# NASA’s Roman Telescope Is About to Change How We See the Universe

An episode of [Bedtime Astronomy](https://invisiblenetwork.ai/podcast/1736397134), 30 Aug 2026, 41 min.

Audio: https://dts.podtrac.com/redirect.mp3/api.spreaker.com/download/episode/74754665/ronantelescopep.mp3

NASA’s Nancy Grace Roman Space Telescope is about to open a new window on the universe. With a field of view roughly 100 times larger than Hubble’s, Roman will survey enormous regions of space while investigating dark energy, dark matter, galaxy evolution, and thousands of exoplanets. Its experimental coronagraph will also test technology for directly imaging distant worlds. Working alongside Hubble and Webb, Roman could uncover unexpected clues about how the cosmos evolved—and potentially challenge our understanding of the universe. Thank you for listening to Bedtime Astronomy — your guide to the cosmos. New episodes on space exploration, NASA missions & the latest astronomy breakthroughs. This episode includes AI-generated content.

## Transcript

[0:03] Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
[0:07] Speaker 1: with our soothing Bedtime Astronomy podcast. Each episode offers a
[0:12] Speaker 1: gentle journey through the stars, planets, and beyond, perfect for
[0:16] Speaker 1: unwinding after a long day. Let's travel through the mysteries
[0:20] Speaker 1: of the universe as you drift off into a peaceful
[0:22] Speaker 1: slumber under the night sky.
[0:26] Speaker 2: What if I told you that in order to finally
[0:29] Speaker 2: see the invisible forces tearing our universe apart, We actually
[0:32] Speaker 2: had to build a mirror shaped by thousands of microscopic motors.
[0:37] Speaker 1: Oh, yeah.
[0:37] Speaker 2: Like each one making adjustments smaller than the width of
[0:40] Speaker 2: a strand of human DNA. And that today, that exact
[0:44] Speaker 2: piece of machinery is sitting on a launch pad surrounded
[0:47] Speaker 2: by venting liquid oxygen, just waiting to be blasted a
[0:50] Speaker 2: million miles away from Earth.
[0:52] Speaker 3: It's honestly surreal to think about.
[0:54] Speaker 2: It really is. Today is Sunday, August 30, 2026, down
[0:59] Speaker 2: at Launch Complex 39A at the Kennedy Space Center in Florida.
[1:02] Speaker 3: Right, the exact same concrete pad where Apollo 11 started
[1:05] Speaker 3: its journey to the moon.
[1:06] Speaker 2: Yeah, exactly. So SpaceX Falcon Heavy is fueled, it's counting down,
[1:10] Speaker 2: and humanity is basically holding its breath right now.
[1:12] Speaker 3: The atmosphere on the ground there is just electric. I mean,
[1:15] Speaker 3: at 76 a.m. Eastern, the Launch Readiness Review Board officially
[1:19] Speaker 3: gave the final green light. We are literally minutes away
[1:22] Speaker 3: from NASA lighting those engines.
[1:24] Speaker 2: Which is just wild.
[1:25] Speaker 3: Right. And what is tucked inside the payload fairing of
[1:28] Speaker 3: that rocket, it's not just another... piece of hardware. We
[1:33] Speaker 3: are launching a deeply sophisticated tool designed to answer, I'd argue,
[1:37] Speaker 3: the most terrifying and magnificent questions in modern physics.
[1:41] Speaker 2: Look at what the universe is actually made of.
[1:43] Speaker 3: Exactly. What it's made of and, you know, are we
[1:45] Speaker 3: alone in it?
[1:46] Speaker 2: Which is the entire reason you are here with us today.
[1:48] Speaker 2: We are dedicating this conversation to exploring exactly what is
[1:53] Speaker 2: about to be placed into orbit and why it's going
[1:56] Speaker 2: to fundamentally shatter our understanding of reality.
[1:58] Speaker 3: It really will.
[1:59] Speaker 2: And to understand the gravity, what's happening this morning, we
[2:03] Speaker 2: need to look at the name painted on the side
[2:05] Speaker 2: of that observatory, the Nancy Grace Roman Space Telescope.
[2:08] Speaker 3: Yeah, and naming this observatory after her is just a
[2:11] Speaker 3: profound piece of poetic justice. Nancy Grace Roman was NASA's
[2:15] Speaker 3: first chief astronomer, taking on that executive role back in 1959.
[2:19] Speaker 2: Which is crazy because NASA was barely a year old
[2:22] Speaker 2: at that point.
[2:22] Speaker 3: Right, and think about the culture of aerospace in 1959.
[2:25] Speaker 2: Oh, I mean, the space race was purely about Putting
[2:29] Speaker 2: men in metal cans and beating the Soviets.
[2:31] Speaker 3: Spot on. Astronomy wasn't even an afterthought. It was barely
[2:34] Speaker 3: on the radar. She was stepping into this completely male
[2:38] Speaker 3: dominated engineering first culture and trying to convince them to,
[2:42] Speaker 3: you know, look at the stars.
[2:43] Speaker 2: We had to fight tooth and nail for every single dollar.
[2:47] Speaker 3: She really did. Every dollar, every ounce of institutional support.
[2:51] Speaker 3: She's famously known as the mother of the Hubble Space
[2:53] Speaker 3: Telescope because she was the visionary who tirelessly advocated for
[2:57] Speaker 3: putting a telescope in space.
[2:58] Speaker 2: Because ground-based astronomers were super skeptical at the time.
[3:02] Speaker 3: Oh, entirely. They thought space telescopes were way too expensive and, frankly,
[3:06] Speaker 3: just too risky. Roman had to travel the country, organizing
[3:10] Speaker 3: the astronomical community, basically arguing that looking through the Earth's
[3:14] Speaker 3: churning atmosphere was like looking through a warped, boiling windowpane.
[3:17] Speaker 2: Wow, yeah.
[3:18] Speaker 3: We needed to get above it. So she laid the
[3:20] Speaker 3: foundational groundwork that eventually led to Hubble.
[3:23] Speaker 2: And Hubble completely changed human culture. I mean, it gave
[3:26] Speaker 2: us the pillars of creation, the Hubble Deep Field. It
[3:29] Speaker 2: gave us a universe that felt tangibly real.
[3:32] Speaker 3: It absolutely did.
[3:33] Speaker 2: And now, decades after she laid that foundation, an observatory
[3:38] Speaker 2: bearing her own name is sitting on a launch pad.
[3:42] Speaker 2: preparing to kick off a completely new era of observation.
[3:46] Speaker 3: Her legacy is coming full circle in just the most
[3:49] Speaker 3: spectacular way possible.
[3:50] Speaker 2: So to understand why Roman is going to be so revolutionary,
[3:54] Speaker 2: we need to look at the physical architecture of the machine, right?
[3:57] Speaker 2: Like compared to what we've relied on for the past
[3:59] Speaker 2: three decades.
[4:00] Speaker 3: Yeah, let's look at the hardware.
[4:01] Speaker 2: Let's start with the primary mirror, the big reflective dish
[4:04] Speaker 2: that gathers all the ancient light from the cosmos. The
[4:07] Speaker 2: mirror on Roman is 2.4 meters in diameter.
