Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
Speaker 1: with our soothing Bedtime Astronomie podcast. Each episode offers a
Speaker 1: gentle journey through the stars, planets, and beyond, perfect for
Speaker 1: unwinding after a long day. Let's travel through the mysteries
Speaker 1: of the universe as you drift off into a peaceful
Speaker 1: slumber under the night sky.
Speaker 2: You know the image, I mean, it's basically burned into
Speaker 2: our brains at this point, the pale blue dot.
Speaker 3: Oh yeah, Voyager one, Carl Sagan's whole speech. It's iconic.
Speaker 2: It is right, that one tiny pixel of light just
Speaker 2: hanging there in a sunbeam, and for what the last
Speaker 2: thirty plus years, that's been our shorthand for life in
Speaker 2: the universe. If you look for aliens, you look for
Speaker 2: the blue, you look for oceans, you look for that
Speaker 2: specific shade that says earth like. It's almost romantic.
Speaker 3: It is. It's a beautiful thought, but it's also well,
Speaker 3: it's a bit of a trap. A trap how so,
Speaker 3: it's a cognitive trap because it locks us into looking
Speaker 3: for a mirror. We're looking for ourselves, but ourselves today.
Speaker 3: It just assumes that habitable always equals blue, and that
Speaker 3: is exactly where we're going today.
Speaker 2: I want you to just for a second reimagine that dot.
Speaker 2: Forget the blue. Instead, picture of that pixel is a deep,
Speaker 2: vibrant purple.
Speaker 3: Or get this, What if the oceans on that dot
Speaker 3: weren't blue at all, but like a bright, almost neon green.
Speaker 2: And here's the kicker. This isn't science fiction. We're not
Speaker 2: talking about some far flown alien world.
Speaker 3: Yeah, no, not at all. We are talking about Earth.
Speaker 3: This is our own history. If alien astronomers had been
Speaker 3: looking at our planet at different times, they wouldn't have
Speaker 3: seen a pale blue dot.
Speaker 2: They have seen a purple world, oh or a green
Speaker 2: ocean world.
Speaker 3: And that simple fact that our planet changes its color
Speaker 3: over billions of years is at the heart of this. Well,
Speaker 3: this really intense debate happening inside NASA right now.
Speaker 2: It's a huge struggle. We're talking about giant space telescopes,
Speaker 2: million dollar budget fights, ancient bacteria, and even rocks that
Speaker 2: are trying to trick us exactly. We're looking at a
Speaker 2: new white paper that just came out January twenty twenty
Speaker 2: six on the Arts of pre Print Server. It's from
Speaker 2: the Living World's Working group.
Speaker 3: Which is a very very cool name for a committee
Speaker 3: of scientists.
Speaker 2: It sounds like a superhero team, doesn't it. But their
Speaker 2: job is actually really practical. They're trying to define the
Speaker 2: capabilities of the next great space telescope, the Happible World's
Speaker 2: Observatory or HWO.
Speaker 3: Right, and the argument they're making in this paper is,
Speaker 3: to put it simply, if we build this thing on
Speaker 3: the cheap, if we cut corners on the sensors to
Speaker 3: save a few.
Speaker 2: Billion dollars, which always happens.
Speaker 3: It always happens, then we might stare right at a
Speaker 3: living planet and have absolutely no idea what we're looking at.
Speaker 2: Or and I think this might be worse, we might
Speaker 2: stare at a dead, toxic rock and convince ourselves we
Speaker 2: found a jungle.
Speaker 3: That's the fear, that's the big false positive nightmare.
Speaker 2: So that's the mission today. We're going hunting for purple earths,
Speaker 2: green oceans, and the cosmic impostors trying to fool us.
Speaker 3: Let's do it.
Speaker 2: Okay, So before we even get to the cool biology,
Speaker 2: the purple bacteria and all that, we haven't talked about
Speaker 2: the machine, the tool, this Habitable World's Observatory.
Speaker 3: The HWO yeah.
Speaker 2: I mean, we've all been obsessed with the James Web
Speaker 2: Telescope JWST for the last few years. The images are
Speaker 2: just stunning. So why do we need another huge, expensive telescope.
