Speaker 1: Brought to you by Toyota. Let's go places. Welcome to
Speaker 1: Forward Thinking. Hey then, and welcome to Forward Thinking the
Speaker 1: podcast and looks at the future, and says citizens of
Speaker 1: the Universe, recording angels, we have returned to claim the pyramids.
Speaker 1: I'm Jonathan Strickland and I'm Joe McCormick. Hey, Joey, you
Speaker 1: you like star gazing, right I do? And Lauren you
Speaker 1: like planets right? Um? Okay, so we've established that we
Speaker 1: are all, you know, amateur astronomers. Uh. One of the
Speaker 1: things I've always thought would be really cool would be
Speaker 1: to actually make one of those discoveries of an exoplanet. Um.
Speaker 1: You know, it's it's just an interesting idea of being
Speaker 1: able to say I have discovered the presence of another
Speaker 1: body orbiting around a distant star. So it got me
Speaker 1: to thinking, you know, how hard is that? And um,
Speaker 1: it turns out it's pretty hard. Well, it's getting easier.
Speaker 1: I mean it's certainly easier than it was a few
Speaker 1: thousand years ago. Yeah. Well a few thousand years ago
Speaker 1: I'd say it was impossible. Yes, why is that? I mean,
Speaker 1: why can't we just look up and and see planets
Speaker 1: all throughout the Milky Way for example. Well, they don't
Speaker 1: emit electromagnetic radiation the way that stars do. Yeah, well
Speaker 1: they might, they might emit some frequencies, they certainly do. Yes, No,
Speaker 1: that was a very scientifically inaccurate thing for me to say, Um,
Speaker 1: they don't emit as much, and they don't emit light
Speaker 1: their own They might get it reflected back from the
Speaker 1: star and they're going to fade away because they're very
Speaker 1: far and they're very small, and they're very dim compared
Speaker 1: to the stars. But I was actually curious when you
Speaker 1: think about exo planets. Surely somebody must have guessed at
Speaker 1: this before we detected they were there, and so who
Speaker 1: were the first people to actually suggest that there were
Speaker 1: other planets out there that were different from stars. Well,
Speaker 1: there's there's a lot of different philosophers who have talked
Speaker 1: about this, um, even before we got to the heliocentric
Speaker 1: model of our solar system. So if you want to
Speaker 1: go way back, you had a couple of chuckle heads,
Speaker 1: Aristotle and Epicurus, who were were Yeah, they were just
Speaker 1: you know, they're they're sitting there, you know, taking their
Speaker 1: lunch on the edge of giant stone work, you know,
Speaker 1: the hard hats on their heads. I get a lot
Speaker 1: of my historical knowledge from the flint stones, so uh,
Speaker 1: just roll with me on this. Anyway, they were actually
Speaker 1: having a debate, and Epicurus said that he believed the
Speaker 1: universe to be infinite, and therefore it would contain an
Speaker 1: infinity of worlds within it. By definition, if the universe
Speaker 1: is completely infinite, then everything is unnumbered. I mean, you
Speaker 1: have just a countless number of everything's, including other worlds. Um. Now,
Speaker 1: Aristotle said he believed the Earth was at the center
Speaker 1: of the universe and therefore was unique. You can only
Speaker 1: have one center, and he didn't think that because he
Speaker 1: was stupid. I mean, that was a thing that made
Speaker 1: sense to think back then, before we had telescopes and
Speaker 1: modern astronomical equipment, it really did seem like the Earth
Speaker 1: was the center of the universe. It didn't seem to move.
Speaker 1: Oh sure, sure, it seems like you're standing still and
Speaker 1: that the sky is moving around you. So therefore, yeah,
Speaker 1: obviously you're the one who's on the stationary uh rock,
Speaker 1: and everything else just moves in spheres around you and uh.
Speaker 1: As it turns out, that was a pretty popular view
Speaker 1: for a long time. Epicurus is view was not the
Speaker 1: most widely accepted Aristotles, however, was for quite some time.
Speaker 1: And um so even with epicurus view of the infinity
Speaker 1: world type of approach, it didn't necessarily mean that he
Speaker 1: thought worlds were orbiting around stars. He just thought that
Speaker 1: there would be other world olds. There are other worlds
Speaker 1: than these for my Dark Tower fans out there. Um.
Speaker 1: But then you get Copernicus coming around in saying, hey,
Speaker 1: you know what, I think the Earth is going around
Speaker 1: the Sun, not the Sun and everything else going around
Speaker 1: the Earth. And there that caused a bit of a debate,
Speaker 1: I would say, in philosophical circles. Um. Yeah, And then
Speaker 1: you get a fellow named Giordano Bruno who back in
Speaker 1: proposed that other stars might have planets of their own,
Speaker 1: just like our Sun has planets orbiting it. Uh. There
Speaker 1: were some people who disagreed with Bruno. They they took
Speaker 1: issue with what he had to say. It was the
Speaker 1: Roman Catholic Church at the time, and the way they
Speaker 1: expressed their dissenting this discending opinion was by burning him
Speaker 1: at the stake. So Bruno paid for his his belief,
Speaker 1: which turned out to be true with his life. Yeah,
Speaker 1: people were even harsher back than than they are in
Speaker 1: YouTube comments. Yeah, it's about to say it does bring
Speaker 1: a little perspective, but you know, figuratively speaking, YouTube commoners
Speaker 1: are pretty much doing the same thing to us. But
Speaker 1: figuratively alright, So at any rate, that was sort of
Speaker 1: the the If you want to look at the earliest
Speaker 1: thinkers who were putting forth this idea of other stars
Speaker 1: having planets orbiting around them, those would be the earliest
Speaker 1: ones I would point to. But these days we actually
Speaker 1: have direct evidence of planets orbiting other stars. We don't
Speaker 1: have to guess anymore. We can actually use the instruments
Speaker 1: of astronomy we've created to get data that tell us
Speaker 1: there must be other planets out there like us. And
Speaker 1: this isn't just a matter of pure curiosity. It actually
Speaker 1: bears on many other questions and science and maybe even
Speaker 1: the future of what happens to the human race. Sure, now,
Speaker 1: of course, the pure science element does matter a lot, because,
Speaker 1: as with every question in science, we can never really
Speaker 1: know how a piece of information, once gathered, might be used. Yeah,
Speaker 1: something that we know about astronomy about exceplants may prove
Speaker 1: useful in the future in ways that we don't imagine
Speaker 1: right now, even if that just means that we get
Speaker 1: a better understanding of how our universe works, which you know,
Speaker 1: some people dismiss, but that's that's just really cool. The
Speaker 1: idea that we learn things new things about how planets
Speaker 1: are formed and how how they uh you know, orbit
Speaker 1: their stars and what kind of different bodies they can orbit,
Speaker 1: or or what kind of planets are the most common,
Speaker 1: like how unusual a situation like Earth is, or how
Speaker 1: many gas giants there are, or how big or small
Speaker 1: many planets are. Yeah, yeah, very good questions. The other
Speaker 1: thing you might want to consider is how about Earth too?