[4:10] Speaker 1: Yeah.
[4:11] Speaker 2: But wait, isn't that the exact same size as Hubble's
[4:13] Speaker 2: primary mirror?
[4:14] Speaker 3: It is, yeah. Exactly the same size.
[4:16] Speaker 2: So why are we sending up a mirror the same
[4:17] Speaker 2: size as the one we launched in 1990? That feels like,
[4:20] Speaker 2: I don't know, we're just repeating ourselves.
[4:21] Speaker 3: I get why you'd think that. On paper, it looks
[4:24] Speaker 3: like a repeat. I mean, a 2.4 meter mirror gathers
[4:28] Speaker 3: the same amount of light as a 2.4 meter mirror,
[4:31] Speaker 3: whether it was built in 1990 or 2026. Right. But
[4:34] Speaker 3: the true leap forward isn't the size of the glass.
[4:37] Speaker 3: It is the focal plane. It is the field of view.
[4:40] Speaker 3: Roman's primary camera sees an area of the sky that
[4:43] Speaker 3: is at least 100 times larger than Hubble's.
[4:46] Speaker 2: 100 times larger.
[4:48] Speaker 3: At least. And it does this while maintaining the exact
[4:51] Speaker 3: same razor-sharp angular resolution and infrared sensitivity.
[4:56] Speaker 2: Okay, let me try to visualize this. Imagine you are
[4:59] Speaker 2: standing at the edge of the Grand Canyon, trying to
[5:01] Speaker 2: take in the vast, sweeping landscape. But you're forced to
[5:04] Speaker 2: look at it through a drinking straw.
[5:06] Speaker 3: Right, that's Hubble.
[5:07] Speaker 2: Yeah, that is Hubble. You can see the striations on
[5:09] Speaker 2: a single pebble, the bottom of the canyon perfectly. It's
[5:12] Speaker 2: stunningly clear. But you have to move the straw millimeter
[5:15] Speaker 2: by millimeter to see the whole canyon.
[5:17] Speaker 3: Exactly.
[5:18] Speaker 2: So what Roman does is take away the drinking straw
[5:20] Speaker 2: and open up a massive floor-to-ceiling bay window. But somehow,
[5:24] Speaker 2: by some absolute miracle of engineering, it maintains that microscopic
[5:30] Speaker 2: pebble-level clarity across the entire expanse of the window.
[5:34] Speaker 3: That is a perfect analogy. And the instrument making that
[5:37] Speaker 3: bay window possible is called the Wide Field Instrument, or
[5:40] Speaker 3: the WFI.
[5:41] Speaker 2: WFI, got it.
[5:42] Speaker 3: This is Romans' primary scientific engine. It was a wide
[5:46] Speaker 3: field camera and a slitless spectrometer that observes visible to
[5:51] Speaker 3: near infrared light.
[5:53] Speaker 2: Okay, there's a lot there.
[5:54] Speaker 3: I know. Let me break it down. The heart of
[5:56] Speaker 3: this instrument consists of 18 separate infrared detector arrays.
[6:00] Speaker 2: OK, but break down what those arrays actually do, because
[6:02] Speaker 2: infrared detector array sounds like, you know, standard NASA jargon.
[6:06] Speaker 2: What are we actually looking at?
[6:07] Speaker 3: Right. So these are specialized microchips. Specifically, they're made of
[6:10] Speaker 3: a material called mercury cadmium telluride.
[6:12] Speaker 2: Catchy name.
[6:13] Speaker 3: Very. But their sole job is to wait for ancient photons.
[6:17] Speaker 3: So particles of light that have been traveling across the
[6:19] Speaker 3: vacuum of space for billions of years to strike their surface.
[6:23] Speaker 3: When a photon hits the chip, It knocks an electron loose,
[6:27] Speaker 3: translating a multi-billion-year-old physical particle into a tiny electrical signal.
[6:32] Speaker 2: Wow.
[6:33] Speaker 3: And across those 18 arrays, Roman captures roughly 300 million
[6:37] Speaker 3: pixels per single image.
[6:39] Speaker 2: 300 million pixels. That's, I mean, if you hold your
[6:43] Speaker 2: thumb up to the night sky at arm's length, the
[6:44] Speaker 2: full moon is about half the width of your thumb, right?
[6:46] Speaker 3: Roughly, yeah.
[6:47] Speaker 2: And Hubble's view is, what, a tiny fraction of a
[6:50] Speaker 2: grain of sand sitting on your thumbnail?
[6:52] Speaker 3: Exactly.
[6:53] Speaker 2: But Roman captures the entire moon. and a huge swath
[6:56] Speaker 2: of the sky around it in one single shot with
[6:59] Speaker 2: Hubble-level detail.
[7:00] Speaker 3: You got it. Because of that massive field of view,
[7:03] Speaker 3: NASA estimates Roman will be able to survey the sky
[7:06] Speaker 3: up to 1,000 times faster than Hubble.
[7:09] Speaker 2: A thousand times faster. Yeah.
[7:10] Speaker 3: In its primary five-year mission, Roman is expected to image
[7:14] Speaker 3: 50 times more of the sky than Hubble managed in
[7:17] Speaker 3: its entire 30-year lifespan.
[7:19] Speaker 2: That is just insane to think about. We are moving
[7:21] Speaker 2: from Like intimate portrait photography to panoramic mapping on a
[7:25] Speaker 2: cosmic scale.
[7:26] Speaker 3: That's exactly what's happening.
[7:28] Speaker 2: You mentioned earlier that the WFI is also a slitless spectrometer.
[7:32] Speaker 2: I need an ELI-5 on that because a spectrometer usually
[7:35] Speaker 2: involves shining light through a tiny slit to break it
[7:39] Speaker 2: down into a rainbow, right? Like a prism.
[7:41] Speaker 3: Yes, exactly like a prism.
[7:43] Speaker 2: So how do you do that without a slit? And
[7:45] Speaker 2: why would you even want to?
[7:46] Speaker 3: Okay, so a traditional spectrometer uses a tiny slit to
[7:49] Speaker 3: isolate the light of one single star or galaxy. It
[7:52] Speaker 3: blocks out everything else, takes that one isolated beam of light,
[7:56] Speaker 3: and passes it through a grating, which is essentially a
[7:58] Speaker 3: high-tech prism, to spread the light out into a spectrum.
[8:02] Speaker 2: Like a chemical barcode.
[8:03] Speaker 3: Perfect way to describe it. That barcode tells you what
[8:06] Speaker 3: the star is made of, how hot it is, and
[8:08] Speaker 3: how fast it's moving away from us.
[8:10] Speaker 2: But Roman doesn't have a slit.
[8:11] Speaker 1: Right.
[8:12] Speaker 3: Roman takes that massive bay window you mentioned, captures the
[8:15] Speaker 3: light from millions of galaxies simultaneously, and passes all of
[8:19] Speaker 3: it through a prism at the exact same time.
[8:21] Speaker 2: Wait, won't that just be a giant mess?
[8:23] Speaker 3: It creates millions of overlapping, messy chemical barcodes in a
[8:27] Speaker 3: single image. It sounds totally chaotic, and honestly.