Speaker 2: What can HWO do that Web can't.
Speaker 3: That is the multi billion dollar question, isn't it? And
Speaker 3: it really comes down to how they look at planets.
Speaker 3: JWST is an absolute marvel, don't get me wrong, but
Speaker 3: for exoplanets planets around other stars, it mostly uses a
Speaker 3: method called transit spectroscopy.
Speaker 2: Transit's okay, so that's the shadow method.
Speaker 3: Right, The shadow method exactly, you have to wait for
Speaker 3: a planet to pass directly in front of its star
Speaker 3: from our point of view.
Speaker 2: And as it does, a tiny bit of the starlight
Speaker 2: shines through the planet's.
Speaker 3: Atmosphere precisely like sunlight through a stained glass window, and
Speaker 3: by looking at what colors get filtered out, you can
Speaker 3: tell what gases are in that atmosphere. Oh, there's methane here,
Speaker 3: there's water, vapor. It's incredible, Like there's a butt, there's
Speaker 3: a big butt. You're only seeing the edges. You're basically
Speaker 3: looking at a backlit silhouette of the planet. You're sniffing
Speaker 3: its air, but you're not seeing its surface.
Speaker 2: You can't see the ground.
Speaker 3: You can't see the ground. The Habitable World's Observatory is
Speaker 3: designed to do something much much harder. It's designed for
Speaker 3: direct imaging.
Speaker 2: Which sounds simple. It just means taking a picture of
Speaker 2: the planet itself.
Speaker 3: It sounds simple. We take pictures all day, but the
Speaker 3: physics of it are just staggering. You're trying to photograph
Speaker 3: a tiny firefly floating right next to a giant, blinding searchlight.
Speaker 2: From miles and miles away.
Speaker 3: From light years away. The star is billions of times
Speaker 3: brighter than the planet. If you just point a telescope,
Speaker 3: the planet is completely lost in the glare.
Speaker 2: So how do you solve that? What's the trick?
Speaker 3: The trick is a very clever piece of engineering called
Speaker 3: a coronagraph. A coronagraph, Yeah, think of it this way.
Speaker 3: If you're outside and the sun is in your eyes,
Speaker 3: but you want to see, I don't know, a bird
Speaker 3: flying near.
Speaker 2: It, what do you do instinctively and put my hand
Speaker 2: up block the sun with my thumb.
Speaker 3: Exactly, you create a tiny artificial eclipse just for your eye.
Speaker 3: A coronagraph is a super high tech hand inside the telescope.
Speaker 3: It's a system of masks and mirrors that physically block
Speaker 3: the light from the star.
Speaker 2: So it creates a little shadow right where the star is.
Speaker 3: A perfect little shadow. It suppresses that glare by an
Speaker 3: insane amount, like it blocks ninety nine point nine percent
Speaker 3: of the starlight, and suddenly the faint little speck of
Speaker 3: light reflecting off the planet next to it can actually
Speaker 3: be seen.
Speaker 2: And that's the revolution, because if you can block the star,
Speaker 2: you're not just seeing the atmosphere anymore.
Speaker 3: Now you're seeing the surface.
Speaker 2: You're seeing the light bouncing off the continents, off the oceans.
Speaker 2: You can actually see its color.
Speaker 3: And that's where all the trouble starts because seeing color
Speaker 3: sounds easy, but to do it from that distance, you
Speaker 3: need incredibly clean data. The whole point of this new
Speaker 3: white paper is that the aged needs an exceptionally high
Speaker 3: signal to noise ratio signal to noise.
Speaker 2: We talk about that in audio production. So it's about clarity.
Speaker 3: It's all about clarity. It's not just about getting more light,
Speaker 3: it's about getting clean light. Imagine you're at a really
Speaker 3: loud concert and someone across the room is trying to
Speaker 3: whisper a secret password to you, Okay, The loud music
Speaker 3: is the noise, all the stray light from the star,
Speaker 3: from dust in space, even heat from the telescope itself.
Speaker 3: The whisper is the signal, that little sliver of colored
Speaker 3: light that might indicate life.
Speaker 2: And if the signal to noise is low, the music
Speaker 2: is too.