Speaker 1: How about Earth too? Well. One thing you might observe
Speaker 1: looking at us in our environment is that the population
Speaker 1: of humans on the planet is consistently growing, but the
Speaker 1: planet is not getting any bigger and its resources are
Speaker 1: not multiplying. There may come a day when, in order
Speaker 1: to continue growing, the human species needs to expand beyond
Speaker 1: the planet Earth, uh well, especially to continue growing, growing
Speaker 1: in a way that's comfortable and healthy for all of us.
Speaker 1: In other words, we have to have another place to go. Yeah,
Speaker 1: And so you might look at planets in our own
Speaker 1: solar system and terror forming colonization, or you might look
Speaker 1: way beyond and say, well, is there possibility we could
Speaker 1: colonize extra solar planets planets in other solar systems throughout
Speaker 1: the galaxy? It might be more worthwhile to take a
Speaker 1: little bit of a road trip to someplace that's a
Speaker 1: lot more habitable. Yeah, maybe, depending on how fast we
Speaker 1: can get there. Well, And that's a question I think
Speaker 1: we'll look into towards the end of this podcast. But
Speaker 1: another one of the big questions that exoplanets bear on
Speaker 1: is the question of astrobiology extraterrestrial life, Right, what other
Speaker 1: life is out there beyond Earth? Is it Earth like?
Speaker 1: Is it very different from Earth life? That we we
Speaker 1: have a sample size of one planet. When it comes
Speaker 1: to life, we have no way of knowing if what
Speaker 1: we think of his life as representative of the entire galaxy,
Speaker 1: let alone the universe. So this would be a huge
Speaker 1: thing to be able to look at another planet and
Speaker 1: determine what are the what's the likelihood of life being
Speaker 1: found there? Right? I mean, just the discovery of other
Speaker 1: planets out there in the habitable zones around stars is
Speaker 1: already bearing on certain things like the question of the
Speaker 1: Fermi paradox. You've got that Drake equation we talked about.
Speaker 1: We did a podcast back. If you're not familiar, you
Speaker 1: can go check that out our podcast on the Drake equation.
Speaker 1: But it's the question of why aren't we hearing any
Speaker 1: signals from alien civilizations? Um, what's the thing that's limiting
Speaker 1: the number of alien civilizations out there? And it used
Speaker 1: to be thought that, well, maybe there just aren't enough
Speaker 1: planets in our galaxy on which alien life could arise.
Speaker 1: We now know that that variable is smashed. There are
Speaker 1: tons of planets out there, so we're actually narrowing down
Speaker 1: the question. It's got to be one of these other
Speaker 1: variables limiting the number of aliens that could be talking
Speaker 1: to us but aren't. And why do we know we
Speaker 1: need to look at planets? Well, I think we can
Speaker 1: make a pretty good guess based on physics that we're
Speaker 1: not going to find life forms in stars, not life
Speaker 1: as we know it at any rate. Yeah, where we're
Speaker 1: going to need something more or less Earth temperature. You know,
Speaker 1: water would need to be in a liquid state at
Speaker 1: least at some point during its cycle. Yeah, it's yeah,
Speaker 1: it's hard to imagine any kind of complex system like
Speaker 1: a life form existing at a temperature that a star
Speaker 1: would operate at. Yeah, I wouldn't do well in it.
Speaker 1: So let's take a look at some actual discoveries of
Speaker 1: exo planets. I want to know when was the first
Speaker 1: exo planet really actually discovered by science? All right, well,
Speaker 1: if you're looking for the first time someone pointed at
Speaker 1: at data and said, we can be definitively sure that
Speaker 1: this is coming from other planets outside of our Solar system.
Speaker 1: You know, it was just twenty years ago when we
Speaker 1: saw someone point and say, this is definitive proof that
Speaker 1: there is at least one, probably multiple planets outside of
Speaker 1: our own Solar system, and here's the data to prove it.
Speaker 1: It was a radio astronomer who discovered it back in
Speaker 1: and uh he detected two or three planet sized objects
Speaker 1: in orbit around a pulsar in the Virgo constellation. So
Speaker 1: not a star but a pulsar, which is the remnants
Speaker 1: after a supernova, so kind of interesting. It actually got
Speaker 1: some people grumbling about how it shouldn't count because the
Speaker 1: exo planets were in an orbit around the star, but um, uh,
Speaker 1: the data was from the radio telescopes he was using,
Speaker 1: and uh he was detecting, uh, the the effects of
Speaker 1: gravitational force of multiple large bodies upon that pulsar, which
Speaker 1: was what allowed him to infer that there were planets
Speaker 1: or around. Yeah, and we'll talk more about that kind
Speaker 1: of way of detecting planets in a little bit now.
Speaker 1: The first discovery of an exo plant that was actually
Speaker 1: an orbit around a star. Yeah, this dates so just
Speaker 1: one year later, and it was a pair of Swiss
Speaker 1: scientists who announced the discovery of a plant somewhere between
Speaker 1: half the size of Jupiter and two times the size
Speaker 1: of Jupiter. That's it's actually pretty tiny for for exit planets.
Speaker 1: It's also it's also uh, you know, it sounds like
Speaker 1: a huge range, but really when you're talking about galactic measures.
Speaker 1: It's so they determined that was an extremely close orbit
Speaker 1: around its parents star, which was fifty one pegasi, and
Speaker 1: its year was really really short. It's year lasts four
Speaker 1: point to earth days, so every every four point two
Speaker 1: days it orbits its Sun. Feels like it feels like
Speaker 1: a whole lot of whiplash. To me, how many years
Speaker 1: old would you? Why did you ask me that question?
