TRANSCRIPT: The Zoo Hypothesis

The human race has looked out into the night sky for decades with our radio telescopes hoping to find signs of life. And while that search is ongoing, we have yet to see anything. For all intents and purposes, our universe appears quiet and uninhabited by other technologically advanced civilizations.

This could change at any moment, all we need to do is discover evidence of one other sentient species to answer many of our questions about life in the universe, but until that happens we must entertain other possibilities to explain this apparent lack of intelligent life.

One of the possibilities that we face is that intelligent alien races do not advertise themselves, and indeed may hide their existence from us. Known as the zoo hypothesis, it is one of the plethora of hypotheses that offer answers to the Fermi Paradox. It also happens to be among the spookiest.

The Fermi Paradox, formulated by physicists Enrico Fermi and Michael Hart, is very simple. There are billions of stable stars in our universe, and many of them are far older than our own. There is also a high probability that some of these stars host earth-like planets, a notion that has only been strengthened in recent years by the discovery of numerous exoplanets. Likewise, many of those are going to be far older than earth.

Some of those planets would, presumably, develop life like ours that eventually achieves intelligence. Here I have a sticking point, in my opinion I think that ultimately we may well find that microbial life is common in the universe, complex life like our plants and animals scarce, and intelligent life very rare. But I digress. Assuming that civilizations are relatively common then some of those will develop interstellar travel.

Here I have another sticking point. I'm not sure that an advanced civilization would care about interstellar travel. This relates to Simulation Theory, the notion that our universe is a computer simulation of some sort. I cover that theory in my video "Is the Universe real? Or is it a Computer Simulation?" and whether it's actually the case is anyone's guess, though it does appear to be scientifically testable.

But let's say the universe is a computer simulation as a thought experiment. If a civilization concluded that it is a simulation, then they may also conclude that there is no point to messing around with the universe. In such a nihilistic scenario, why not center your society on pleasure and descend into virtual reality utopias that are better than our universe? Think about The Matrix, only as a utopia, though I suppose Agent Smith had a point when he said in the films that they actually did initially try to create a utopia but no one was happy.

But, it's worth noting that we ourselves are striving for interplanetary exploration and eventually interstellar travel. Our behavior is all we can study for now, and that does count for something. Given that habitable planets exist, and they eventually become inhabited and may have done so long before earth did, and those inhabitants eventually spread out into the universe, then the Fermi Paradox notes that the entire galaxy can be explored at sub-light speeds in only a few million years. So why don't we see evidence of alien civilizations everywhere?

This brings us to the Zoo Hypothesis. The idea here is that alien civilizations hide themselves from us, either permanently or will some day reveal themselves and make contact when we've reached a sufficient level of technological and social development.

This may make sense. If the universe is a hostile place full of aggressive species, and your basic nature would be aggressive in some way if you're out boldly exploring the galaxy, then perhaps it's safer to hide and not contact anyone. In this scenario, advanced civilizations simply play it safe and do not interact with one another other than perhaps clandestine interstellar spy missions.

Or a civilization may find value in galactic diversity and not contact anyone so that they may simply study young civilizations and their natural development. This is something we ourselves do, there are still to this day uncontacted stone age tribes on our world and we take care to preserve that both for their own safety and ethical concerns about first contact, which has seldom gone well in the past.

But, you also have to ask a question here. If advanced civilizations are common and hiding their existence from lesser civilizations, then surely at least one of those advanced species would break the trend and show themselves. If they are common, then they must all be hiding and that would imply that somehow everybody out there is in agreement to hide. How does that work?

Now, this is pure speculation, but say a single civilization developed in the Milky Way long before any others. Even a billion years or longer before anyone else is possible. Say they colonized the entire galaxy, but hide their existence until a civilization they're watching matures. As other civilizations mature and meet this ancient civilization, the old ones may impart their wisdom of hiding to all civilizations in the galaxy. As a result, developing civilizations think they are alone, until one day they find out that they are not.

While an interesting idea and I make this video as merely food for thought, I still suspect that intelligence is simply rare, and when it does develop it takes time and a lot of chance. Finding evidence of such a rare civilization is like searching for a needle in a haystack for SETI and that some day, perhaps sooner rather than later, we will wake up to a changed world where we know unequivocally that we are not alone.

Thanks for listening! I am futurist and science fiction author John Michael Godier currently issuing a rebuttal to those that think I'm a robotic voice simulator. Not quite, but close. It's more like The Matrix, Mr. Anderson.

Just kidding, I'm really just a vulcan and be sure to check out my books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live. 