Speaker 3: Loud, you can't hear the password. You might hear a murmur,
Speaker 3: You might think they said the right word, but you
Speaker 3: can't be sure. The scientists are saying they need a
Speaker 3: system so quiet, so sensitive that they can pick out
Speaker 3: that whisper with total confidence.
Speaker 2: And this gets us back to the horse trading you mentioned,
Speaker 2: because making a quiet telescope is.
Speaker 3: Expensive, unbelievably expensive. Every little bit of improved performance costs
Speaker 3: millions or tens of millions, and the financial managers at NASA,
Speaker 3: their job is to look at the plans and say, Okay,
Speaker 3: do you really need the deluxe sensor package. Can't you
Speaker 3: just make do with the standard one cage?
Speaker 2: Just fix it in photoshop later.
Speaker 3: Exactly, And this paper from the Living World's Group is
Speaker 3: their response. It's them saying, look, this isn't a luxury feature,
Speaker 3: this isn't just gold plating. If we don't have this
Speaker 3: specific capability, the entire mission could fail. We won't be
Speaker 3: able to hear the whisper.
Speaker 2: Okay, so let's get into what they're trying to hear.
Speaker 2: What's the whisker? If an alien astronomer is looking at
Speaker 2: Earth right now, what's the gold standard signal that screams life.
Speaker 3: For modern Earth? The clearest, most unambiguous surface biosignature is
Speaker 3: something called the vegetation red edge.
Speaker 2: The red edge, it sounds like a spy movie, A.
Speaker 3: Cliff is actually the best way to think about it.
Speaker 3: So we all know plants are green because chlorophyll absorbs
Speaker 3: red and blue light for photosynthesis.
Speaker 2: Right right, and it reflects the green light, which is
Speaker 2: why we see it as green.
Speaker 3: But that's not the whole story. There's something else happening
Speaker 3: that our eyes can't see. Plants are also reflecting a
Speaker 3: huge amount of near infrared light.
Speaker 2: Okay, why, what's the evolutionary advantage there?
Speaker 3: It's a radiator, it's thermal regulation. Infrared light is basically heat.
Speaker 3: If plants absorbed all that infrared energy from the sun,
Speaker 3: they literally cook themselves from the inside out.
Speaker 2: Ah, So they need to get rid of it.
Speaker 3: They need to get rid of it fast. So they
Speaker 3: evolved this amazing trick where their cell structures act like
Speaker 3: perfect mirrors for a near infrared light. They just bounce
Speaker 3: it right back into space.
Speaker 2: That's genius, it is.
Speaker 3: And if you plot this on a graph of light,
Speaker 3: a spectrogram, it creates this incredibly dramatic feature. The brightness
Speaker 3: is low in the red part of the spectrum because
Speaker 3: the plants are eating that light. And then as soon
Speaker 3: as you cross over into the near infrared, boom, the
Speaker 3: line shoots straight up like a vertical wall, a cliff,
Speaker 3: a cliff. That sharp sudden jump is the vegetation red edge.
Speaker 2: And rocks don't do that.
Speaker 3: Rocks and sand and dirt they don't do that. Their
Speaker 3: reflection spectra are usually smooth slopes, they don't have sharp edges.
Speaker 3: If you see that cliff, it's one of the strongest
Speaker 3: signs of widespread complex life you could ever hope for.
Speaker 2: But and I'm sensing the catch here, the thing the
Speaker 2: white paper is worried about. You can only see that
Speaker 2: cliff if your camera can see into the infrared.
Speaker 3: There's the catch. If the budget committee says, hey, those
Speaker 3: near infrared sensors are too complex, too expensive, let's just
Speaker 3: stick to the visible light our eyes can see. Then
Speaker 3: you completely miss the red edge.
Speaker 2: The cliff is invisible to you.
Speaker 3: It's invisible. You could be looking at a planet covered
Speaker 3: in the Amazon rainforest and it would just look like
Speaker 3: a dark, unremarkable smudge. You miss the smoking gun.
Speaker 2: So that's argument number one for the expensive model. We
Speaker 2: need infrared to see earth like life today. But the
Speaker 2: paper goes deeper, doesn't it, because looking for modern Earth
Speaker 2: isn't enough.