Speaker 1: I would have I would have actually done the calculations
Speaker 1: that I thought about it. Um, I'm almost I'm almost. No,
Speaker 1: I'm not gonna do it. If I try and do
Speaker 1: the math, that will just come out horribly wrong. Well, anyway,
Speaker 1: they had discovered the presence of this planet again through
Speaker 1: indirect observation. They used radial velocity detection, which will also
Speaker 1: kind of talk about in a little bit. And soon,
Speaker 1: because they showed that this method was uh you know,
Speaker 1: it was a working method, soon the discoveries just started
Speaker 1: coming pretty quickly. Now, at first, like a lot. If
Speaker 1: you look back at the history of exoplanet discoveries and
Speaker 1: you're looking at stuff from the early two thousand's, they'll
Speaker 1: they'll say, like eight whole planets have been discovered so far.
Speaker 1: But over the next few years, especially once we started
Speaker 1: to really know what to look for and we had
Speaker 1: access to some pretty incredible tools, Uh, that number exploded. Um. Now.
Speaker 1: The first DEDICAD exoplanet space mission was the launch of
Speaker 1: the Corot Space Telescope in two thousand and six, the
Speaker 1: c O R O T, and it provides a continuous
Speaker 1: observation of a stellar field for a period of up
Speaker 1: to six months at a time. So it just it
Speaker 1: just keeps its uh, it's I essentially on a specific
Speaker 1: segment of space and leaves it there for like six
Speaker 1: months to see, you know, any sort of variation in
Speaker 1: the brightness of the stars that are in that stellar field,
Speaker 1: and when it starts to detect variations, it looks for patterns.
Speaker 1: So if you find a pattern in the variation of
Speaker 1: the brightness of a star that suggests that something is
Speaker 1: passing between that star and Earth on a regular basis,
Speaker 1: we'll talk more about that too. So those are kind
Speaker 1: of the early approaches or the early um the early
Speaker 1: examples of this very young field. Well, I think we
Speaker 1: should look at some of the most common methods that
Speaker 1: are used to detect extrasolar planets. Yeah, sure, Well, I
Speaker 1: think the first one we should mention, though it's certainly
Speaker 1: not the most common at this point, is simple direct imaging.
Speaker 1: I think this is what a lot of people would
Speaker 1: just guess is happening. You're just taking a picture up
Speaker 1: in the sky and you see next to a star,
Speaker 1: there's a little planet, a little dot, and there it is. Yeah.
Speaker 1: The problem is that that those dots at that distance
Speaker 1: are saying they're little is being generous, Yeah, that they
Speaker 1: just the typically don't emit enough light that's detectable at
Speaker 1: this distance and distinguishable from the star they orbit to
Speaker 1: see this. This is a problem we have at this point.
Speaker 1: It's really hard to directly image planets. There's there's also
Speaker 1: a lot of glare coming off of well, glare coming
Speaker 1: off of a nearby stars that's going to obscure direct
Speaker 1: visualization of planets like that. Yeah, though it has been done.
Speaker 1: We have card direct images of a few extra so
Speaker 1: the planets with radio waves and with infrared, I believe.
Speaker 1: But there are other methods that are have been used
Speaker 1: a lot more commonly, and one of the main ones
Speaker 1: I want to talk about is the radial velocity method
Speaker 1: is the one I had mentioned earlier with the approach
Speaker 1: with the radio telescope. Yea so true or false question
Speaker 1: t r F question for you, And you can't just
Speaker 1: draw that little thing that could be a T or
Speaker 1: an F, so we have to come down firm the
Speaker 1: whole word. Okay, true or false? The Sun is stationary,
Speaker 1: the unmoving center of gravity in our solar system. That well,
Speaker 1: I mean, I know the answer to this, and also
Speaker 1: it's in our notes, so it would be cheating. But
Speaker 1: would you would you like me to play along? Play along.
Speaker 1: I think that's true, Joe. Well, it's true. We do
Speaker 1: go around the Sun. Except it's false because the Sun
Speaker 1: is not stationary. Wait, it's both true and false. You
Speaker 1: tricked me, Because in space it actually isn't the case
Speaker 1: that a bigger object pulls a smaller object. It's the
Speaker 1: case that both objects pull each other. Yeah, the force
Speaker 1: of gravity exerts on both, on both masses. Right, So
Speaker 1: when you have two objects, it may look from one
Speaker 1: perspective that, say, Jupiter is orbiting the Sun, but in fact,
Speaker 1: both Jupiter and the Sun are orbiting the center of
Speaker 1: gravity between Jupiter and the Sun. And because the Sun
Speaker 1: is so much bigger than Jupiter, the way this typically
Speaker 1: looks is just that Jupiter is going around the Sun, right,
Speaker 1: because the Sun's size actually overlaps that edge of the
Speaker 1: center of the gravitational Furthermore, I mean the entire Solar
Speaker 1: system is moving um and our entire galaxy is moving
Speaker 1: right right, So there are several ways in which the
Speaker 1: Sun is moving. Yes, but it actually does move in
Speaker 1: response to the gravity exerted on it by its planets,
Speaker 1: And an outside observer could look in on this and
Speaker 1: notice it, especially in response to the big planets like
Speaker 1: Jupiter and Saturn. The effect is that the sun or
Speaker 1: the star seems to wobble. Yeah, it actually appears to
Speaker 1: be moving in relation to those plants. And if you're
Speaker 1: far enough out where you can't see the planets but
Speaker 1: you can see the star, you'll see that the star
Speaker 1: is wiggling a little bit, since it's doing a little
Speaker 1: bit of a chimmy. Yeah. Right, So the same is
Speaker 1: true in other solar systems throughout the galaxy. But how
Speaker 1: would we detect if a star that's dozens of light
Speaker 1: years away is just wobbling slightly in response to the
Speaker 1: gravitational pull of a planet like it would just seem
Speaker 1: like it's a pin prick. And how could you ever
Speaker 1: be sure that what you saw was a wobble and
Speaker 1: not say the fault of your instrumentation? Right, Well, you
Speaker 1: can measure it with the Doppler effect. Now we should
Speaker 1: probably explain what the Doppler effect is. Okay, so you
Speaker 1: you may remember this from physics class in high school.