TRANSCRIPT: Water Worlds, Desert Planets and ... Titan

One of the many questions that I wonder about is how rare Earth actually is.  Over the years, the consensus on that question has evolved somewhat from earth not being particularly special in the universe, perhaps even outright pedestrian, to earth looking increasingly special and rare with many factors playing into its habitability and ability to support the evolution of a technological species.

A new paper, link in the description below, authored by Fergus Simpson of the University of Barcelona may help shed some light on this question. This paper details an interesting prediction made by S. F. Dermott and Carl Sagan in 1995. At the time, it was thought that Saturn's moon Titan was likely to harbor hydrocarbons in liquid form. Just how much liquid would be present was open for debate and it ranged from vast oceans to Dermott and Sagan's idea that it wouldn't be anywhere near that extensive.

They predicted that if such oceans were present on Titan, its orbit would have been circularized by the action of tidal forces. That seemingly turned out to be correct, we know now that Titan's surface liquids are confined to a relatively sparse group of lakes. On the other end of the scale, we have Enceladus and Europa where there are strong indicators of deep subsurface liquid oceans, meaning that these two bodies are water worlds coated with a layer of ice with no known land.

The paper details that, statistically speaking, the division between land and ocean on a planet should be asymmetric. This implies that habitable exoplanets are either likely to either be water worlds where the surface is mostly, or entirely, covered in ocean or desert worlds where liquid water is present but scarce. Earth is the odd planet out given that we have a good amount of ocean but also lots of land.

Examples from science fiction of worlds like these would be dry, arid Tatooine from Star Wars or Thalassa from Arthur Clarke's novel "Songs of Distant Earth" which was a water world with a few human-inhabited islands, which may be the more common of the two in the universe.

While this does not preclude life arising on either water worlds or desert worlds, it does affect whether a technological civilization can arise. I've said in past videos that it would be exceedingly difficult for dolphins to master fire and smelt metal, regardless of their level of intelligence. On a water world, there may well be intelligence, but it might be locked in by its physiology perhaps awaiting direct contact with an alien species to liberate them from their world.

Now, much study of exoplanets will be needed to confirm or refute this paper, as Paul Gilster on his blog Centauri Dreams notes, we don't really yet have a complete picture of water delivery in the early solar system and that could affect the abundance of earth-like distributions of water within habitable zones.

Which brings me back to thoughts of strange Titan. It too is thought to have a subsurface very salty liquid water and ammonia ocean making it a sort of hybrid between a dry world and an ocean world. It may even harbor life, potentially several flavors of it in fact, one type on the surface, and another in the ocean. And it has another odd distinction, there will be a period 5 billion years from now where the sun will expand into a red giant. For a time during this period, its thought that Titan will be warm and become habitable and earth-like for a few hundred million years.

Will we some day retreat there to avoid the fury of the reddening sun and Earth's armageddon? Or will we be long gone and someone or something else arises on that little world? I find that future fun to ponder.

Thanks for listening! I am futurist and science fiction author John Michael Godier do check out my patreon page, link in the description below and be sure to check out my books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live.   

TRANSCRIPT: Are We the First Technological Civilization in the Solar System?

Digging through scientific papers as I do to research the content featured on this channel is something very much like hunting for Easter eggs. I would never call any scientific work mundane, any work done by scientists helps to advance our understanding of our world around us, but I might say that most subjects one sees in scientific papers just would not make for good YouTube videos unless done by a creator far better than I.

But several times a week I find papers, or easter eggs if you will, that excite me and then I go make videos on them. Occasionally, however, I will read a paper that absolutely blows my mind. That definitely happened this morning.

This paper is entitled "Prior Indigenous Technological Species" and was authored by Dr. Jason T. Wright of the Department of Astronomy and Astrophysics and Center for Exoplanets and Habitable Worlds at Pennsylvania State University, link to the paper in the description below. It's a good read folks.

But first some back story. It might surprise you, but it is fully scientific to consider the possibility of alien life having visited our solar system in the past. Carl Sagan and I.F. Schklovskii pointed this out in their book "Intelligent Life in the Universe" in 1966. This is independent of the question of whether the human race has ever interacted with an alien race. I have no problems with those that have concluded otherwise, but I have personally seen no compelling evidence that would lead me to conclude that we have. I have only seen material that leads me to more questions.

But the universe is a very old place, certainly old enough for other technological civilizations to have arisen long before ours did. It's also sufficiently old enough for an ancient civilization to have explored the galaxy end to end without exceeding the speed of light. Earth too, is sufficiently old enough to have been explored at some point in the distant past.

And, it's also fully within the realm of solid science to look for evidence of that as part of SETI operations, and indeed I've made several videos on this channel on the possibility of Bracewell or von Neumann probes hidden somewhere in the solar system. The tough question though is how likely is it that such a thing might exist?