[8:30] Speaker 2: It is. How do they even read that?
[8:32] Speaker 3: It requires incredibly complex software to untangle the overlapping spectra.
[8:37] Speaker 3: But doing it this way allows us to gather the
[8:39] Speaker 3: chemical and kinetic data of millions of objects at once,
[8:43] Speaker 3: rather than measuring them one painstaking star at a time.
[8:46] Speaker 2: Oh, wow. Okay, that makes sense. And all of this
[8:49] Speaker 2: is being done in the infrared spectrum. Why infrared? Why
[8:52] Speaker 2: not just visible light, like what our eyes see?
[8:55] Speaker 3: Because the universe is expanding. Right. When light leaves a
[8:58] Speaker 3: distant galaxy, it might start as visible blue light. But
[9:03] Speaker 3: as it travels toward us, the actual fabric of space
[9:06] Speaker 3: is stretching.
[9:07] Speaker 2: Stretching the light with it.
[9:08] Speaker 3: Exactly. As space stretches, the light wave stretches right along
[9:12] Speaker 3: with it. By the time it reaches Earth billions of
[9:15] Speaker 3: years later, that blue light wave has been stretched so
[9:18] Speaker 3: far that it has fallen off the visible spectrum entirely
[9:21] Speaker 3: and become infrared light.
[9:22] Speaker 2: Which is called redshift, right?
[9:24] Speaker 3: You got it, redshift. So if you want to see
[9:26] Speaker 3: the ancient distant universe, you have to look in the infrared.
[9:29] Speaker 2: Which introduces a massive engineering headache, doesn't it? Because infrared
[9:32] Speaker 2: light is essentially heat.
[9:34] Speaker 3: Yes, it is.
[9:35] Speaker 2: So if you build a telescope to look for the
[9:37] Speaker 2: faintest traces of heat from the very edge of the universe,
[9:41] Speaker 2: the telescope itself cannot be warm.
[9:43] Speaker 3: It has to be freezing. If the detector chips or
[9:46] Speaker 3: the mirror are even slightly warm, their own thermal radiation
[9:49] Speaker 3: will completely blind the sensors.
[9:51] Speaker 2: Like trying to see the stars during a sunny day.
[9:53] Speaker 3: Exactly. So Roman has an active cooling system and a
[9:57] Speaker 3: massive sun shield to keep its detectors chilling at roughly
[10:01] Speaker 3: minus 288 degrees Fahrenheit.
[10:03] Speaker 2: Minus 288. It's just an astonishing piece of machinery. But
[10:07] Speaker 2: having a camera that can map the universe thousands of
[10:09] Speaker 2: times faster isn't just about taking sweeping photographs.
[10:13] Speaker 3: No, not at all.
[10:13] Speaker 2: It's about having a lens wide enough. to finally measure
[10:17] Speaker 2: the invisible forces that are literally tearing our universe apart.
[10:19] Speaker 3: Right, because we're facing a fundamental cosmic crisis.
[10:23] Speaker 2: A crisis.
[10:24] Speaker 3: Oh, absolutely. Let's go back to Edwin Hubble in the 1920s.
[10:27] Speaker 3: He was up at the Mount Wilson Observatory looking at
[10:29] Speaker 3: cepheid variable stars. These are stars that pulse in brightness
[10:33] Speaker 3: at a regular rate. So, building on the brilliant foundational
[10:37] Speaker 3: math of Henrietta Swan Leavitt, Hubble used these pulsing stars
[10:41] Speaker 3: to prove two major things. First... That the Milky Way
[10:45] Speaker 3: is not the only galaxy in the universe.
[10:47] Speaker 2: Which was huge at the time.
[10:49] Speaker 3: Massive. And second, that all the other galaxies are moving
[10:52] Speaker 3: away from us. The universe is expanding.
[10:55] Speaker 2: And for decades, the assumption was that this expansion must
[10:58] Speaker 2: be slowing down, right? Because of gravity.
[11:00] Speaker 3: That was the logical assumption, yeah.
[11:02] Speaker 2: Like, if you throw an apple into the air, the
[11:03] Speaker 2: initial explosion of energy pushes it up, but the gravity
[11:07] Speaker 2: of the Earth pulls it back, slowing it down.
[11:09] Speaker 3: Right.
[11:10] Speaker 2: So all the mass in the universe, all the stars,
[11:13] Speaker 2: black holes and dark matter should be acting like a
[11:15] Speaker 2: gravitational anchor, slowing the expansion of the universe.
[11:19] Speaker 3: That was the consensus until the late 1990s. Astronomers were
[11:22] Speaker 3: trying to measure exactly how much the universe was slowing down.
[11:26] Speaker 2: And what did they find?
[11:27] Speaker 3: Instead, they discovered something that completely broke our understanding of physics.
[11:31] Speaker 3: The expansion of the universe isn't slowing down under the
[11:34] Speaker 3: weight of its own gravity. It is accelerating.
[11:37] Speaker 2: So the apple isn't slowing down. It's rocketing upward faster
[11:40] Speaker 2: and faster every second.
[11:42] Speaker 1: Yes.
[11:43] Speaker 3: Galaxies are flying away from each other at an accelerating rate.
[11:46] Speaker 3: The driver behind this acceleration is this massive phantom phenomenon
[11:51] Speaker 3: that scientists slapped a placeholder name onto. Dark energy.
[11:56] Speaker 2: We call it dark energy, but that label is really
[11:59] Speaker 2: just a mask for our ignorance, isn't it? We don't
[12:01] Speaker 2: actually know what it is.
[12:02] Speaker 3: We have no idea. We can't see it directly. Dark
[12:05] Speaker 3: energy can only be inferred by looking at the behavior
[12:08] Speaker 3: of the universe on the most massive scales imaginable.
[12:11] Speaker 2: Wow.
[12:12] Speaker 3: It makes up roughly 68% of the entire universe, and
[12:15] Speaker 3: yet we have no idea if it's a new fundamental force,
[12:18] Speaker 3: a property of empty space itself, or something else entirely.
[12:22] Speaker 2: Which is why Roman's mission is so critical. Exactly. Because
[12:24] Speaker 2: Roman has that massive field of view. It can see
[12:27] Speaker 2: the whole board, not just a single chess piece. So
[12:29] Speaker 2: what specific question is Roman trying to answer about dark energy?
[12:33] Speaker 3: Roman is designed to test if dark energy has been
[12:36] Speaker 3: a constant, steady force pushing outward throughout the entire 13.8
[12:41] Speaker 3: billion year history of the universe, or if it is
[12:44] Speaker 3: an evolving force that changes its strength over time.
[12:47] Speaker 2: OK, but what happens if Roman opens its bay window,
[12:52] Speaker 2: crunches the data, and we find out dark energy is changing?
[12:55] Speaker 2: What are the actual stakes for the physics community here?
[12:59] Speaker 3: The implications are profoundly disruptive.
[13:02] Speaker 2: Like how disruptive?