Speaker 1: Any object emitting waves, which I love objects that emit waves. There,
Speaker 1: whenever something emits waves, it seems to produce higher frequency
Speaker 1: waves when it's moving towards you and lower frequency waves
Speaker 1: when it's moving away from you. And if you just
Speaker 1: picture the waves in your head, you can kind of
Speaker 1: see why this is the case. Something coming towards you
Speaker 1: is compressing the waves as it moves in your direction.
Speaker 1: Something moving away from you is stretching the waves out
Speaker 1: as it moves away. So this would be if you
Speaker 1: ever hear you know, cars going by you where they're
Speaker 1: honking the horn. You're exactly right. Yeah, the passing police
Speaker 1: car is the classic example. The sirens higher pitched as
Speaker 1: it's coming your direction after it passes by, exactly right.
Speaker 1: This is also true with light. It's not just now
Speaker 1: you know, sound is a physical acoustic wave, but electromagnetic
Speaker 1: radiation the same thing. The same principle applies. Yeah, so
Speaker 1: you can have the police radar gun. The police officer
Speaker 1: can clock the velocity of an approaching or receding vehicle
Speaker 1: by bouncing radio waves. I think it's usually microwaves off
Speaker 1: the car, so it shoots the gun, bounces the waves back,
Speaker 1: and then by calculating the difference between the outgoing waves
Speaker 1: and the waves coming back, the radar gun can detect
Speaker 1: the speed of the car. But this also works for
Speaker 1: electromagnetic waves produced by distant stars. So as the star
Speaker 1: wobbles away from us because of another object in the system,
Speaker 1: the radiation signature changes to a lower frequency, the red shift.
Speaker 1: You may have heard of this, And then when it
Speaker 1: wobbles back towards us again, the radiation signature is shifted
Speaker 1: up towards the blue frequency, the blue shift. So by
Speaker 1: studying the pattern of how the star wobbles, astronomers can
Speaker 1: actually learn a whole lot about the planet that's causing
Speaker 1: the wobbling, including a pretty good guess at its mass.
Speaker 1: But there are limitations to this kind of thing because
Speaker 1: the method depends on the gravitational poll exerted by the planet.
Speaker 1: It's best at finding relatively high mass planets closely orbiting
Speaker 1: relatively low mass stars. You remember that gravity is dependent
Speaker 1: upon two things. It's depending upon the mass of the
Speaker 1: objects in question and the distance between them. So the
Speaker 1: closer and the more massive the objects are, the more
Speaker 1: detectable this would be. Yeah, So what kind of tools
Speaker 1: our researchers using to detect this sort of thing? Essentially
Speaker 1: we're using telescopes and spectrometers. Now, a spectrometer it does
Speaker 1: is it separates the light that comes from stars into
Speaker 1: its component colors and then detect the subtle changes even
Speaker 1: when those changes are indistinguishable too. We puny mirror mortals, right,
Speaker 1: so it can detect with high precision the light frequency
Speaker 1: and how that changes as the star wobbles. In fact,
Speaker 1: there's another method that basically tracks the same effect, but
Speaker 1: in a different way. This is called astrometry. This actually
Speaker 1: dates if you're looking at the earliest of the astrometry,
Speaker 1: it dates to like nineteenth century. This is much older,
Speaker 1: and I think generally considered not not as accurate at
Speaker 1: this point. It's we we've mostly moved on to the
Speaker 1: radio velocity and to another one, but interestingly it may
Speaker 1: come back. Yeah, but I'm sorry I should say what
Speaker 1: it is. It's a way of looking for the same
Speaker 1: wobbling of planets visually. Essentially, you just look at where
Speaker 1: a star is in relation to the other stars around it,
Speaker 1: and you visually track its movement over long periods of time.
Speaker 1: As you can guess from the sound of it. That's
Speaker 1: hard to do. Yes, that sounds like you would need
Speaker 1: a really big telescope and a really high res camera
Speaker 1: in order to work that out. Yeah, I'm sure, I'm sure,
Speaker 1: photography made this a lot easier than it was before,
Speaker 1: you know, when you just had to kind of look
Speaker 1: at it and seeing, yeah, that's that's a half a degree,
Speaker 1: it's a scoch. But then there's another one where you
Speaker 1: can try to infer something about planets just by looking
Speaker 1: at the star itself. And this is probably the one
Speaker 1: that's on the rise, the one that just recently got
Speaker 1: really big, the transit method. Yeah, this is where you're
Speaker 1: looking at the light that's coming from the star and
Speaker 1: you're looking for any sort of dimming that would be
Speaker 1: indicative of a body passing between the Earth and that star.
Speaker 1: All right, a little bit like observing a solar eclipse
Speaker 1: here on Earth, where the moon is passing between you
Speaker 1: and the sun, right, except on of course, obviously on
Speaker 1: a much smaller scale because the distance is involved, uh,
Speaker 1: and and our perspective. But the idea is that we
Speaker 1: would use very precise instrumentation to measure the amount of
Speaker 1: light that's coming from a star and looking for those
Speaker 1: sort of patterns that you see a one percent dip
Speaker 1: in the luminosity of a star at certain regular intervals
Speaker 1: that could be indicative of an an orbiting body going
Speaker 1: around that start blocking some of the light. Now, obviously
Speaker 1: this depends on lots of different factors. The precision of
Speaker 1: your instrumentation is a big one, but another one is
Speaker 1: just the alignment of the planet's orbit around that star
Speaker 1: compared to where we on Earth are. Because despite what
Speaker 1: most science fiction films would have you believe, space in
Speaker 1: fact has lots of different ways that you can come
Speaker 1: at different objects. And you're not always just nos two
Speaker 1: nose in your spaceship with the other spaceships. Sometimes you're
Speaker 1: all catty wumpus with each other. Like, like we said,
Speaker 1: everything is moving. So if you you know, imagine that
Speaker 1: you are looking at the star and the planet orbits
Speaker 1: it in a way where it doesn't pass between the
Speaker 1: star and Earth, you know, the plants in orbit, uh
Speaker 1: that from our perspective, it would be like a halo
Speaker 1: around the star. Well, we're not gonna be able to
Speaker 1: see that planet because it doesn't pass between the star
Speaker 1: and us, uh, and it's too dim for us to
Speaker 1: pick up on on its own. So the transit method
Speaker 1: would not work for those kind of planets. So for
Speaker 1: any system that is in a in that sort of
Speaker 1: alignment in respect to where we are, that's great, But
Speaker 1: for all the ones that aren't, we have to use
Speaker 1: some other methodology. What about gravitational micro lensing. This is
Speaker 1: another kind of rising in popularity method and it's sort
Speaker 1: of parallel to this transit method, but instead of looking
Speaker 1: for a dimming, we're looking for a brightening UM And
Speaker 1: let me explain how how the heck that works. UM. So,
Speaker 1: so what's going on is that we've got two star
Speaker 1: systems that we're looking at, one distant and one really
Speaker 1: bloody distant UM. And when the nearer one passes between
Speaker 1: us and the farther one, the nearer one's gravity bends
Speaker 1: and magnifies the light that's coming from the farther one
Speaker 1: like a lens. So the farther star appears to smoothly
Speaker 1: brighten and fade over a period of a few weeks
Speaker 1: or a few months UM. And this is pretty nifty
Speaker 1: unto itself. So where do exo planets come in? You
Speaker 1: might ask, Well, if the if the nearer star system
Speaker 1: contains a planet, that planet's gravity can cause hitches in
Speaker 1: the brightening and fading pattern, or even cause a sort
Speaker 1: of lens flare. Almost this type of probably UM and
Speaker 1: this method is is really read for for finding smaller,
Speaker 1: potentially Earth sized exo planets um, which in turn is
Speaker 1: important in our search for extraterrestrial life as we know it.
