found it yet. Evidence exists for Planet X to be a rocky planet 3-10 times the mass of Earth with an orbital period of 10-20,000 years. So it may just be so far out there we can't yet see it, but might as technology improves and it comes closer.

I think much of the survey using the TESS telescope data has already been analyzed and nothing has been found, as of yet. Despite doing their best to prevent it, there's always a chance of observation bias, or simply another less flashy explanation. I think it's more likely that there's a unique configuration within our already strange solar system that could be at play in creating those bias orbits among trans-Neptunian objects. Still, the idea of "Planet X" is a lot more fun.

Looking forward to moving to the desert. We will be in a dark sky community and that combined with clear nights I should be good to go. Already looking at a new GPS based telescope.

That sounds awesome. The only three places on Earth with maximal visibility of the night's sky are the open seas, the mountains of Peru, and Amish country in rural Pennsylvania.

Makes me wonder if these could still be interesting terraforming projects for a civilization with access to enough energy, once easier targets are dealt with.

Seeing how M-type red dwarves will shine for a trillion years or more, any advanced civilization may have no choice, after every other option is exhausted. Neutron stars, white dwarves, and black holes aren't exactly the friendliest neighbors.

At least once the star is past that early violent era.

One thing I forgot to mention about our own Sun is that it is a sleepy giant. A study comparing it to other G-type stars found that most of them are significantly more prone to outbursts of highly charged particles compared to our host star, and the K-type stars are even worse. That's been a huge help, both for our atmosphere long-term, and making another Carrington Event less likely in the short-term. Thing is, we don't know if the Sun has always been this quiet, or if it will stay that way.

Or perhaps simply dismantling the planet for a Dyson Swarm is a better use of material. Who knows.

My problem with those sorts of mega projects is the assumption that advanced civilizations actually needs that amount of energy. At some point you're just storing it up like an intergalactic hoarder. I suppose an elder species could be planning for heat death, but that's an inconceivably long time from now.

 

[Nycturne]

That sounds awesome. The only three places on Earth with maximal visibility of the night's sky are the open seas, the mountains of Peru, and Amish country in rural Pennsylvania.

You'd be surprised, Pennsylvania has a good spot, but not quite as nice as upstate NY. Eastern Oregon's high desert is also really good, but the question is for how long. (Light Pollution Map)

But I will always remember being able to see the North American Nebula naked-eye and seeing Jupiter cast shadows during new moon. Can barely see the Milky Way at all anywhere near Seattle or even into the Cascades.

Seeing how M-type red dwarves will shine for a trillion years or more, any advanced civilization may have no choice, after every other option is exhausted. Neutron stars, white dwarves, and black holes aren't exactly the friendliest neighbors.

Although at some point, if life makes it that far, then you're going to need to figure out how to do work with just white dwarves and black holes. Not entirely excited to see that era of the universe.

But yes, a rocky planet that is "just" baked could very well look tempting once you have a civilization with enough energy and few easy targets.

My problem with those sorts of mega projects is the assumption that advanced civilizations actually needs that amount of energy. At some point you're just storing it up like an intergalactic hoarder. I suppose an elder species could be planning for heat death, but that's an inconceivably long time from now.

Energy requirements to move any real amount of mass between star systems in a reasonable timeframe are pretty insane. I would actually be surprised if an interstellar civilization could get away with not having some sort of space-based solar energy collection. A full sphere or ring seems like a waste of resources, but a swarm? I think that style of solar energy collection going to be somewhat inevitable. I don't necessarily think you'd want to just up and dismantle a planet right out of the gate, but I would be surprised if we don't eventually start building out some sort of solar collection system on a scale large enough where strip mining Mercury starts looking like a good idea.

 

[Colstan]

Although at some point, if life makes it that far, then you're going to need to figure out how to do work with just white dwarves and black holes. Not entirely excited to see that era of the universe.

The most fascinating theoretical object to me are iron stars, the last stars, the stars at the end of time. That's when you know it's game over.

Energy requirements to move any real amount of mass between star systems in a reasonable timeframe are pretty insane.

I was thinking of, well, lazy aliens. Once you become advanced enough, at some point there's not much reason for expansion. We're sending out probes, learning about exoplanets, and considering colonizing the galaxy. Eventually, that gets old, repetitive, unnecessary. Maybe advanced species don't colonize galaxies, for various reasons, practical or otherwise. Perhaps such a civilization would turn inward, which could explain the great silence. Of course, many things could, which makes it all fascinating.

I sometimes wonder what would happen if we began exchanging messages with a distant, significantly more advanced civilization, say five million years older than our own. After exchanging pleasantries, we get a series of scientific questions, like do we know what is dark matter, dark energy, quantum gravity, etc. Not necessarily those mysteries, but the simple fact that there are likely properties of the universe that will always be unknowable.