Speaker 3: Not even close. I mean, this is where it gets
Speaker 3: really mind bending for me. We're so biased towards green chlorophyll,
Speaker 3: but chlorophyll is in the grand scheme of things, a
Speaker 3: fairly recent invention for a huge chunk of our planet's history.
Speaker 3: The world wasn't green, it was purple. It was purple.
Speaker 2: The purple Earth hypothesis. I love this, So take us back.
Speaker 2: What's going on purple Earth.
Speaker 3: We're talking maybe three billion, two point five billion years ago.
Speaker 3: The most advanced life forms on the planet were these
Speaker 3: single celled organisms purple and oxygenic phototrufs.
Speaker 2: Okay, that's a mouseful it is.
Speaker 3: Let's just call them purple bacteria. The key thing is
Speaker 3: they didn't use chlorophyll for photosynthesis. They used a different
Speaker 3: kind of pigment called retinal.
Speaker 2: Retinal wait as in this stuff in our retinas in
Speaker 2: our eyes, very.
Speaker 3: Very similar chemical structure, the same pigments your eyes used
Speaker 3: to detect light. These ancient bacteria used to harvest energy
Speaker 3: from the sun, and they work differently from chlorophyll. Chlorophyll
Speaker 3: absorbs red and blue, reflects green. Retinal is basically the opposite.
Speaker 3: It's most efficient at absorbing green and yellow light, which
Speaker 3: by the way, is the peak of the Sun's energy output.
Speaker 2: So it's absorbing the most powerful part of the sunlight.
Speaker 2: And if it absorbs green.
Speaker 3: Flex the other parts. It reflects red and blue light.
Speaker 2: And if you mix red and blue paint you get you.
Speaker 3: Get purple, a deep, rich purple.
Speaker 2: So for a billion years, maybe more, any continents or
Speaker 2: shallow coastal areas on Earth would have been covered in
Speaker 2: these vast purple mats of bacteria.
Speaker 3: And this isn't just a theory. We still have them.
Speaker 3: If you go to super salty places like the Great
Speaker 3: Salt Lake or certain salt flats, you can see these
Speaker 3: organisms called halo bacteria. They turn the water that shocking
Speaker 3: brilliant pink or purple color.
Speaker 2: So we can see what ancient Earth looked like today
Speaker 2: we can.
Speaker 3: And here's the number from the paper that just flings me.
Speaker 3: This purple Earth phase might have lasted for nearly one
Speaker 3: point five billion years.
Speaker 2: That's staggering. That's more than twice as long as complex
Speaker 2: animals have even existed.
Speaker 3: Exactly, for a huge percentage of the time that Earth
Speaker 3: has been alive, it was a purple planet. So now
Speaker 3: apply that to the telescope problem.
Speaker 2: Okay, So if HWO is scanning the galaxy and it
Speaker 2: finds a planet that happens to be in its own
Speaker 2: own purple phase, right now.
Speaker 3: What do we see.
Speaker 2: Well, if we don't have the right sensors, we see nothing.
Speaker 3: We see nothing. These purple bacteria, they're retinal pigments. They
Speaker 3: absorb light well into the infrared, so their spectral signature,
Speaker 3: their edge is different from chlorophylls. If we build a
Speaker 3: telescope that is only looking for the red edge of
Speaker 3: modern plants.
Speaker 2: We're wearing the wrong color glasses.
Speaker 3: You're wearing the wrong glasses. You would look at a
Speaker 3: world that is absolutely teeming with life, a thriving global biosphere,
Speaker 3: and your multi billion dollar instrument would tell you it's
Speaker 3: a dead rock.
Speaker 2: That is the ultimate nightmare scenario. We spend twenty years
Speaker 2: building this thing pointed at a second Earth and just
Speaker 2: completely fail to recognize it.
Speaker 3: That's the argument. The Living World's Working Group is basically screaming,
Speaker 3: you cannot design this machine just to find us today.
Speaker 3: You have to design it to find who we were yesterday.
Speaker 3: Because statistically, for any given planet, it might be more
Speaker 3: likely to be in its purple phase than its green phase.