Speaker 1: As we said near the top of the show. Um. However,
Speaker 1: it's a little bit tough to use this method to
Speaker 1: tell the exact mass of the extra planet in question, UM.
Speaker 1: And and that's because okay, so, so researchers can use
Speaker 1: their observations to determine the ratio of the masses of
Speaker 1: the planet and its star pretty easily, but they have
Speaker 1: to make an educated guess about the actual mass of
Speaker 1: both based on statistical modeling and um any other electromagnetic
Speaker 1: observations that they can make about the stuff. So, uh,
Speaker 1: it's it's imprecise in that way. Interesting. That is interesting.
Speaker 1: And I want to ask about a weird thing about
Speaker 1: robe planets. You'll heard about these. Yeah, I love that
Speaker 1: you kept my note in here, which first of all,
Speaker 1: they can't touch other plants where they will totally steal
Speaker 1: those planets superpowers. Well, okay, hold on a second. Almost
Speaker 1: all the methods we're talking about here, except the direct imaging,
Speaker 1: are involving how a plan in it affects our view
Speaker 1: of a star right, that's how we gathered the data
Speaker 1: about it. So how can you do so if you
Speaker 1: have a planet that's floating out there in the middle
Speaker 1: of interstellar space, which not orbiting a set is definition yes,
Speaker 1: orbiting the galaxy center directly instead of orbiting a star,
Speaker 1: can you see it? Is there a way or not
Speaker 1: see it? But is there a way you can determine
Speaker 1: it's there and learn anything about it? Okay, So so
Speaker 1: rogue planets to to really break it down here, UM
Speaker 1: are not orbiting a star for for one of several reasons. UM.
Speaker 1: They could have escaped their stars orbit, either due to
Speaker 1: the pull of a nearby star or due to their
Speaker 1: star going red giant perhaps and and pushing its planets
Speaker 1: out UM. Or they might have formed out in the
Speaker 1: interstellar dust UM and just didn't have enough mass to
Speaker 1: start fusing hydrogen and thus become a star. Or and
Speaker 1: thank you guys for leaving my joke in here, they
Speaker 1: might have just rolled really high on dexterity UM. So
Speaker 1: so they're not So they're not very near um any stars,
Speaker 1: meaning that hey probably not obscured by light from a star,
Speaker 1: which is cool UM, but they're probably not illuminated much
Speaker 1: at all, which does make them tough to see UM,
Speaker 1: but researchers can use UH telescopic cameras with filters that
Speaker 1: select for certain segments of the spectrum UM and then
Speaker 1: scan darker areas of the sky UH. At that point,
Speaker 1: redder colors are going to indicate cooler bodies like either
Speaker 1: brown dwarves, which are similarly formed when clouds. OH. Interstellar
Speaker 1: stuff don't get dense enough to become stars, although they
Speaker 1: are way bigger than planets, even like gas giants like
Speaker 1: Jupiter UM or it could indicate an exoplanet. So have
Speaker 1: we actually seen any road planets? Thousands have been identified
Speaker 1: in the last ten years or so, and some researchers
Speaker 1: think that there could be billions. In any single given
Speaker 1: nebula um. There might be a dozen that are less
Speaker 1: than a hundred light years away from us right now.
Speaker 1: I just like the whole part where you talked about
Speaker 1: the scan darker areas of the sky because it made
Speaker 1: me think that you have to put it through a
Speaker 1: scanner darkly. Oh yeah, well this is this is the
Speaker 1: nerdiest entry in our outline. Excellent. I didn't put that
Speaker 1: in the notes though, so it was just me being obnoxious. Okay. So,
Speaker 1: so road planets are really fascinating, especially because we're not
Speaker 1: entirely sure how they got out there. But they're perhaps
Speaker 1: less interesting than some solar bound planets because it's less
Speaker 1: likely that they're going to contain life as we know it.
Speaker 1: I actually, uh, it would seem like that, but I
Speaker 1: feel like I've read stuff saying that maybe they could
Speaker 1: contain life, like they might be warmer than we would imagine. Speaking,
Speaker 1: I don't know, no, and I mean I mean space,
Speaker 1: space is warm. Space is not cold, as we have
Speaker 1: mentioned on the show before. So I'm just trying to
Speaker 1: figure out where the energy source would come from. Geothermal
Speaker 1: you know, like deep see events. Yeah, it's possible. I
Speaker 1: suppose radiators, it's just what Unfortunately I can't remember where
Speaker 1: I've read that now, and our WiFi is out so
Speaker 1: I can't look it up. Yes, technology, um okay, But
Speaker 1: so speaking of technology, what what about the future? Um?