This subject was tackled in a 2011 paper by Jacob Haqq-Misra and Ravi Kumar Kopparapu entitled "On the Likelihood of Non-Terrestrial Artifacts in the Solar System", link to the paper in the description below. They concluded that we simply have not explored our solar system thoroughly enough yet to detect such probes, if they exist, and that we should probably keep our eyes open for them just in case.

Dr. Wright in his new paper takes an interesting approach to the question of artifacts of other civilizations present in our solar system. He points out that while astrobiologists focus on searching for present or past evidence of simple life in our solar system, it may well be the case that artifacts of advanced civilizations are easier to find. And, going further, he suggests that the origin of such an artifact does not necessarily need to be another star system, but could be the solar system itself.

It is possible that advanced civilizations may have developed in the past on Earth, or even Mars or Venus which are thought to have once been earth-like. But Earth and Venus are geologically active worlds that renew their surfaces, so any evidence of an ancient civilizations is likely to be long gone on these planets. But you might find evidence of them on less active worlds like Mars or the Moon. Another possibility is that we might find an asteroid that was clearly mined at some point, perhaps by a von Neumann probe passing through.

Dr. Wright points out though that if we do find evidence, which we currently have absolutely none that stands up to scrutiny, then you must consider that the origin might not be another star system, but instead may be more likely to have originated from our own star system, especially considering that Earth would be a sort of elephant in the room since life has clearly arisen here.

While I consider it unlikely that there were ever precursor civilizations in our solar system, it is possible. And it's also possible that some day in the distant future others, perhaps from some formerly frozen moon made habitable by the brightening sun, might find evidence of us.

Thanks for listening! I am futurist and science fiction author John Michael Godier currently with a new book in the works, it's called Supermind and a 5000 word excerpt is up at Amazon Kindle Scout, link in the description below, check it out and if you like it give it a nomination! And be sure to check out my other books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live. 

TRANSCRIPT: Life on Jupiter?

Jupiter, at first glance, is perhaps the last place you would expect to find life. It's after all a roiling, hot gas giant. But it might surprise you that the gas giant itself has, at least in the past, been considered a possible home for life. And not just microbial life, but complex life. And while it's a long shot, it's not ruled out that something could inhabit the upper reaches of its atmosphere.

Jupiter is a generally misunderstood world. It's usually thought of as a huge ball of gas. But in reality, it's much more complicated than that. If you descend into Jupiter's atmosphere, you will first find a turbulent upper layer made up of a mix of gases, mostly hydrogen and helium. The further you go down, the hotter it will get due to the high pressures of the interior. At about 1000 kilometers below the top of the cloud deck you transition to one of the stranger natural substances thought to exist in our solar system. You would find metallic hydrogen.

Under the extremely high pressures of Jupiter's atmosphere hydrogen would be compressed into a soup of nuclei and electrons that exist in an ambiguous state that wouldn't have a clear boundary between a gas and a liquid. While metallic hydrogen is described as a liquid, it's a bit different than any other. It's better to think of the hydrogen as simply getting denser the deeper you go rather than use labels. Beyond that thick layer at the heart of the planet, it's thought you would find a core.

Not a lot is known about this core, but it's probably made of rock and metal just like the inner planets. It's not yet known if it's solid or completely molten or some mix of the two. Planetary cores are generally hard to study, and Jupiter's is among the hardest. But how could such an alien and strange environment such as Jupiter support any kind of life? The answer is in the conditions of the upper atmosphere.

In 1976, Carl Sagan and Edwin Salpeter released a paper, citation in the description below, in which they suggested that ammonia-based life of some kind might exist in the atmosphere of Jupiter. They envisioned three hypothetical kinds of animal that might live there which they termed sinkers, floaters and hunters. In particular, the floaters were envisioned as enormous gas bags, perhaps kilometers across and visible from orbit that suspended themselves in the atmosphere using helium.

Now, we have never seen floaters with any of our probes to Jupiter and this was a very speculative paper based on thinking deriving from what we know about our own oceans and life there. No such indications have ever surfaced that such a thing could really exist on Jupiter. But what does exist at Jupiter is the possibility of some interesting life related chemistry. The chemicals in the upper atmosphere of Jupiter do include water, ammonia and methane along with plenty of hydrogen in gas form.

These just happen to be the gases used in an interesting experiment done in 1952 by Stanley Miller and Harold Urey. They wanted to recreate the conditions of early earth and see if they could produce the initial prebiotic chemical reactions that are believed to have ultimately led to the dawn of life on earth.

What they did was pass water vapor through a mix of hydrogen, ammonia and methane gas. They then subjected that mix to periodic electrical discharges intended to simulate lightning. Then they looked at what came out the other side and it was, to say the least, interesting.