Speaker 2: Okay, so we've got purple Earth. But the story doesn't
Speaker 2: just jump from purple to the green forest we see today.
Speaker 2: There was an intermediate step in the outline.
Speaker 3: There was a middle chapter, the green Ocean hypothesis.
Speaker 2: Where the oceans themselves turned green.
Speaker 3: Yes, this is a fascinating period geologically and biologically. We're
Speaker 3: talking about the rchae and eon. So maybe between four
Speaker 3: and two point five billion years ago, the world was different.
Speaker 3: The atmosphere had no oxygen.
Speaker 2: So what made the water green? Was it some kind
Speaker 2: of early algae?
Speaker 3: No? Not, At first, it was the rock the planet's geology.
Speaker 3: The oceans were full of dissolved iron that was being
Speaker 3: pumped out of hydrothermal events. On the seafloor, specifically.
Speaker 2: Ferric iron, and that colors the water.
Speaker 3: It does. Ferrisc iron in a solution is really good
Speaker 3: at absorbing light at the blue and red ends of
Speaker 3: the spectrum, but it doesn't absorb green light very well.
Speaker 2: So it reflects the green the ocean itself. Just the
Speaker 2: water and iron would have looked green, that.
Speaker 3: Kind of murky olive green probably, But then life adapts.
Speaker 3: Evolution is always an opportunist. You have these early cyanobacteria
Speaker 3: floating in the water. They need sunlight, but the water
Speaker 3: they're living in is filtering out all the good red
Speaker 3: and blue light, so.
Speaker 2: The only light that's making it down to them is
Speaker 2: the green light that the iron isn't absorbing the leftovers.
Speaker 3: So what do they do? They evolve a new tool.
Speaker 3: They develop special accessory pigments called phycobilins that are perfectly
Speaker 3: tuned to capture and use green light for photosynthesis.
Speaker 2: It's like they're tuning their antenna to the only radio
Speaker 2: station that's.
Speaker 3: Broadcasting perfect analogy, and so you get this layered effect.
Speaker 3: You have a geological green signal from the iron and
Speaker 3: then a biological green signal from the bacteria living in it.
Speaker 2: Now from the telescope's point of view, that's got to
Speaker 2: be confusing.
Speaker 3: It's extremely confusing because if you just look at the
Speaker 3: overall color, a bionet with a green ocean full of
Speaker 3: cyanobacteria looks very, very similar to a planet with continents
Speaker 3: covered in green forests.
Speaker 2: So if we saw that, would it even matter? I mean,
Speaker 2: green is green? Life is life? We pop the champagne, right,
Speaker 2: I mean yes and no.
Speaker 3: On the one hand, any row bust green signal is
Speaker 3: a huge deal, But scientifically we'd want to know what
Speaker 3: we're looking at. Is this a primitive oxygen poor world
Speaker 3: with simple bacteria or.
Speaker 2: Is it a mature, oxygen rich world with complex plants.
Speaker 3: Those are two fundamentally different stages of planetary evolution. Telling
Speaker 3: them apart requires incredibly high spectral resolution. You need to
Speaker 3: be able to see the subtle little bumps and wiggles
Speaker 3: in the spectrum that differentiate a phycobilin pigment from a
Speaker 3: chlorophyll pigment.
Speaker 2: So again it comes back to the quality of the instrument.
Speaker 2: Don't give us a blurry, low res camera exactly.
Speaker 3: But it gets even more complicated because sometimes a color
Speaker 3: that looks like life isn't life at all. Sometimes it's
Speaker 3: just a rock trying to fool you.
Speaker 2: This is the part that gives me anxiety. The mimics,
Speaker 2: the false positives.
Speaker 3: This is the core of the engineering argument in the paper.
Speaker 3: It's about being sure. We are so desperate to find life,
Speaker 3: there's a huge risk of confirmation bias. We want to believe.
Speaker 3: The universe, however, is full of minerals that can look
Speaker 3: an awful lot like biology.
Speaker 2: So let's go through the list of suspects. What's mimic
Speaker 2: number one?
Speaker 3: The most obvious one is iron oxide rust Mars. Mars
Speaker 3: is the poster child. It's the red planet because it's
Speaker 3: covered in rust. Spectrally, rust creates what's called a red slope.