[13:03] Speaker 3: If dark energy is evolving, it means our foundational understanding
[13:07] Speaker 3: of physics is incomplete. Albert Einstein's theory of general relativity,
[13:11] Speaker 3: the theory of gravity that has survived every test we've
[13:14] Speaker 3: thrown at it for a century, might need a massive
[13:17] Speaker 3: ground-up overhaul on a cosmological scale.
[13:20] Speaker 2: No kidding.
[13:21] Speaker 3: No, I mean it. We might have to rewrite the
[13:23] Speaker 3: most basic textbooks on how the universe operates. Einstein might
[13:26] Speaker 3: have been wrong about how gravity works over distances of
[13:29] Speaker 3: billions of light years.
[13:30] Speaker 2: That is, we are launching a telescope that might essentially
[13:32] Speaker 2: prove Einstein needed to carry one somewhere in his map.
[13:35] Speaker 3: That's a great way to put it, yeah.
[13:36] Speaker 2: But how exactly does Roman measure something it can even see?
[13:40] Speaker 3: It uses several complementary techniques, but one of the most
[13:43] Speaker 3: powerful is hunting for a specific type of exploding star
[13:47] Speaker 3: known as a type Ia supernova. Astrophysicists call them standard candles.
[13:52] Speaker 2: Okay, I want to push back on this concept of
[13:53] Speaker 2: the standard candy because I've always found it a bit suspicious.
[13:56] Speaker 3: Fair enough. Go ahead.
[13:57] Speaker 2: You're telling me we're going to rewrite Einstein's laws of
[13:59] Speaker 2: physics based on the perceived brightness of exploding stars. How
[14:04] Speaker 2: can we possibly know that every single type ES supernova
[14:08] Speaker 2: in the universe explodes with the exact same brightness?
[14:12] Speaker 3: It's a great question, and it comes down to the
[14:14] Speaker 3: precise quantum mechanics of how they explode. A type ES
[14:18] Speaker 3: supernova happens in a binary star system called Where a
[14:21] Speaker 3: dense dead star called a white dwarf is orbiting a
[14:24] Speaker 3: larger active star.
[14:26] Speaker 2: Okay.
[14:26] Speaker 3: The white dwarf's gravity slowly siphons gas off its companion.
[14:30] Speaker 3: As it steals this matter, the white dwarf gets heavier
[14:32] Speaker 3: and heavier.
[14:33] Speaker 2: It's just gorging itself on star gas. Exactly.
[14:35] Speaker 3: Until it hits a very specific mathematical limit called the
[14:38] Speaker 3: Chandrasekhar limit, which is exactly 1.44 times the mass of
[14:42] Speaker 3: our sun. Right. At that exact weight, the pressure at
[14:46] Speaker 3: the core becomes so intense that carbon fusion ignites. the
[14:50] Speaker 3: entire white dwarf detonates in a thermonuclear explosion.
[14:53] Speaker 2: Wow.
[14:54] Speaker 3: Because they all trigger at that exact same mass limit
[14:57] Speaker 3: of 1.44 solar masses, the physics dictates that the resulting
[15:01] Speaker 3: explosion should yield roughly the same intrinsic brightness every single time.
[15:06] Speaker 2: Okay, so if it's like a 100-watt light bulb and
[15:09] Speaker 2: you see one that looks incredibly dim, you can calculate
[15:13] Speaker 2: exactly how far away it must be based on how
[15:16] Speaker 2: much the light has faded.
[15:17] Speaker 3: That is the exact principle, yes.
[15:18] Speaker 2: But surely there's a massive margin of error there.
[15:20] Speaker 3: Yeah.
[15:20] Speaker 2: What if there's like space dust between us and the
[15:24] Speaker 2: supernova absorbing the light and making it look dimmer than
[15:27] Speaker 2: it actually is? Yeah. Or what if a white dwarf
[15:29] Speaker 2: merges with another white dwarf instead of slowly siphoning gas?
[15:33] Speaker 2: That would ruin the standard candle, wouldn't it?
[15:35] Speaker 3: You are hitting on the exact controversies that keep cosmologists
[15:38] Speaker 3: awake at night. Dust extinction is a massive problem.
[15:41] Speaker 2: You would.
[15:42] Speaker 3: And variations in the chemical makeup, the metallicity of older
[15:46] Speaker 3: stars versus younger stars, can also subtly change the brightness
[15:49] Speaker 3: of the explosion. There are outliers and weird mergers that
[15:53] Speaker 3: don't fit the perfect model.
[15:55] Speaker 2: So how can we trust the data to overhaul general relativity?
[15:58] Speaker 3: This is where Roman's sheer scale solves the problem. If
[16:03] Speaker 3: you only observe 10 supernovae, a single weird merger or
[16:07] Speaker 3: a dense patch of dust will completely skew your data.
[16:10] Speaker 2: Right.
[16:11] Speaker 3: But Roman's field of view is so massive, it doesn't
[16:14] Speaker 3: have to painstakingly search for these explosions one by one.
[16:18] Speaker 3: It is going to watch enormous regions of the sky
[16:20] Speaker 3: continuously and monitor thousands upon thousands of these gigantic explosions.
[16:25] Speaker 2: The statistical power of large numbers.
[16:27] Speaker 3: Yes. When you have a data set of tens of
[16:29] Speaker 3: thousands of supernovae, the weird mergers and the dusty anomalies
[16:33] Speaker 3: can just be filtered out as statistical noise.
[16:35] Speaker 2: That makes total sense.
[16:36] Speaker 3: The true underlying curve of the universe's expansion history will
[16:40] Speaker 3: emerge with unprecedented precision. By comparing the brightness of these
[16:44] Speaker 3: thousands of standard candles to their redshift, how much their
[16:48] Speaker 3: light has stretched, we can chart exactly how the expansion
[16:52] Speaker 3: of the universe has accelerated over billions of years.
[16:55] Speaker 2: Okay, so supernovae give us an incredible timeline of this
[16:58] Speaker 2: cosmic expansion. But to really understand what dark energy is
[17:02] Speaker 2: doing to the structure of the universe... Roman has to
[17:05] Speaker 2: map the actual matter within it.
[17:06] Speaker 3: Yes, specifically the dark matter.
[17:08] Speaker 2: Right, because dark energy is pushing the universe apart. But
[17:12] Speaker 2: dark matter is the gravitational glue trying to hold it together.
[17:15] Speaker 3: And dark matter makes up about 27% of the universe.
[17:19] Speaker 3: Compared to the 5% that is ordinary matter, the stars, planets,
[17:23] Speaker 3: and us, dark matter is the dominant structural force.
[17:26] Speaker 2: But it doesn't interact with light. It doesn't emit light,
[17:30] Speaker 2: reflect light, or block light. Nope. So we hit the
[17:33] Speaker 2: same wall. How do you map an invisible skeleton?
[17:36] Speaker 3: You look for what it bends.
[17:37] Speaker 2: What it bends.
[17:38] Speaker 3: Yeah, this relies on one of the most mind-bending concepts
[17:41] Speaker 3: in astrophysics, weak gravitational lensing.
[17:44] Speaker 2: Okay, walk me through that.
[17:45] Speaker 3: We go back to Einstein's general relativity. Mass bends spacetime.