Speaker 1: Where where is this research going? Well? Recently, in our
Speaker 1: podcast about telescopes, we talked about how some upcoming telescopes
Speaker 1: might really help in the search for exoplanets, especially stuff
Speaker 1: like the James Web Space Telescope, and how that might
Speaker 1: use infrared to teach us a lot about what exoplanets
Speaker 1: are out there, and that's really exciting. Sure, but there
Speaker 1: are also other methods that could be coming up well,
Speaker 1: and some of them are dependent upon things that we
Speaker 1: can't necessarily, ever ever say are going to be you know,
Speaker 1: evident to us, right, like gravitons. That's so you're using
Speaker 1: your hypothetical particle. Friend. Well, you asked a hypothetical question,
Speaker 1: you get a hypothetical answer. So I like all my
Speaker 1: hypothetical friends. They're are the less said about my hypothetical
Speaker 1: friends the better? All right? No, No, the reason why
Speaker 1: I mentioned gravitons is so gravitons, that's that's kind of
Speaker 1: like our placeholder. Yeah, so you have particles that mediate
Speaker 1: the other forces of the universe, like electromagnetic force, Um,
Speaker 1: you have the photon. So gravitons are supposedly the hypothetical
Speaker 1: particle that we think might mediate the force of gravity.
Speaker 1: We've never found this particle if it exists, right, we don't.
Speaker 1: We don't have any way of directly observing that this particle,
Speaker 1: if it does exist so far. But you know, it's
Speaker 1: one of those things that we have kind of to
Speaker 1: make the math work. I mean, that's that's a simple
Speaker 1: way of saying it. But in order for us to
Speaker 1: describe things that are going on, it's a very useful
Speaker 1: hypothetical particle. But if it is a real particle and
Speaker 1: we found a way to detect them, than anything that
Speaker 1: has a gravitational field hypothetically is giving off these gravitons,
Speaker 1: and so if we could observe them, we could observe
Speaker 1: lots of stuff. Yeah, I like to think of it
Speaker 1: like the scene in The Matrix where Neo is suddenly
Speaker 1: able to see the entire world as the series of
Speaker 1: ones and zeros and can actually then manipulate it. We
Speaker 1: wouldn't be able to necessarily manipulate anything through gravitons, but
Speaker 1: we might be able, through this kind of detection process,
Speaker 1: be able to to see the presence of stuff out
Speaker 1: there that we never would have picked up on before.
Speaker 1: It would it would lead to a true explosion of
Speaker 1: discoveries and would be incredibly useful for things like, you know,
Speaker 1: detecting asteroids, things that could potentially cause us lots of issues. Now,
Speaker 1: all of that obviously depends upon a hypothetical particle turning
Speaker 1: out to be a real thing that we can actually
Speaker 1: directly observe, and that may very well never be the case.
Speaker 1: It may always be the case that we only observe
Speaker 1: the effects of gravity through the actual interaction of masses
Speaker 1: in space. It would not be you know, viewing the
Speaker 1: actual particle, hypothetical or otherwise. So it's a huge If
Speaker 1: I have a question, please ask it. We're all talking
Speaker 1: about planets within our own galaxy, the Milky Way, are
Speaker 1: our little neighborhood of the universe. Yeah, I just want
Speaker 1: to make sure I'm correct in assuming that it would
Speaker 1: be absolute madness to think we could detect something as
Speaker 1: small as a planet in another galaxy, right right? No, no, no,
Speaker 1: that is not absolute madness. Is it really possible that
Speaker 1: somebody might be able to detect a planet in, say,
Speaker 1: the closest galaxy to us. Some researchers think that we
Speaker 1: already have whoa tell me about it? WHOA? Indeed? Um? Okay, So,
Speaker 1: remember when I was talking about gravitational micro lensing. Some
Speaker 1: scientists out of the University of Zurich in Switzerland think
Speaker 1: it's possible to use the same method to detect planets
Speaker 1: in Andromeda, being our nearest galactic neighbor. But you know,
Speaker 1: still being more than two million light years away. Um,
Speaker 1: other galaxies. I mean, just so y'all know, I mean
Speaker 1: you might not have a sense of cosmic scale. That's
Speaker 1: so far away. It's not close enough, way way out.
Speaker 1: I mean you might think it's a real walk to
Speaker 1: get down to the chemist, but that's just peanuts compared
Speaker 1: to space. Yeah, it's way too far away for us
Speaker 1: to even pick out individual stars, um, even with our
Speaker 1: most impressive telescopes. So instead of looking at stars here,
Speaker 1: they're looking at pixels, each of which contain the light
Speaker 1: from several stars. And and they can they can use
Speaker 1: that same method of brightening to try to determine when
Speaker 1: weird stuff is happening. You mean, the gravitational micro lens.
Speaker 1: The gravitational micro lensing, right, So, so something something passing
Speaker 1: in front of something else and and causing the light
Speaker 1: of the farther thing to bend and appear more bright. Um.
Speaker 1: The concept of using this two look at other galaxies
Speaker 1: is really pretty young, definitely less than ten years old.
Speaker 1: But um, this group out of Switzerland thinks according to
Speaker 1: their simulations of what this lensing would look like run
Speaker 1: against some previous telescope data from Andromeda that they may
Speaker 1: have actually observed an exit planet way back in two
Speaker 1: thousand four. Um. They suggested at the time that it
Speaker 1: was a binary star, but yeah, yeah, based on on
Speaker 1: the simulation, it might have been a planet some six
Speaker 1: or seven times the massive Jupiter. That is incredible, And
Speaker 1: just think that's like, that's just ten years after the
Speaker 1: first discovery of an exoplanet. Period. Yeah, that's in our galaxy. Now,
Speaker 1: of course that's not confirmed, right, Yeah, And unfortunately there's
Speaker 1: really no way to check it because of all of
Speaker 1: these complex movements of planets and solar systems and galaxies.
Speaker 1: It means that that these lensing events do not repeat. Right.