Speaker 3: It just reflects more and more light as you go
Speaker 3: from green to red to infrared.
Speaker 2: And if you have a blurry instrument, a gentle slope
Speaker 2: can look a lot like a sharp edge.
Speaker 3: They can blur together. Think about looking at a ramp
Speaker 3: versus a single step from really far away. If your
Speaker 3: vision is bad, they can look the same. You could
Speaker 3: absolutely mistake a dead, rusty desert planet for a world
Speaker 3: covered in vegetation.
Speaker 2: So how do you tell them apart.
Speaker 3: You need high resolution. You need to be able to
Speaker 3: see the sharpness of the feature. Biology creates sharp, well
Speaker 3: defined edges. Geology is usually smoother, more sloped. You need
Speaker 3: an instrument that can tell the difference.
Speaker 2: Okay, so rust is a big one, but the paper
Speaker 2: mentioned another mineral that was much more exotic. Cinebar.
Speaker 3: Cinebar. Yeah, mercury sulfide. It's this brilliant red mineral, and
Speaker 3: it's mercury.
Speaker 2: It's incredibly toxic.
Speaker 3: You would not want to land on a planet made
Speaker 3: of cinebar. But here's the universe playing a cruel joke
Speaker 3: on us. Cinebar has a spectral feature. It has a
Speaker 3: very strong, very sharp reflective edge.
Speaker 2: It's like plants.
Speaker 3: Doo, just like plants, but there's one tiny critical difference.
Speaker 3: The vegetation red edge happens at a wavelength of about
Speaker 3: seven hundred animeters. Okay, the cinnabar edge happens at about
Speaker 3: six hundred animeters.
Speaker 2: That's one hundred animeters. That sounds like almost nothing.
Speaker 3: It is almost nothing. And if your telescope has low
Speaker 3: spectral resolution, if your pixels are too fat, then six
Speaker 3: hundred nanimeters and seven hundred animeters can fall into the
Speaker 3: same data bin, they blur together into one signal.
Speaker 2: So imagine the press conference. NASA gets up and says,
Speaker 2: we found it a planet with a clear biological edge.
Speaker 2: It's covered in red forests.
Speaker 3: And then ten years later a better instrument goes up
Speaker 3: and we realize, oh, whoops, it's actually a giant poison
Speaker 3: us mercury rock.
Speaker 2: That would be devastating.
Speaker 3: That is the nightmare. That is why they are fighting
Speaker 3: for this high resolution. They're saying, we have to be
Speaker 3: able to tell the difference between six hundred and seven
Speaker 3: hundred nanimeters with absolute certainty. We need to be able
Speaker 3: to distinguish a tree from a toxic rock.
Speaker 2: Wow. Okay, and there was one more mimic, right, sulfur
Speaker 2: elemental sulfur.
Speaker 3: Yeah, it has its own edge, but it's down around
Speaker 3: four hundred and fifty to five hundred nanometers. It's a
Speaker 3: little easier to spot because it's further away from the
Speaker 3: vegetation signal, but the principle is the same. A planet
Speaker 3: could have a weird mix of minerals, maybe some sulfur
Speaker 3: and some cinnabar.
Speaker 2: And with a low res instrument, that combination of signals
Speaker 2: could mash together into something that looks convincingly and incorrectly biological.
Speaker 3: You got it. It's not that the universe is intentionally
Speaker 3: trying to trick us. It's just that chemistry is complex,
Speaker 3: and biology is just a very specific, very organized form
Speaker 3: of mistry. To find it, you need tools that are
Speaker 3: precise enough to measure that specific or organization.
Speaker 2: So this all brings us back to the present day,
Speaker 2: to the horse trading. We have this paper the scientific argument,
Speaker 2: but it's really it's a negotiating tool.
Speaker 3: It's absolutely a negotiating tool. The Living World's Working Group
Speaker 3: is laying out its case for the budget committees at
Speaker 3: NASA and in Congress.
Speaker 2: And the case is basically, if you cut our budget
Speaker 2: and force us to buy the cheap camera, we.