[17:51] Speaker 3: If you put a heavy bowling ball on a trampoline,
[17:54] Speaker 3: it creates a dip in the fabric.
[17:55] Speaker 2: Sure.
[17:56] Speaker 3: Spacetime acts the exact same way. Light traveling from a
[18:00] Speaker 3: distant background galaxy gets subtly distorted by the gravity of
[18:03] Speaker 3: whatever mass happens to sit between that galaxy and Earth.
[18:06] Speaker 2: Okay, let me try a grounded analogy here. Imagine looking
[18:09] Speaker 2: at a distant street lamp through an old, warped, wavy
[18:13] Speaker 2: pane of glass. Okay. The street lamp looks distorted, but
[18:17] Speaker 2: the light coming from the bulb isn't actually bent. It's
[18:20] Speaker 2: the glass you were looking through that is bent. Right, right.
[18:23] Speaker 2: If you study the distortion of the street lamp carefully enough,
[18:26] Speaker 2: You can actually draw a perfect topographical map of the
[18:29] Speaker 2: imperfections in the invisible pane of glass.
[18:31] Speaker 3: That is exactly what Roman is doing on a cosmic scale.
[18:35] Speaker 3: The invisible pane of glass is the dark matter scattered
[18:37] Speaker 3: throughout the universe, and the street lamps are the billions
[18:40] Speaker 3: of background galaxies.
[18:42] Speaker 2: I still see a flaw here, though. If we are
[18:44] Speaker 2: looking at one distant galaxy, and it looks stretched out,
[18:49] Speaker 2: how do we know it's being distorted by invisible dark matter?
[18:52] Speaker 2: I mean, galaxies come in all sorts of chaotic, messy
[18:55] Speaker 2: shapes naturally. They do. When two galaxies collide, they look
[18:58] Speaker 2: incredibly stretched. So how do you separate the natural, weird
[19:02] Speaker 2: shape of a galaxy from the optical illusion caused by
[19:06] Speaker 2: dark matter? You can't.
[19:07] Speaker 3: You can't do it with a single galaxy. A single
[19:10] Speaker 3: distorted street lamp tells you nothing about the glass. You
[19:13] Speaker 3: need enormous, staggering statistical samples. You need to look at
[19:18] Speaker 3: Billions of galaxies.
[19:19] Speaker 2: So again, the sheer scale of the WFI is the
[19:22] Speaker 2: only way to solve the problem.
[19:23] Speaker 3: Precisely. When you average out the shapes of billions of
[19:25] Speaker 3: galaxies over a massive swath of the sky, you can
[19:29] Speaker 3: assume that their natural physical orientations are totally random.
[19:33] Speaker 2: Some are tilted up, some are down.
[19:34] Speaker 3: Exactly. Some are circular, some are elongated. When you average
[19:38] Speaker 3: 100 million random shapes together, you should just get a
[19:40] Speaker 3: perfect circle.
[19:41] Speaker 2: Because the randomness cancels itself out. Yes.
[19:44] Speaker 3: So if you average a massive cluster of galaxies together
[19:47] Speaker 3: and the result is not a perfect circle, if there
[19:50] Speaker 3: is a tiny residual stretching in one specific direction, that
[19:54] Speaker 3: coherent stretching is the fingerprint of dark matter. The gravitational
[19:59] Speaker 3: mass sitting in the foreground is subtly warping all the
[20:02] Speaker 3: background light in a systematic way.
[20:04] Speaker 2: And this allows astronomers to build a 3D map because
[20:07] Speaker 2: you can look at galaxies at different distances, different redshifts,
[20:10] Speaker 2: and see how the dark matter distortion changes as you
[20:13] Speaker 2: look deeper and deeper into time.
[20:15] Speaker 3: This technique is called cosmic shear tomography. Roman will literally
[20:19] Speaker 3: map the invisible scaffolding of the universe, watching how this
[20:22] Speaker 3: dark matter skeleton has grown and clumped together over billions
[20:26] Speaker 3: of years, all while dark energy tries to rip it apart.
[20:30] Speaker 2: This actually brings up a crucial point about how science
[20:33] Speaker 2: operates at this level. We have the supernovae giving us
[20:35] Speaker 2: the expansion rate of the universe. And we have weak
[20:38] Speaker 2: lensing giving us the structural map of dark matter. Right.
[20:41] Speaker 2: Why do we need both on the same telescope?
[20:43] Speaker 3: Scientists demand redundancy, especially when the stakes are this high.
[20:48] Speaker 3: If you are going to tell the world that Einstein's
[20:50] Speaker 3: fundamental theories need a patch, you cannot rely on a
[20:54] Speaker 3: single experimental method.
[20:56] Speaker 2: Because if the supernova data is skewed by something we
[20:59] Speaker 2: don't understand, we might draw entirely false conclusions about dark energy.
[21:03] Speaker 3: Exactly. The data from the supernovae and the data from
[21:07] Speaker 3: the weak lensing are measuring two different things. Supernovae measure
[21:11] Speaker 3: the geometric expansion of space. Weak lensing measures the growth
[21:15] Speaker 3: of structure within that space.
[21:17] Speaker 2: Okay, I see.
[21:17] Speaker 3: These two measurements must independently converge on the exact same
[21:21] Speaker 3: answer regarding how dark energy behaves. If they agree, you
[21:26] Speaker 3: have a paradigm-shifting discovery. If they disagree, you have an
[21:29] Speaker 3: even bigger mystery on your hands because it means our
[21:31] Speaker 3: fundamental physics are completely broken.
[21:34] Speaker 2: It's like the ultimate double-check mechanism built right into the
[21:36] Speaker 2: mission architecture.
[21:37] Speaker 3: Absolutely.
[21:38] Speaker 2: And the rules of physics apply everywhere. So the exact
[21:40] Speaker 2: same gravitational trick that lensing effect used to map dark
[21:43] Speaker 2: matter across billions of light years can also be used
[21:47] Speaker 2: on a microscopic field, right?
[21:49] Speaker 3: Yes, it can.
[21:50] Speaker 2: Like right here in our own galactic backyard to find
[21:53] Speaker 2: hidden worlds.
[21:55] Speaker 3: We are talking about the microlensing revolution. Roman is not
[21:58] Speaker 3: just a cosmology machine mapping the edge of the universe.
[22:02] Speaker 3: It is arguably going to be one of the most
[22:04] Speaker 3: powerful exoplanet discovery observatories ever built.
[22:08] Speaker 2: That's just wild. It is hunting for exoplanets in a
[22:12] Speaker 2: completely different way than the famous missions we already know,
[22:15] Speaker 2: like the Kepler telescope or the TESS mission.
[22:18] Speaker 1: Yeah.
[22:19] Speaker 2: Let's break down gravitational microlensing, because this relies on an
[22:23] Speaker 2: incredibly lucky transient cosmic alignment, right?
[22:25] Speaker 1: It does.
[22:26] Speaker 3: It requires two stars to almost perfectly align from Earth's perspective.
[22:30] Speaker 3: Imagine a background star far away and a foreground star
[22:34] Speaker 3: closer to us that drifts right in front of it.
[22:36] Speaker 2: Okay.