They found lots of organic compounds coming out of the mix. Most importantly, they initially found a number of the amino acids that are used by life. In 2007, however, the original sealed samples from the experiment were reexamined and as it turns out all 20 amino acids were present that are used by life on earth.

Since then, numerous revisions have been made to the model of what our planet's early atmosphere was like. As a result, a number of subsequent experiments have been done based on the Miller-Urey work ranging from changing the energy source to a volcano rather than lightning, adding in new chemical mixes that more accurately resemble what the early atmosphere is thought to have been like and so on. The results of many of these experiments has been the creation of even more types of organic molecules than Miller and Urey's experiment produced.

These experiments make it seem likely that at least the basic the chemistry for life first arose on some volcanic island on Earth billions of years ago. For Jupiter, this would be a more difficult process though it does have extremely powerful lightning and no shortage of heat. The problem is in its atmosphere, which is extremely violent. Gases circulate on that world by rising in certain areas and falling in others and any kind of life, microbial included, would have to deal with impossibly high temperatures and pressures when circulating deep below.

As Sagan noted in a segment on this topic in his television series Cosmos, such organisms would have to reproduce very rapidly. And while the prospect of life living in the atmosphere of Jupiter is somewhat of a stretch due to that roiling atmosphere, there may be gas giants and even brown dwarves in the universe calm enough to harbor at least some form of microbial life in their upper atmosphere, or possibly even more.

In a paper by Jack Yates and his colleagues at the University of Edinburgh from late 2016, link in the description below, they detail a hypothetical way for brown dwarves to harbor some form of life. They note that the upper atmospheres of some brown dwarves might harbor clement conditions with pressures and temperatures similar to earth. Relying on updrafts, life might exist in this zone within the brown dwarves.

This opens up vast new territory in the search for life in the universe. In 2013, a brown dwarf known as WISE 0855-0714 was discovered and seemingly has water-based clouds floating in its upper atmosphere. Using Sagan and Salpeter's research, they applied that thinking to the brown dwarf and concluded that yes, life might exist there.

The James Webb Space Telescope is slated to take an in-depth look at close brown dwarves, such as WISE 0855-0714 which is only 7 light years away. And while it's hard to envision native life having a way to evolve in the first place in a place like Jupiter or a brown dwarf, it's been suggested that dust floating in the atmosphere might do the trick for a solid place to do it or even microbial life being delivered by an asteroid through panspermia.

One can imagine that this kind of inhabited gas planet might be quite rare, but it does seem to at least be hypothetically possible and that in the future, when we do detect evidence of life, perhaps it might come from the spectra of a brown dwarf's atmosphere. But I'm left with one lingering, highly speculative thought after making this video. If Jupiter, then why not Saturn?

Thanks for listening! I am futurist and science fiction author John Michael Godier currently probably sounding a bit scratchy because it's spring and my allergies are working overtime and be sure to check out my books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live. 

TRANSCRIPT: Life on Io?

One of great unknowns of our solar system is whether it hosts other life, particularly microbial. I say the words other life carefully because there are two types of potential life in our solar system for us to consider. The first of these is life that evolved independently of earth life without any influence from here. This would be truly alien life and would give us an indicator that microbial life in the universe at large is probably common.

The other potential for life in the solar system is life transported from earth via panspermia getting deposited somewhere else and gaining a foothold. Our planet is teeming with microbial life, some of it extreme and possibly able to survive the rigors of space. It's entirely possible that we, the human race, will not claim the title of being the first life from earth to colonize other worlds.

This has led me to research just where either of those forms of off-earth life might exist in our solar system. There are obvious candidates such as Mars or Europa, but there were other candidates that surprised me when I went searching for the science on the subject. This video is the first in a series on this channel exploring those places, and this candidate is one that if it does harbor life, it's probably going to be centuries before we know about it.

That's because it would be exceedingly hard to verify its existence. It's Jupiter's moon Io and the reason for why it's going to be a while is that there is just no compelling reason to try to land on this moon. Studies from spacecraft passing by from afar are feasible, but expensive and with life there only just being within the realm of possibility it seems that Io will not be a priority for exobiological study for some time.

First there's just not much on the surface, it's basically just a big ball of mostly sulfur compounds. And a lander might well melt as it's the most volcanically active body in the solar system kept so by intense gravitational flexing it as it orbits. But volcanism is a dual-edged sword. While it can easily kill life, it can also provide an energy source for its genesis and indeed some models for how life arose on earth depend on the presence of volcanoes.

A possible way for life to survive on Io was presented by Dr. Dirk Schulze-Makuch in a 2010 paper in the Journal of Cosmology, link in the description below. The key to the possibility of microbial life on Io is linked to its history. Io is old, having formed about 4.5 billion years ago and today it has the least water out of any object in the solar system.