 

[mac_in_tosh]

Our solar system, our host star, and our home galaxy are all atypical compared to what we've discovered in the cosmos. This unusual configuration has made it difficult to find a reasonably close twin to our own home planet, Earth.

Given that there are hundreds of billions of stars in our galaxy and hundreds of billions of galaxies, I'm not sure we are in the position to know what is atypical.

Also, there is some bias in the search for planets like ours. There may be other forms of life based on totally different biology/chemistry.

 

[Nycturne]

The most fascinating theoretical object to me are iron stars, the last stars, the stars at the end of time. That's when you know it's game over.

Honestly, much like I try not to imagine myself in hospice, I try not to imagine the universe in hospice. Too depressing.

I was thinking of, well, lazy aliens. Once you become advanced enough, at some point there's not much reason for expansion. We're sending out probes, learning about exoplanets, and considering colonizing the galaxy. Eventually, that gets old, repetitive, unnecessary. Maybe advanced species don't colonize galaxies, for various reasons, practical or otherwise. Perhaps such a civilization would turn inward, which could explain the great silence. Of course, many things could, which makes it all fascinating.

Who knows. At some point you could get a sort of "large-scale nihilism" as a civilization basically gives up searching for something new or unexpected, or hits a very large hurdle to climb over to reach the next plateau.

I sometimes wonder what would happen if we began exchanging messages with a distant, significantly more advanced civilization, say five million years older than our own. After exchanging pleasantries, we get a series of scientific questions, like do we know what is dark matter, dark energy, quantum gravity, etc. Not necessarily those mysteries, but the simple fact that there are likely properties of the universe that will always be unknowable.

It’s hard to say honestly. Quantum Mechanics is a relatively new field all things considered. Taking a few hundred years to crack some of the harder nuts in cosmology and physics we have today doesn’t feel out of the question. I’m not sure I’d want to bet on unknowable properties just yet.

So much about what we take for granted as knowledge today about physics and cosmology is relatively new knowledge.

 

[Colstan]

Given that there are hundreds of billions of stars in our galaxy and hundreds of billions of galaxies, I'm not sure we are in the position to know what is atypical.

Notice that I never said that Earth was atypical, just the solar system, host galaxy and our big boy star are. I think the data on this is sufficient to make these assumptions, as do most astronomers, from what I gather. Much like polling data, you don't need a gigantic sample size to figure out a general margin. However, I fully admit that there is always room for error, particularly with the cosmos.

Also, there is some bias in the search for planets like ours. There may be other forms of life based on totally different biology/chemistry.

Absolutely, but water, carbon and phosphorous seem particularly well-suited for the development of life. There's a reason that the human body has no use for silicon, which is far more readily available than carbon, despite sharing somewhat similar properties.

As an aside, the "phosphorus problem" is one of the more intriguing potential answers to the Fermi paradox.

Honestly, much like I try not to imagine myself in hospice, I try not to imagine the universe in hospice. Too depressing.

I like to imagine the universe far into the distant future, because it will be vastly different than what we have today. It doesn't make me particularly depressed, because I'll be long dead before it happens.

I’m not sure I’d want to bet on unknowable properties just yet.

Advanced civilizations are still going to be limited by the immutable laws of physics. We often hear of shortcuts like worm holes and negative mass which are little more than fairy tales, things that work on a chalkboard but fall apart in reality. I'm sure there will be many amazing discoveries, but when I hear futurists using magical thinking, my bullshit detector goes off.

So much about what we take for granted as knowledge today about physics and cosmology is relatively new knowledge.

I don't disagree, but I think there will always be unknown unknowns, so to speak.

 

[mac_in_tosh]

I'm sure there will be many amazing discoveries, but when I hear futurists using magical thinking, my bullshit detector goes off.

You mean no subspace communication, transporters, food synthesizers, universal translators and warp drives?

 

[mac_in_tosh]

Absolutely, but water, carbon and phosphorous seem particularly well-suited for the development of life.

That's life as we know it. Throughout history, it was a common mistake to assume we were in some kind of special position, like the whole universe rotated about our world. Yeah, I know it's mathematically valid to describe the world in our frame of reference, but you know what I mean.

 

[Colstan]

You mean no subspace communication, transporters, food synthesizers, universal translators and warp drives?

Just the universal translators. I want to talk to the Andorians.

That's life as we know it. Throughout history, it was a common mistake to assume we were in some kind of special position, like the whole universe rotated about our world. Yeah, I know it's mathematically valid to describe the world in our frame of reference, but you know what I mean.

Oh certainly, I'm just saying that in terms of chemical reactions, those elements appear to be the most amenable towards life. Perhaps there is another way, for sure. I'd love to get a submercible down into the lakes of Titan to see if any little critters evolved while marinating in the methane soup. They'd have much slower metabolic rates than ours, but I don't think it's nearly as impossible as some of the other notions that I've heard.