[22:36] Speaker 3: As we just discussed with dark matter, the gravity of
[22:38] Speaker 3: that foreground star bends spacetime. As it passes in front,
[22:42] Speaker 3: it acts like a massive magnifying glass, taking the light
[22:45] Speaker 3: from the background star and temporarily bending it toward Earth.
[22:48] Speaker 2: Making the star appear much, much brighter for, what, a
[22:50] Speaker 2: few weeks? Yeah, exactly. So the star slowly gets brighter
[22:54] Speaker 2: as the foreground star's gravity passes over it and then
[22:57] Speaker 2: slowly dims as it drifts away. You get this Smooth,
[23:00] Speaker 2: symmetrical curve of light.
[23:02] Speaker 3: But if that foreground star has a planet orbiting it,
[23:06] Speaker 3: that planet has its own tiny bit of mass. It
[23:09] Speaker 3: creates its own tiny little dent in the trampoline of space-time.
[23:12] Speaker 2: So what happens to the light curve when the planet's
[23:15] Speaker 2: gravity hits it?
[23:16] Speaker 3: As the main magnification is happening, that planet's tiny gravity
[23:20] Speaker 3: adds a sudden, temporary spike to the magnification curve.
[23:23] Speaker 2: Oh, wow.
[23:24] Speaker 3: You see the smooth brightening of the background star, and
[23:26] Speaker 3: then suddenly... A tiny, sharp spike of extra light that
[23:31] Speaker 3: might last for a few hours or a few days,
[23:33] Speaker 3: and then it goes back to a smooth curve.
[23:35] Speaker 2: And that brief spike is the unmistakable signature of a
[23:39] Speaker 2: hidden planet.
[23:39] Speaker 3: Exactly.
[23:40] Speaker 2: I have to challenge the efficiency of this, though.
[23:42] Speaker 3: Go for it.
[23:42] Speaker 2: Space is incredibly vast and mostly empty. If this method
[23:46] Speaker 2: requires two stars to perfectly align from our specific vantage
[23:49] Speaker 2: point on Earth, aren't we going to be waiting forever?
[23:52] Speaker 3: It seems like it, yeah.
[23:53] Speaker 2: How is this an efficient way to find planets... compared
[23:57] Speaker 2: to the transit method that Kepler used. I mean, Kepler
[24:00] Speaker 2: just stared at stars and waited for a planet to
[24:03] Speaker 2: pass in front and block a tiny bit of light.
[24:05] Speaker 3: You are absolutely correct that the probability of any single
[24:09] Speaker 3: star aligning perfectly with a background star is vanishingly small.
[24:13] Speaker 3: Einstein actually wrote a paper on microlensing back in 1936
[24:17] Speaker 3: and concluded that the effect would never be observed because
[24:20] Speaker 3: the chances were just so low.
[24:22] Speaker 2: Really? Einstein doubted it?
[24:24] Speaker 3: He did. But Einstein didn't anticipate the technology we have today.
[24:28] Speaker 2: So how do you beat the low probability?
[24:30] Speaker 3: You look at a massive crowd. Roman isn't going to
[24:33] Speaker 3: look at empty space. It is going to point its
[24:35] Speaker 3: bay window directly toward the galactic bulge.
[24:38] Speaker 2: The center of the galaxy.
[24:39] Speaker 3: Yes, the incredibly dense, crowded center of the Milky Way galaxy.
[24:43] Speaker 3: It is going to monitor 100 million stars simultaneously. When
[24:46] Speaker 3: you monitor 100 million stars, those impossible alignments happen thousands
[24:51] Speaker 3: of times a year.
[24:52] Speaker 2: That's brilliant. And the reason we need microlensing is because
[24:54] Speaker 2: missions like Kepler and TESS have an inherent observational bias.
[24:59] Speaker 3: Huge bias, yes.
[25:00] Speaker 2: The transit method heavily favors finding large planets that orbit
[25:04] Speaker 2: very close to their host stars. They transit often, every
[25:08] Speaker 2: few days or weeks, and because they are large, they
[25:10] Speaker 2: block a lot of light. Right. It's incredibly difficult for
[25:14] Speaker 2: those telescopes to find a small, rocky planet like Earth
[25:17] Speaker 2: that takes an entire year to orbit. Because you'd have
[25:20] Speaker 2: to stare at the star for three solid years just
[25:23] Speaker 2: to see three transits and confirm the pattern.
[25:25] Speaker 3: Exactly. If alien astronomers were using the transit method to
[25:29] Speaker 3: look at our solar system, they would likely miss Earth completely.
[25:32] Speaker 2: Really?
[25:33] Speaker 3: Oh, yeah. And they would definitely miss Jupiter or Saturn
[25:36] Speaker 3: because a planet like Saturn takes nearly 30 years to
[25:39] Speaker 3: orbit the sun. It just doesn't cross the star often
[25:42] Speaker 3: enough from a distant perspective.
[25:44] Speaker 2: Wow. So microlensing discovers exactly what other telescopes are blind to.
[25:48] Speaker 3: Yes. It is highly sensitive to small, rocky planets. It
[25:52] Speaker 3: can find planets orbiting far out from their stars in
[25:55] Speaker 3: regions equivalent to our outer solar system where water would
[25:58] Speaker 3: be frozen solid.
[25:59] Speaker 2: And it can also find the most chaotic objects in
[26:02] Speaker 2: the galaxy.
[26:03] Speaker 3: Rogue planets.
[26:04] Speaker 2: Yes, the rogues. The wandering ghosts of the Milky Way.
[26:08] Speaker 2: I love this concept. How does a planet even become
[26:11] Speaker 2: a rogue?
[26:12] Speaker 3: Well, planetary formation is a violently chaotic process.
[26:16] Speaker 2: Like a cosmic demolition derby.
[26:17] Speaker 3: Pretty much. In the early days of a solar system,
[26:20] Speaker 3: you have gas giants forming and migrating inward or outward.
[26:24] Speaker 3: As massive planets like Jupiter shift their orbits, their gravitational
[26:28] Speaker 3: pull acts like a bowling ball crashing through a set
[26:30] Speaker 3: of pins.
[26:31] Speaker 2: So smaller rocky planets or ice giants get caught in
[26:34] Speaker 2: these gravitational slingshots.
[26:36] Speaker 3: Yes. They get accelerated to escape velocity and are violently
[26:39] Speaker 3: ejected from their solar systems entirely.
[26:42] Speaker 2: They're just thrown out into the interstellar void.
[26:44] Speaker 1: Yep.
[26:45] Speaker 3: They wander the dark spaces of the Milky Way, completely
[26:48] Speaker 3: unattached to any star, frozen and alone. Because they emit
[26:52] Speaker 3: no light and orbit no star, they are entirely invisible
[26:55] Speaker 3: to telescopes like Kepler or TESS.
[26:57] Speaker 2: But microlensing can catch them.
[26:59] Speaker 3: Exactly. If a rogue planet drifts perfectly in front of
[27:02] Speaker 3: a background star, it doesn't have a host star to
[27:05] Speaker 3: create a long, smooth magnification curve.