But that may not have always been so.

Objects in the outer solar system are typically rich in water ice anyway, and the models suggest that Io formed in an area where water ice was particularly plentiful in the Jupiter system. Given geothermal heating, some of that water might have been liquid opening up the possibility for the chemistry of life to get going, at least for a while, this would have had to happen within the first ten million years of that moon's existence. And, as we learn more about the early conditions present in the Jupiter system, it may be the case that it was  always impossible for life to arise on Io. But, at least right now, there is a chance.

Now, life on Io's surface is improbable and not just because of the volcanic activity. Jupiter blasts its surface with very high levels of radiation, and that likely precludes any possibility of panspermia or at least makes the chances low unless it happened very early on and native life could not arise there now. But beneath the surface of Io the conditions might be just  right for microbes originating from Io's early history to hold out.

Jupiter's radiation long ago deprived Io of its surface water, but below the surface there may be carbon dioxide and water in liquid form. And Io could well have several other potential liquid solvents for life including hydrogen sulfide, sulfur dioxide and even sulfuric acid.

Another important factor to consider would be the presence of lava tubes. Lava tubes are rich abodes of life here on earth and may also be so on Io. They provide protection from radiation and can be moist environments and also temperatures within the tubes could be both constant and warm.

But that's not the only way. The paper advances another model where the microbes might exist as dormant spores underground for very long periods only to be activated when lava is flowing on the surface above warming any fluids below to liquid temperatures and allowing a blossoming of life for a time before it once again goes dormant.

So while life on Io is a long shot, and there are far better candidates in our solar system that we must look at first, Io may one day prove to be more interesting than we might have imagined.

Thanks for listening! I am futurist and science fiction author John Michael Godier currently with a new book in the works, it's called Supermind and a 5000 word excerpt is up at Amazon Kindle Scout, link in the description below, check it out and if you like it give it a nomination! And be sure to check out my other books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live.

TRANSCRIPT: LHS 1140b Exoplanet Update for 04/19/2017

Yet another case of a seemingly habitable world orbiting an M type red dwarf has surfaced. Just 40 light-years away, a super earth exoplanet has been found that seems to have, at least on its face, the best chance of detecting earth-like habitability that we have yet seen.

Known as LHS 1140b, this planet has some significant differences with earth. For one, it's about 1.4 times the size our planet and thusly would have higher gravity. It's mass suggests that it's rocky like our inner planets, which favors complex life.

Planets within the habitability zones of red dwarves need to orbit very closely, LHS 1140b for example orbits so close that its year is only 25 days so it would probably be tidally locked to its star, and perhaps make it an eyeball world with a habitable twilight area as some models of Trappist - 1 and its planets suggest. See my videos on that system on this channel.

Yet, even at that distance, LHS 1140b still only receives about half as much light from its star as we do from ours. Still, that's enough to maintain liquid water, at least on parts of the planet. And, unlike stars such as Trappist -1 which are thought to have been extremely active in their youth for a long period of time and might have stripped their worlds of their atmospheres, LHS 1140 is thought to be a relatively stable, quiet star that had an active phase early in its life that lasted only 40 million years. Trappist - 1, by contrast, was more to the tune of a billion years of activity.

With the discovery of first Proxima B and then the Trappist - 1 system, exoplanets within the habitability zones of red dwarf stars is a very active area of study. This is because planets within those zones are easier to see if you're dealing with a red dwarf as opposed to brighter stars like our sun. You could say that there is a sweet spot between stars that are too hot and bright and stars that are too dim to be suitable for studying transiting exoplanet atmospheres.

But it goes deeper. It's not yet clear how habitable red dwarves are. Only observations of exoplanets orbiting them will tell. But they are by far the most common type of star in the galaxy. Calm, stable stars like our sun are much harder to come by and the habitability question of red dwarves will figure prominently in determining how common life in the universe is.

But studying exoplanet atmospheres is a tricky thing. There are actually quite a few more detections of potentially habitable planets in our galaxy that come from the Kepler spacecraft, but their atmospheres aren't easy to study due to them being very distant, at least as far as detecting gases associated with life are concerned.  

But even when exoplanets are close, it's still not easy. In the case of Proxima-B, for example, it was discovered through its gravitational effects on its star. Think of it tugging on the star and astronomers can detect that wobble and infer a surprising amount of information from that, that's how LHS 1140b's density was determined. But what Proxima B doesn't do is pass in front of its star within our line of sight, which makes studies of any atmosphere that may be present exceedingly difficult.