 

[Yoused]

This is awesome:

Mystery Of Flare A Trillion Times More Powerful Than The Largest Solar Flares Solved

Burn baby planet burn in a disc inferno!

www.iflscience.com

The gas giant planet got just a little too close to its primary, which is now (or was, some 1300 years ago) sucking the gas off the planet to generate a huge, ongoing solar flare.

 

[theorist9]

I'm reminded of this extraordinary quote from Arthur C. Clarke:

Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying.

 

[theorist9]

Growing up as a child, there's a good chance that an educator or relative told you that we live in an average solar system, orbiting an average star, in an average galaxy. They would have been wrong.

One important way in which it's been known that our sun is distinctive is its location. Most of our galaxy's stars are closer to the center. We, by contrast, live in the suburbs, which may be the only reason complex life was able to evolve.

Specfically, according to Astronomy 162: Professor Barbara Ryden, OSU "Near the galactic center, the average distance between neighboring stars would be only 1000 AU (about a light-week)." For comparison, the Oort cloud is located at 2,000 - 100,000 AU.

Stars that close could cause significant gravitational perturbations, making it difficult for planets to maintain long-term stable orbits. In addition, the proximity of so many stars makes planets much more likely to be bombarded (or even sterilized) by neighboring high-energy stellar events, possibly including supernovas and star mergers.

 

[Nycturne]

One important way in which it's been known that our sun is distinctive is its location. Most of our galaxy's stars are closer to the center. We, by contrast, live in the suburbs, which may be the only reason complex life was able to evolve.

Yeah, as I mentioned earlier, the statement Colstan mentioned would be a misapplication of the copernican principle, which states we do not occupy any special position as observers in the universe. But it's a mistake to say that we are around an "average" star in an "average" galaxy. The anthropic principle states we experience observation bias because as observers, we can only be in a location where observers like us can exist. So if the existence of observers like us are rare due to conditions suitable being rare, then so be it.

Specfically, according to Astronomy 162: Professor Barbara Ryden, OSU "Near the galactic center, the average distance between neighboring stars would be only 1000 AU (about a light-week)." For comparison, the Oort cloud is located at 2,000 - 100,000 AU.

Oof, not to mention having stars that close makes diurnal cycles complicated. I kinda wonder what complex life would look like in that environment. What sort of cycles would develop.

 

[theorist9]

Yeah, as I mentioned earlier, the statement Colstan mentioned would be a misapplication of the copernican principle, which states we do not occupy any special position as observers in the universe. But it's a mistake to say that we are around an "average" star in an "average" galaxy. The anthropic principle states we experience observation bias because as observers, we can only be in a location where observers like us can exist. So if the existence of observers like us are rare due to conditions suitable being rare, then so be it.

Yes, exactly. We could be the winners of the universe's biggest lottery, and if we were we wouldn't know it (well, we might eventually, as we expand beyond earth). What seems routine to us, because it happened here (the evolution of life from nonlife, and the evolution of sapience from life), might occur with only a vanishingly small probability. As we yet don't know the mechanism for either, our ability to estimate these probabilities (which are the "f_l" and "f_i" terms of the Drake equation, respectively) remains limited.

And, BTW, your phrase ("observation bias") provides the nicest encapsulation of the anthropic principle I've seen. All others I've encountered are essentially framed as tautologies, which makes them (at least for me) both confusing and meaningless.

Oof, not to mention having stars that close makes diurnal cycles complicated. I kinda wonder what complex life would look like in that environment. What sort of cycles would develop.

Coincidentally, and consistent with my earlier speculation about the deleterious effect of high star density on planetary orbital stability, a couple of recent papers contain estimates that, within the galactic bulge, rogue planets outnumber those orbiting stars by 6x!

I say "consitsent with" because we don't know if gravitational disruption is what ejects planets from their orbits or, alternately, if so many rogue planets exist because many form without having been attached to stars in the first place. But our current theories of planetary formation are that they form around young stars; and, once in orbit, gravitational distruption (as opposed to, say, stellar collapse/collisions/Galactus/the Q) seems the most likely mechanism for so many to be ejected from it.

popular press:

Our Galaxy Is Home to Trillions of Worlds Gone Rogue

Astronomers have found that free-floating planets far outnumber those bound to a host star.

www.nytimes.com

papers:

[2303.08279] Terrestrial and Neptune mass free-floating planet candidates from the MOA-II 9-year Galactic Bulge survey

[2303.08280] Free-Floating planet Mass Function from MOA-II 9-year survey towards the Galactic Bulge

 

[Yoused]

The bulge appears to not be a place to look for LAWKI, as it is populated with a lot of metal-poor stars. Of course, looking things not such as we know is probably more likely to be fruitful, or at least rewarding. We will not be finding Klingons or Pak Protectors or Arrakeen sandworms, so we might as well be looking for things that are not what we expect or would recognze (yes, I admit, looking for something you cannot imagine is pretty darn challenging).