[27:08] Speaker 2: Instead, you just see the background star suddenly spike in
[27:11] Speaker 2: brightness for a few hours, caused entirely by the rogue
[27:14] Speaker 2: planet's gravity, and then fade back to normal.
[27:17] Speaker 3: A brief, isolated blip. Roman is expected to find hundreds
[27:22] Speaker 3: of these wandering ghosts.
[27:23] Speaker 2: Some models suggest there might be more rogue planets in
[27:26] Speaker 2: the Milky Way than there are stars.
[27:28] Speaker 3: Which is just crazy to think about, and it's going
[27:30] Speaker 3: to trigger a massive demographic census.
[27:33] Speaker 2: Right, because whenever you look up at the night sky,
[27:36] Speaker 2: the profound question is always, are we an anomaly? Is
[27:40] Speaker 2: our solar system normal, with our neat little rocky planets
[27:44] Speaker 2: tucked in close and the gas giants sitting peacefully out
[27:47] Speaker 2: in the suburbs?
[27:48] Speaker 3: Or are we an absolute cosmic freak?
[27:51] Speaker 2: A lot of the systems we've found so far look
[27:53] Speaker 2: nothing like ours. We find hot Jupiters, massive gas giants
[27:58] Speaker 2: skimming the actual surfaces of their suns, completing an orbit
[28:01] Speaker 2: in three days. Yeah. We find chaotic, packed systems where
[28:05] Speaker 2: planets are constantly tugging on each other.
[28:06] Speaker 3: But again, that is the bias of our previous instruments.
[28:09] Speaker 3: We find hot Jupiters because they are the easiest to
[28:11] Speaker 3: see with the transit method.
[28:13] Speaker 2: Or the data is skewed.
[28:14] Speaker 3: Roman will fill in the missing gaps in our planetary census.
[28:18] Speaker 3: By finding the outer planets, the cold planets, the rocky planets,
[28:21] Speaker 3: and the rogues, it will finally give us a complete
[28:24] Speaker 3: statistical picture of how planetary systems truly form and evolve
[28:28] Speaker 3: across the galaxy.
[28:29] Speaker 2: Microlensing is brilliant, but it is an indirect measurement. You're
[28:33] Speaker 2: basically waiting for a gravitational shadow. pass by. But Rowan
[28:38] Speaker 2: carries a second, completely different instrument designed to do something
[28:42] Speaker 2: much more aggressive and direct, doesn't it?
[28:44] Speaker 3: Yes. The technological wildcard of the mission.
[28:46] Speaker 2: The coronagraph instrument. That's the one.
[28:48] Speaker 3: And this is a radical departure from the wide field instrument.
[28:51] Speaker 3: The WFI is about scanning huge panoramic fields. The coronagraph
[28:55] Speaker 3: is about picking a single individual nearby star and Staring
[28:59] Speaker 3: intensely at it and doing something nearly impossible.
[29:01] Speaker 2: Taking a direct photograph of a planet orbiting it.
[29:04] Speaker 3: Taking a literal photograph of an alien world.
[29:06] Speaker 2: The extreme challenge of this cannot be overstated. Stars are
[29:10] Speaker 2: obnoxiously bright. I read an analogy that trying to stare
[29:13] Speaker 2: at an Earth-like planet next to a star is like
[29:16] Speaker 2: trying to spot a single firefly next to a lighthouse.
[29:19] Speaker 3: It's a common analogy, yeah.
[29:20] Speaker 2: But I feel like that cliche undersells the physics. It's
[29:24] Speaker 2: more like trying to spot a single speck Thank you
[29:27] Speaker 2: for watching. I mean, that is incredibly.
[29:42] Speaker 3: Specific, but honestly, it's spot on. The star outshines the
[29:45] Speaker 3: planet by a factor of up to 10 billion. The
[29:49] Speaker 3: light from the star simply washes out everything around it
[29:52] Speaker 3: in a massive glare.
[29:53] Speaker 2: So how do you even deal with that? A traditional
[29:55] Speaker 2: coronagraph uses physical masks, right? Basically small metal discs. to
[30:00] Speaker 2: block the light of the central star, creating an artificial
[30:03] Speaker 2: eclipse inside the telescope.
[30:04] Speaker 3: Exactly.
[30:05] Speaker 2: But even if you block the star, you still can't
[30:06] Speaker 2: see the planet, right? Because of diffraction. Right.
[30:09] Speaker 3: When light hits the edges of the telescope's mirror or
[30:12] Speaker 3: the struts holding the secondary mirror, the light waves bend
[30:15] Speaker 3: and scatter.
[30:16] Speaker 2: Make a mess.
[30:17] Speaker 3: A huge mess. This scattered light creates a halo of glare,
[30:21] Speaker 3: a messy, noisy optical artifact that completely drowns out the
[30:25] Speaker 3: faint speck of a planet. To overcome this, The coronagraph
[30:29] Speaker 3: on Roman employs literal engineering magic.
[30:32] Speaker 2: Deformable mirrors.
[30:33] Speaker 3: Deformable mirrors.
[30:34] Speaker 2: When you say deformable mirrors, my mind immediately goes to
[30:37] Speaker 2: a funhouse mirror. How do you precisely bend a mirror
[30:40] Speaker 2: in space?
[30:42] Speaker 3: Behind the reflective surface of these mirrors are thousands of tiny,
[30:46] Speaker 3: microscopic mechanical pistons called actuators. These actuators constantly push and
[30:51] Speaker 3: pull on the back of the mirror's surface in real time.
[30:54] Speaker 2: In real time?
[30:55] Speaker 3: Yes. They warp the shape of the glass to perfectly
[30:57] Speaker 3: counteract the scattered light and optical imperfections bouncing around inside
[31:01] Speaker 3: the telescope.
[31:02] Speaker 2: The engineering specs on this absolutely broke my brain when
[31:04] Speaker 2: I read them. NASA states that these actuators make corrections
[31:08] Speaker 2: to the mirror's surface that are smaller than the width
[31:10] Speaker 2: of a strand of human DNA.
[31:12] Speaker 3: It is a level of precision that is almost incomprehensible.
[31:15] Speaker 2: Less than a strand of DNA. Yeah.
[31:18] Speaker 3: The system analyzes the glare, calculates the exact counter shape
[31:22] Speaker 3: needed to cancel it out, and adjusts the mirror at
[31:25] Speaker 3: a submicroscopic level thousands of times a second. They essentially
[31:29] Speaker 3: carve out a dark hole in the glare, revealing the
[31:33] Speaker 3: infinitesimally faint speck of light that is a planet.
[31:36] Speaker 2: It's an active noise cancellation, but for light.
[31:39] Speaker 3: That's brilliant. Yes, exactly that. And it allows Roman to
[31:43] Speaker 3: photograph planets that are a billion times fainter than their
[31:46] Speaker 3: host stars. Wow. The coronagraph is also going to look
[31:49] Speaker 3: at debris disks, which are massive rings of leftover dust
[31:52] Speaker 3: and ice from when a planetary system was first forming.
[31:55] Speaker 2: Debris disks act like gravitational sandboxes, right? Very much so.