And another problem faces those wishing to study Trappist - 1. Looking for biosignatures in the atmospheres of its worlds is difficult because of the nature of the star itself. While it is a star, it's as small and cool as they get. That means it's dim, and that means it's hard to use it to look at spectra passing through planetary atmospheres to look for things like oxygen which, if found, could suggest that life is present.

This makes LHS 1140b an attractive candidate as a starting point of studying exoplanet atmospheres for signs of life. Since the planet has higher gravity, it can better hold onto an atmosphere. And, when you know the density of a planet, you can determine how tightly it holds onto that atmosphere.

Plus, since the star was only active for 40 million years in its youth before quieting down, that also favors habitability. And since that active period would have happened shortly after the formation of the system, even if the planet did lose its atmosphere it might have been replenished by way of gases and water released by a still molten surface. How much water might be present on such a world and how much ultraviolet light and radiation bathes the planet remains to be seen, though the star seems to spin slowly which bodes well.

So LHS 1140b is the top current candidate for scientist's to look at for biosignatures. And the good news is that they certainly are looking. The team studying the system, lead by Jason Dittmann of the Harvard-Smithsonian Center for Astrophysics, link to their press release in the description below, are actively studying it to pin down the conditions in which this planet exists. Using the Hubble Space Telescope and a whole array of ground-based telescopes later this year, they will try to see an atmosphere and figure out what it's like.

If oxygen is found, in the future, instruments such as the James Webb space telescope and the Giant Magellan telescope will allow scientists to determine if that's due to the presence of life.

Thanks for listening! I am futurist and science fiction author John Michael Godier currently recording the audio track for this video which I will soon do again for my other channel John Michael Godier II which is dedicated to science fiction, link in the description below and be sure to check out my books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live.

TRANSCRIPT: GJ 1132b Update for 04/06/17 Exoplanet Atmospheres

At first glance, this story might not seem to have much of a connection to the question of life in the universe, the planet I'm about to discuss is probably about as hostile and uninhabitable as they get, but in fact it answers a long-standing question about exoplanet atmospheres and just where they can exist. That, in turn, has implications for where life, at least as we know it here on earth, can arise.

GJ 1132b is an exoplanet discovered around a star located about 39 light years away from us. It's a small planet, just a bit larger than Earth and is thought to be rocky. It's been called a potential Venus twin due likely having a very high surface temperature similar to Venus, though it's probably even hotter. It was also thought to likely have some type of thick atmosphere, though the composition was unknown. This atmosphere has now been directly observed.

Scientists have observed the atmospheres of exoplanets before, though up until now it was limited to gas giants and planets much larger than earth. This is the first time they've directly observed a planet with an atmosphere that is roughly in earth's class as far as size, but the similarities end there.

John Southworth of Keele University in the UK and colleagues used the European Southern Observatory or ESO, a hotbed for exoplanet discoveries as of late, to confirm the size of the planet by studying it as it transited in front of its star. But they saw something else within the data. One of the wavelengths of light they were studying seemed to be blocked by an atmosphere of some type, though its composition isn't yet fully understood.

This has an important implication regarding stars that can have habitable planets in the universe. Stars fall into different classes, our own sun being a G type yellow dwarf. GJ 1132b's star is an M-type dwarf, by far the most common kind of star in the Milky Way, in fact Trappist - 1 is in that class. GJ 1132, the parent star of the planet, is a type of star that tends to be pretty active and, up until now, it was unclear if any planets orbiting very near such a star could hold onto their atmospheres. For our kind of life here on earth, obviously having an atmosphere is quite important.

GJ 1132b seemingly answers the question. Yes, planets orbiting close to at least some M type stars can hold onto atmospheres. That potentially opens up a huge amount of stars to the possibility of harboring earth-like planets. But as far as GJ 1132b is concerned, it's not earth-like at all.

But what might GJ 1132b's atmosphere look like? One hypothesis based on the data is that it might be largely made up of water vapor, basically a steam bath world, or a world high in methane. The planet is close to its star, so it would probably be tidally locked, always presenting the same face towards the star. That's about all that can be said though.

But in the future this world is set to be a priority for study, especially with the James Webb Space Telescope. Other than Venus, this is the first roughly earth-sized planet with an atmosphere that we can study. As the facts about the planet come out, it will become a planet that we can envision what it might be like better than most other exoplanets. Scientists should eventually be able to work out the planet's color, what sort of winds it has, and even what sunsets might look like on this world.

Thanks for listening! I am futurist and science fiction author John Michael Godier currently hard at work preparing content for the new channel and be sure to check out my books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live

Trappist - 1 Update for 04/10/17

This video is part of my continuing coverage of the Trappist - 1 system. This star system is known to harbor at least 7 roughly earth-sized planets, and may hold the potential for liquid water on at least one of them. For the back story on this system, see my previous videos on this channel.