Speaker 3: Will confuse mercury for forests, We will miss entire purple biospheres.
Speaker 3: The mission you're paying for will not be the mission
Speaker 3: you get.
Speaker 2: So what's the wish list summed up?
Speaker 3: It's three things. One high signal to noise so we
Speaker 3: can actually see the faint light from the surface. Two
Speaker 3: wide spectral range from visible light through near infrared, so
Speaker 3: we can see both the red edge and the signatures
Speaker 3: of purple earths. And three high spectral resolutions, so we
Speaker 3: can tell the difference between a real biological edge and
Speaker 3: a geological mimic like cinebar.
Speaker 2: And what's the reality, what's likely to happen. The sources
Speaker 2: mentioned recent cuts to other big NASA programs.
Speaker 3: The reality is that the budget is ex extremely tight.
Speaker 3: It's very unlikely they'll get everything on their wish lists.
Speaker 3: They are going to be compromises.
Speaker 2: But the compromise here feels so much more significant than
Speaker 2: you know, getting a slightly smaller hard drive.
Speaker 3: It is a compromise here fundamentally changes the nature of
Speaker 3: the mission. It takes you from a mission of discovery
Speaker 3: and confirmation to a mission of discovery and ambiguity.
Speaker 2: And nobody wants to spend twenty years and ten billion
Speaker 2: dollars just to get a maybe.
Speaker 3: Exactly, to spend all that time and effort to point
Speaker 3: to a pale, purple dot and say, well, that might
Speaker 3: be life, but it also might be a rock, that
Speaker 3: would be an excruciating result. The scientists are arguing it's
Speaker 3: better to build the yes or No machine, even if
Speaker 3: it costs more.
Speaker 2: Upfront, because we might only get one shot at this.
Speaker 3: We will only get one shot at this in our lifetimes.
Speaker 3: This is the flagship observatory for the next generation. We
Speaker 3: are building the eyes that our children and grandchildren will
Speaker 3: use to explore the galaxy.
Speaker 2: And if we build them with cataracts on day one
Speaker 2: to save a bit of money, they're going to be
Speaker 2: the one squinting at the blurry data.
Speaker 3: That's the stakes. This paper is a plea to look
Speaker 3: at the long game.
Speaker 2: So we've gone all the way from the pale blue
Speaker 2: dot to purple bacteria, green oceans, and toxic mimics. It's
Speaker 2: a much more complicated picture of what life might look.
Speaker 3: Like it really is. It shows that to find life
Speaker 3: out there, we first have to really really understand the
Speaker 3: deep history of life right here.
Speaker 2: We have to remember our own purple past.
Speaker 3: Mm hmm, and we have to be open to the
Speaker 3: idea that pale blue is just one outfit in a
Speaker 3: very large cosmic wardrobe.
Speaker 2: So as we wrap up, I want to leave everyone
Speaker 2: listening with a final thought on this. We always talk
Speaker 2: about the cost of these huge projects, billions of dollars
Speaker 2: for a telescope, A lot of money, it is, but
Speaker 2: think about the cost of not doing it right. Imagine
Speaker 2: we build the cheaper version, we scan a thousand worlds
Speaker 2: and we find nothing but ambiguous smudges, we might conclude
Speaker 2: we're alone.
Speaker 3: Right, we'd get a null result and just assume there's
Speaker 3: nothing there.
Speaker 2: But what if we weren't alone. What if the galaxy
Speaker 2: is filled with purple worlds and we just didn't buy
Speaker 2: the right pair of glasses to see them. What's the
Speaker 2: higher cost, the cost of the telescope or the cost
Speaker 2: of staying alone in the universe when we didn't have
Speaker 2: to be.
Speaker 3: Yeah, that's the question.
Speaker 2: To look right at a living planet and see a
Speaker 2: dead rock because of a budget decision made decades earlier.
Speaker 2: I mean, that feels like a tragedy on a galactic.
Speaker 3: Scale, the ultimate missed connection.
Speaker 2: Here's hoping the living world's working group wins their fight.
Speaker 2: Thanks so much for walking us through.
Speaker 3: All this My pleasure. Keep looking up and maybe look
Speaker 3: for purple sass s