Speaker 1: We can't just train a telescope on that segment of
Speaker 1: and wait for it to happen again. Yeah, So clearly
Speaker 1: what we have to do send someone out the check
Speaker 1: and come back, uh yeah to two million light years
Speaker 1: away or saying that's that's no big Yeah. Well, uh,
Speaker 1: you know. One of the other things we mentioned was
Speaker 1: this this search for actual extraterrestrial life. But how would
Speaker 1: you look for life on exo planets. I mean, as
Speaker 1: we were saying earlier, you're not going to resolve them
Speaker 1: up to the point where you can look at the
Speaker 1: surface and see little people walking around. You look for
Speaker 1: activity on a Friday night, that's when life is always
Speaker 1: at its most active. No, actually, we're talking about looking
Speaker 1: for bio signatures, which are evidence of things that life
Speaker 1: as we know it generates on a planet. And when
Speaker 1: I again when I say life as we know it,
Speaker 1: we're talking about the sample size of one planet. But
Speaker 1: we know at least this is one way it could work, Yes,
Speaker 1: and we know that there are certain things that are
Speaker 1: likely to have been made by something that was alive
Speaker 1: versus something that was not a life like there's some
Speaker 1: gases that we could detect, but we wouldn't necessarily know
Speaker 1: if it came from an organic life form or a
Speaker 1: geological event, right, So, so those would be problematic. Even
Speaker 1: if we detected it, we could never say, for not
Speaker 1: even with any degree of certainty, that it came from
Speaker 1: life forms, because it could have come from some other source. Sure,
Speaker 1: but one example would be oxygen, because it's not natural
Speaker 1: for Earth to have oxygen. If y'all didn't know this,
Speaker 1: Earth is not naturally an oxygen planet. The oxygen in
Speaker 1: our atmosphere is largely a byproduct of life on Earth exactly,
Speaker 1: So oxygen would be one of those biosignatures we would
Speaker 1: look for. There are other ones as well, but these
Speaker 1: are the sort of things that we would try and detect. Now,
Speaker 1: then the question becomes, hey, how do you find out
Speaker 1: that that planet that's really far away has oxygen on it?
Speaker 1: I mean, that doesn't really answer our question. Can lean
Speaker 1: out and try to breathe it? Nope. So the way
Speaker 1: we detect biosignatures is through spectral analysis, again using spectrometers,
Speaker 1: looking at the color of light that's coming off of
Speaker 1: being you know, reflected off of that planet. So, uh,
Speaker 1: when we do that, when we look at the light
Speaker 1: that we can see coming from these planets being reflected
Speaker 1: off of them, obviously they're not emitting the light themselves.
Speaker 1: Then you start to work backwards and say, all right, well,
Speaker 1: what ingredients had to be there for these particular wavelengths
Speaker 1: of light to make it to us? Right? Because different
Speaker 1: types of atoms will reflect light at different wavelengths and
Speaker 1: they will absorb other wavelengths, right, So you would expect
Speaker 1: to see an absence of certain ones with the presence
Speaker 1: of certain gases. And because that's predictable, you know, a
Speaker 1: particular gas is always going to absorb the same wavelengths
Speaker 1: of light. Then we can start to work backwards that way.
Speaker 1: So we've really looked for the dominant biosignatures that we
Speaker 1: found on Earth, because that's again what we have we
Speaker 1: know to work with. There may very well be other
Speaker 1: types of life out there that are very different from
Speaker 1: what we see on Earth, but because we have an
Speaker 1: honored them, we can't know what to look for in
Speaker 1: that case. So it becomes kind of a cyclical problem.
Speaker 1: So we're looking specifically for stuff that is similar to
Speaker 1: what we see here on Earth. Okay, So I want
Speaker 1: to talk about one more thing and follow up on
Speaker 1: that question we had earlier about colonizing exo planets, because
Speaker 1: this comes up a lot when people talk about exoplanets.
Speaker 1: We got to find the habitable exo planet, you know,
Speaker 1: where's the one we could go live out our our
Speaker 1: our peaceful retirement in the galaxy. I don't know how
Speaker 1: realistic that is, and I don't want to be a
Speaker 1: naysayer because who knows what kind of spacecraft and and
Speaker 1: propulsion systems will come up with in the future. But
Speaker 1: based on the kinds of spacecraft we have today, I'm
Speaker 1: not sure that that's a realistic thing to talk about. Okay,
Speaker 1: so what are your objections here, Joe? I mean, what's
Speaker 1: what's the issue? Are you just think we don't have
Speaker 1: a style and enough ride? Yeah, what does a fast
Speaker 1: moving human spacecraft look like? Well, we could look at
Speaker 1: Voyager one. It is like a one ton object that's
Speaker 1: fleeing our Solar system very very fast. It's one of
Speaker 1: the fastest things. I think it is currently the the
Speaker 1: fastest spacecraft. Um, so we may have had something that
Speaker 1: that I think was a little bit faster spiraling into
Speaker 1: the Sun, but right right now it's going very fast
Speaker 1: and we don't necessarily want to do the spiral into
Speaker 1: the Sun. Well, it got a boost, and this wasn't
Speaker 1: just drive systems. It got a very lucky boost by
Speaker 1: doing swing buys of Jupiter and Saturn, which sped it
Speaker 1: up significantly. It took advantage of their gravity to get
Speaker 1: itself thrown out into space. There their gravity in their
Speaker 1: own orbits. Yeah, kind of slingshot up right out. Yeah,
Speaker 1: the old star trek methodology and going back in time. Right,
Speaker 1: so it's going more than thirty five thousand miles per hour,
Speaker 1: which is really fast. I've even seen some figures putting
Speaker 1: it closer to forty miles per hour today. I'm not
Speaker 1: sure I've seen different figures, but let's just round up
Speaker 1: for simplicity and say you had a crew full of
Speaker 1: colonists who are in a spacecraft heading out from Earth
Speaker 1: at fifty thousand miles per hour. I did a little
Speaker 1: math with the help of Google and Wolf from Alpha,
Speaker 1: to see how long it would take to get to
Speaker 1: an exo planet. So I looked at Glies six sixty
Speaker 1: seven c C, which is one of the ones they've
Speaker 1: held up, is sort of one of the one of
Speaker 1: the really cool looking, possibly habitable planets. It's about twenty
Speaker 1: two light years away, so it's one of the closer ones.
Speaker 1: One light year is about five point eight seven eight
Speaker 1: times ten to the twelve miles. That's that's very very far.
Speaker 1: And that's that's just one light year. You said this
Speaker 1: one was twenty two lights. Twenty two light years is
Speaker 1: one point twenty nine times ten to the fourteen miles,
Speaker 1: or about a hundred and twenty nine trillion miles. Okay,
Speaker 1: so then you take a hundred twenty nine trillion miles
Speaker 1: divided by are you using the generous speed or the
Speaker 1: I'm using the super generous fifty thousand miles per hour,
Speaker 1: which is about four hundred and thirty eight million miles
Speaker 1: per year. A fifty miles per hour, it would take
Speaker 1: two hundred nine thousand, three hundred and twenty five years
Speaker 1: to reach this exo planet I just mentioned. That's longer
Speaker 1: than Homo sapiens has been a species. So so there's
Speaker 1: no telling what what the inhabitants of said spaceship would
Speaker 1: be by the time they reached this exo planet. My
Speaker 1: thought was, at that point, you're not you're not actually
Speaker 1: colonizing the planet. You're colonizing the spacecraft itself, right, and
Speaker 1: you're probably the face of bow by the time you
Speaker 1: get there. So yeah, humans would essentially evolve to favor
Speaker 1: the conditions of the spacecraft before they reached the new planet.