Much new information has come to light about this system, so much so that I'm barely able to keep up with the veritable snowstorm of scientific papers that have been coming out. One thing that hasn't changed about this system though are the uncertainties surrounding it, and it will be a while before any sort of consensus can be made on what these worlds are really like.

One of the main uncertainties involved with Trappist - 1 was the role of the outermost seventh planet and how it relates to the inner planets and the orbital stability of the system as a whole. This is because in the initial observations that planet had only been observed to transit once in front of the star.

But, in a paper from March 12, Rodrigo Luger and colleagues report further observations done with the Kepler space telescope that have narrowed down this planet's orbit and suggest that Trappist - 1h, which is thought to be larger than Mars but smaller than earth, could harbor liquid water with the right atmosphere, which would be some mix of hydrogen, nitrogen and carbon dioxide and could thusly be habitable.

But that's a could be, as with most of the planets in this system. A big factor here is stability, and that's a question that's in flux. Planets without stable orbits aren't conducive to life, especially if they occasionally ram into each other. So, while it's not yet known just how stable this system is, it seems to be moving into more stable territory. A paper from this morning by E.V. Quintana and colleagues suggests that the presence and characteristics of the seventh planet actually serves to help stabilize the system according to their models.

Another issue that's recently come to light that affects the habitability of the Trappist planets comes from a paper by Peter Wheately and colleagues, links to all papers in the description below. They suggest that the environment that the Trappist planets orbit in would be one with very, very high ultraviolet radiation streaming from the star. UV does not favor life as we know it, and would put some constraints on what sorts of atmospheres these planets can have.

And there's a further problem, according to a paper by K. Vida and colleagues, the Trappist -1 star displays frequent solar flares. This could mean that the atmospheres of these planets, if they have them at all, are continuously altered by the star's actvity. That too disfavors life.

On the opposite side of things, another big hurdle as far as the potential for life at Trappist -1 was the age of this star system. The Luger and colleagues paper however lays out indications from the star itself that the system is actually significantly older than originally thought with an age of between 3 and 8 billion years. This favors the potential for life, our own sun is in that age range at 4.6 billion years-old and that's proven to be enough time to produce an advanced civilization.

Civilizations are always unlikely and there is no indication whatsoever of one being at Trappist -1. But it was still worth it for SETI to take a look, however. Using the Allen Telescope Array, Seth Shostak and his colleagues searched for radio signals emanating from this system and the surrounding area. They found nothing. But that doesn't close the door for life in general, and indeed, the lack of good atmospheres might not either.

These planets orbit very close to their star, in fact they all orbit Trappist - 1 closer than Mercury orbits our sun. They also are very close to each other, a routine sight on one of these worlds would be another planet passing by appearing larger than our moon does in our sky. This would create tidal heating and perhaps subsurface oceans in the grain of Europa might be possible.

Another thing about this system that stands out is that because these worlds are so close to each other, they would be prime territory for panspermia, meaning that if one planet evolved life it could have easily been seeded to the other planets and vice versa. Multiple abodes favor life long-term.

So what of future studies of these planets? With the advent of the James Webb Space Telescope on the horizon along with European Extremely Large Telescope, we should soon have the ability to study the atmospheres of these planets in some detail. As noted in a paper by O'Malley-James and Kaltenegger, scientists will want to look for gases like ozone, if you see that one then the ultraviolet light equation changes significantly and indeed, that would be a strong indicator of life.

And, as a note for the curious, the original team investigating this world were mainly Belgian. Belgium is famous for it's many beers and Trappist is perhaps the most famous of them leading some to wonder if this system was in fact named after a beer. As it turns out, technically no.

It's named after the TRAPPIST telescope at La Silla observatory in Chile, though the team is said to have toasted the discovery with said beer. But don't feel let down, the telescope itself is named after the beer. It is a backronym to highlight the Belgian origin of the project, and rumor has it that the planets themselves are all informally nicknamed by the team after various other Belgian beers.

Thanks for listening! I am futurist and science fiction author John Michael Godier and I would like to officially announce the launch of my second channel! It's called John Michael Godier II, how's that for imaginative youtube channel names, link in the description below. It's dedicated to science fiction and the science behind it and I have already uploaded a sampling of content to explore and be sure to check out my books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live

Transcript: Trappist - 1 Update 04-05-17

This is an update in my continuing coverage of the Trappist -1 system, a fascinating solar system that could host up to 7 roughly earth-sized planets where the conditions could be right for liquid water, and thus hold the potential for life. See my other videos on this channel for more back story.

When I was a kid sitting in grade school science classes in the 1980's, I remember two scientific consensuses that stick in my mind to this day. One was that even though we had never seen one, or indeed any evidence of one, exoplanets outside our solar system almost certainly existed. There was no reason why they shouldn't, all you need to form them is a sufficient amount of solid material around a star to coalesce into planets. And that clearly happened here, so unless rocks and dust were rare in the universe it was a good bet that it happened elsewhere.

That consensus turned out to be correct, in 1992 the existence of an exoplanet was confirmed and since those days we have discovered evidence of well over 3000 planets not located in our solar system scattered among a wide variety of stars in our galaxy.

The other consensus that I remember was that, at the time, there wasn't any particular reason to think that Earth was rare. Indeed, blue jewel worlds like our own could populate the universe to such an extent that there could be untold thousands of civilizations in our galaxy alone allowing for science fiction universes like Star Trek where the discovery and contact of such civilizations was a routine, and often unpleasant and tricky, occurrence.

After all, if exoplanets turned out to be common, then why not? What would be so special about Earth? On its face, would seem like only serendipity favored it. After all, it just happens to be a certain size located at a certain distance from its star. And out of the vast multitude of stars in our galaxy alone, surely there would be many analogues of earth that took advantage of that same kind of luck. But that consensus has changed.

We know now that many things have come together to make our planet the way it is. Atmospheric composition, orbital stability, the presence of a moon to help keep earth rotating on its axis, the stability of the sun, are just a few of the many factors that make this planet an abode where complex life could evolve. Earth is probably not common at all, in fact it now seems likely that it is an extremely rare kind of world that we won't encounter much as we explore our universe.

And that leads us to Trappist - 1. This is a star system full of could be's. We see evidence of at least seven worlds that appear to be of a similar size to earth. More, they cluster in close to their dim, small red dwarf sun in such a way that, at least a portion of them, might, depending on the specific conditions present on those worlds, be able to support liquid water. Where there is liquid water, there is the possibility of life as we know it. Again, after all, we know that happened here.

A new climate model, which is no doubt one of many to come, may give us a picture of what these worlds might be like and suggest which planet astronomers should take a look at first. Also, models like this, and models of what the spectra of the planets might be like, are important because as scientists collect the data on these worlds in future years they can then compare them to the models and see which ones fit best.

According to the new model by Eric Wolf of the University of Colorado, link to his paper in the description below, the best chance for liquid water on a planet in this system would be on Trappist -1e. Wolf looked at the three most likely planets for liquid water, Trappist -1 d, e and f. In the model, the other four planets of the system didn't even come close. The farther out planets in the system would be frozen solid and the inner planets would be too hot.

Wolf modeled a variety of possible atmospheres for these three candidate worlds. To do this, he assumed that water, in whatever form, was freely available in the system. This is a reasonable assumption, the planets are modeled to have formed farther out from the star where ices are likely to have been present and then the planets migrated closer after formation. From there, he modified a model originally intended to study Earth's climate to produce the most complex model of the Trappist - 1 system we so far have.

Now, modeling planetary climates is a tricky business. Earth especially. As a result, more models are needed for a consensus to be arrived at as to what's going on with these planets. But in Wolf's model out of the three most likely candidates, only Trappist - 1e made the grade for liquid water. Planet d is too close to the star, if it had liquid water, it would simply boil off into a thick water vapor atmosphere. That should cause a runaway greenhouse effect producing a planet perhaps similar to Venus.

Planet f has the opposite problem. It's too far from the star and any water on its surface would be frozen solid. Wolf found no combination of atmospheric gases which could keep it warm enough, even carbon dioxide would freeze out according to the model. Not so with Planet e, liquid water was predicted to be possible there. But would that planet be earth-like? Not likely.

The planets at Trappist - 1 are probably tidally locked, given their proximity to their star. This means that Trappist -1e would always present the same face towards its star, much like the moon is similarly tidally locked with earth and always shows us the same face. This would create an eyeball-like world where you would have liquid water at the point on the planet that received the most light from the star. The rest would be ice. How much of the planet is conducive to liquid water is unknown, it would depend on if the sunlight is striking an ocean or a dryer continental landscape, the content of the atmosphere and so on, but perhaps around 20 percent of the surface could be earthlike in temperature.

But, as we're seeing with our own solar system, earth-like worlds are not the exclusive domain of liquid water. There are a variety of conditions, such as those of Enceladus or Europa, that could allow for subsurface liquid water. While it will be a long time before we know if such things are possible in the Trappist - 1 system, we at least know that the possibility for one potentially habitable planet more in the grain of earth is on the table.

Thanks for listening! I am futurist and science fiction author John Michael Godier currently with an upcoming book, it's called Supermind and asks if our universe is really a computer simulation and be sure to check out my other books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live.