Speaker 1: By the time they got there, they might not want
Speaker 1: the planet. They might just need to live on the spacecraft.
Speaker 1: They might be afraid of the planet. So the moral
Speaker 1: of the story to me is that unless we invent
Speaker 1: much much faster spacecraft that can travel faster than light,
Speaker 1: or at least some really significant fraction of the speed
Speaker 1: of light, exo planet colonization and is just off the table.
Speaker 1: Like if you were able to get close enough so
Speaker 1: that you're talking about a generation or maybe two generations
Speaker 1: of people to get to the closest exoplanet, I could
Speaker 1: see that being a possible. Yeah, but if you're talking
Speaker 1: longer than humans have been human, then that is an
Speaker 1: issue totally. Yeah, it's not a really good Plan B.
Speaker 1: That's maybe a Plan X or Plan data Alpha. Well,
Speaker 1: what this comes down to is basically, if you're thinking,
Speaker 1: oh no, we're about to use up Earth, you either
Speaker 1: need to figure out how to tear aform Mars, or
Speaker 1: you need to invent some spacecraft that can travel near
Speaker 1: or faster than the speed of light, or you got
Speaker 1: to figure out how to stop using up Earth exactly right. No,
Speaker 1: I'm taking it as a given. And you're like, we're
Speaker 1: not going to stop, can't stop, cann't stop, won't stop
Speaker 1: to say, black Fridays around the corner. Let the good
Speaker 1: times roll right right right? All right, So so maybe
Speaker 1: that's not our super best option, right No, I actually
Speaker 1: I agree entirely with what you said. I mean, it's
Speaker 1: it's a no brain or the smartest thing to do
Speaker 1: is to make use of the resources we have in
Speaker 1: a smarter way. But but but that's easier said than done, obviously,
Speaker 1: but not Nonetheless, it would be really cool for us
Speaker 1: to find some potentially habitable planets and uh, you know,
Speaker 1: like send him a Facebook message like saying like, hey, guys,
Speaker 1: what's up. Yeah, that was actually one of the things
Speaker 1: I was thinking of. Two is that it you know,
Speaker 1: discovering these exoplanets and finding candidates that could potentially support
Speaker 1: life might mean that we don't ever you know, inhabit
Speaker 1: them ourselves, because they're so far away that to get
Speaker 1: there would have this prohibitively long journey. But maybe if
Speaker 1: we do discover one that has intelligent life on it,
Speaker 1: that we could one day communicate was said intelligent life. Um.
Speaker 1: And keeping in mind this communication would still take an
Speaker 1: incredly long time because even traveling traveling at the speed
Speaker 1: of light, like your example that you had, Joe, that's
Speaker 1: twenty two years between messages. I send a message out
Speaker 1: I have that, I'm gonna wait twenty two years before
Speaker 1: it even gets to the person I texted, and then
Speaker 1: I have to wait for them to you know, the
Speaker 1: message and the winky smiley face twenty two more years
Speaker 1: for me to get the winkie smiley face. By then,
Speaker 1: the movie I was trying to see has already left
Speaker 1: the theater, so it's just not the But but this
Speaker 1: is one of those ways where we could potentially actually
Speaker 1: have a communication with with another intelligent species. But that
Speaker 1: would one depend on they're actually being one out there too.
Speaker 1: We'd have to find it, and then three we'd have
Speaker 1: to be able to send some sort of communication that
Speaker 1: they could identify as communication, and four we'd have to
Speaker 1: agree that that's a smart thing to do. Well, if
Speaker 1: they're that far away, it's not really likely that they're
Speaker 1: going to catch up to us anytime soon, unless at
Speaker 1: least twenty two years to work at the at the
Speaker 1: very least, and more likely three hundred thousand years to
Speaker 1: work with. So I think if you've got three hundred
Speaker 1: thousand years to work with, you you could really say, like,
Speaker 1: I'm pretty sure by the time they get to wherever
Speaker 1: we are, we will be able to handle it. We've
Speaker 1: been training for three hundred thousand years for this, so
Speaker 1: at any rate. It was an interesting discussion and it
Speaker 1: was really interesting to learn how how scientists are detecting
Speaker 1: these exo plants I've always heard about it kind of
Speaker 1: in passing whenever a new discovery comes around, but I
Speaker 1: never really looked into it seriously on a deeper level.
Speaker 1: And it's truly as an amazing field and I can't
Speaker 1: wait to learn more about it just because I mean, again,
Speaker 1: bottom line, we're learning more about how our universe works,
Speaker 1: which is always cool. So any final thoughts, guys on
Speaker 1: exo Planets, do you want to talk about Planet Pooplon
Speaker 1: No Populonula poople on because it's it's planet. You're messing
Speaker 1: my head up now, Jonathan, No, shout out to all
Speaker 1: the puppies on Planet Populan. Your planet is the best one.
Speaker 1: I'm sure. If if anyone in our galaxy gets preserved,
Speaker 1: I hope it's that one. All right, that's fair. I'm
Speaker 1: sure that all the cats on the internet are cursing
Speaker 1: your name, but we will we will ignore that and
Speaker 1: soldier on. So, guys, if you out there have any
Speaker 1: suggestions for future episodes, be forward thinking. There's something you've
Speaker 1: always wanted to know about. Maybe there's even a question
Speaker 1: you have about this exo planet episode we've just done.
Speaker 1: You should send it into us. Let us know we
Speaker 1: love your messages keep them coming. You can contact us
Speaker 1: on Twitter, on Facebook, or on Google Plus. On Twitter
Speaker 1: and Google Plus, we use the handle f w Thinking.
Speaker 1: Just search for fw thinking over at Facebook. We'll pop
Speaker 1: right up and leave us a message, and we'll talk
Speaker 1: to you again, really soon m H. For more on
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