[31:58] Speaker 2: Even if a planet is too faint or too small
[32:00] Speaker 2: to be seen directly by the coronagraph, its gravity will
[32:03] Speaker 2: sweep through that dust. It carves out gaps, warps the edges,
[32:07] Speaker 2: and sculpts intricate patterns.
[32:08] Speaker 3: Like invisible footprints in the snow. By analyzing the architecture
[32:12] Speaker 3: of the dust, astronomers can detect the distinct gravitational footprint
[32:16] Speaker 3: of unseen planets.
[32:17] Speaker 2: We need to be clear about the coronagraph, though. NASA
[32:20] Speaker 2: is explicitly calling it a technology demonstration.
[32:23] Speaker 3: That is a highly vital distinction.
[32:25] Speaker 2: Right.
[32:26] Speaker 3: The coronagraph on Roman is a proof of concept. It
[32:29] Speaker 3: is there to prove that this wildly complex DNA-width actuator
[32:33] Speaker 3: technology can actually survive the violent shaking of a rocket
[32:37] Speaker 3: launch and work flawlessly in the harsh vacuum and thermal
[32:40] Speaker 3: extremes of space.
[32:42] Speaker 2: So while we hope it takes incredible images of giant
[32:45] Speaker 2: planets and dust disks... Its true purpose is paving the way.
[32:48] Speaker 3: Absolutely. Paving the way for the next generation of space telescopes.
[32:51] Speaker 2: Because if this tech works, we can scale it up.
[32:54] Speaker 2: We can build even bigger coronagraphs in the 20s, 30s,
[32:57] Speaker 2: and 40s, like the proposed Habitable Worlds Observatory, designed specifically
[33:03] Speaker 2: to directly image small, rocky, Earth-like worlds.
[33:07] Speaker 3: And pass their light through a spectrometer to look for oxygen,
[33:09] Speaker 3: water vapor, and methane in their atmospheres. We have to
[33:12] Speaker 3: learn to walk with Romans so we can run in
[33:14] Speaker 3: the next decade.
[33:15] Speaker 2: It is the technological bridge to the ultimate goal of
[33:18] Speaker 2: finding a second Earth. Let's pull back, though, and look
[33:20] Speaker 2: at the synergy of this entire endeavor. We have this
[33:23] Speaker 2: incredibly powerful panoramic surveyor, this cosmic mapmaker. But how does
[33:28] Speaker 2: it fit into the broader fleet of telescopes we already
[33:31] Speaker 2: have up there? The obvious elephant in the room is
[33:34] Speaker 2: the James Webb Space Telescope. It is. People might look
[33:37] Speaker 2: at Roman and ask, didn't we just launch the ultimate
[33:39] Speaker 2: telescope a few years ago? Is Roman meant to be
[33:43] Speaker 2: Webb's replacement?
[33:44] Speaker 3: That is a very common misconception. Roman and Webb are partners.
[33:48] Speaker 3: They are not competitors. They are designed to do entirely different,
[33:53] Speaker 3: highly complementary jobs.
[33:54] Speaker 2: So how do their roles differ in practice?
[33:57] Speaker 3: Think of Webb as the ultimate zoom lens. Webb is
[34:00] Speaker 3: extraordinarily sensitive. It has a massive 6.5 meter segmented mirror.
[34:06] Speaker 3: It can peer deeper into the universe and see fainter,
[34:09] Speaker 3: older objects than anything ever built by humanity.
[34:12] Speaker 2: But its field of view is very narrow.
[34:14] Speaker 3: Extremely narrow. If Webb wants to look at a distant galaxy,
[34:17] Speaker 3: it has to point and stare directly at that specific
[34:20] Speaker 3: pinhole of sky.
[34:21] Speaker 2: So Roman gives up some of that extreme depth and
[34:23] Speaker 2: sensitivity in exchange for its massive field of view. Roman
[34:27] Speaker 2: is the surveyor throwing the net incredibly wide. It scans
[34:30] Speaker 2: billions of stars and millions of galaxies, taking in the
[34:33] Speaker 2: entire landscape. and it looks for the anomalies.
[34:36] Speaker 3: Right. Once Roman finds something strange, a weird supernova curve,
[34:40] Speaker 3: an unexplained transient flash, a peculiar exoplanet signature, it flags
[34:46] Speaker 3: the coordinates.
[34:47] Speaker 2: And then Webb takes over.
[34:48] Speaker 3: Then, Webb serves as the high-powered follow-up observatory. Webb turns
[34:53] Speaker 3: its massive zoom lens to those exact coordinates and performs
[34:57] Speaker 3: the deep, highly sensitive chemical analysis.
[34:59] Speaker 2: So combining Roman's wide-field surveys with Webb's deep, targeted observations
[35:04] Speaker 2: gives the astronomical community a scientific capability that is vastly
[35:08] Speaker 2: greater than either telescope could ever deliver alone.
[35:10] Speaker 3: It's the ultimate tech team.
[35:12] Speaker 2: But there is a massive logistical hurdle to Roman's wide-net approach.
[35:16] Speaker 2: NASA estimates that Roman will beam back roughly 20 petabytes
[35:19] Speaker 2: of data over its primary five-year mission.
[35:21] Speaker 3: Yeah, and to try and conceptualize that volume of information,
[35:24] Speaker 3: a petabyte is one million gigabytes.
[35:26] Speaker 2: I mean, a human being couldn't possibly look at that
[35:29] Speaker 2: many images. You cannot have a team of exhausted grad
[35:32] Speaker 2: students sitting in a basement clicking through 20 petabytes of
[35:35] Speaker 2: wide-field infrared cosmos, visually searching for tiny dark matter distortions
[35:41] Speaker 2: or microlensing blips.
[35:42] Speaker 3: No, it is physically impossible. This is why Roman is
[35:44] Speaker 3: going to be a catalyst for revolution in computational science,
[35:47] Speaker 3: not just astronomy. Processing this 20-petabyte avalanche requires cutting-edge machine
[35:53] Speaker 3: learning and artificial intelligence.
[35:55] Speaker 2: I have a healthy skepticism about AI in scientific research, though.
[35:58] Speaker 3: That's completely fair.
[35:59] Speaker 2: How do we ensure that an algorithm trained to find
[36:02] Speaker 2: supernovae doesn't just hallucinate a discovery? If we are training
[36:07] Speaker 2: a neural network to look for patterns and it finds
[36:09] Speaker 2: a pattern, how do we know it's dark matter and
[36:12] Speaker 2: not just an artifact of the telescope's hardware?
[36:14] Speaker 3: That is the defining challenge of the data pipeline. You
[36:17] Speaker 3: cannot just feed raw data into an unsupervised neural network
[36:21] Speaker 3: and trust the output. The algorithms have to be rigorously
[36:24] Speaker 3: trained on simulated universe data before Roman even launches.
[36:27] Speaker 2: Wait, simulated universes?
[36:29] Speaker 3: Yes. We create massive, mathematically perfect simulations of the cosmos,
[36:35] Speaker 3: inject fake supernovae and artificial instrumental noise into the simulation,
[36:40] Speaker 3: and train the AI to perfectly distinguish a cosmic ray
[36:44] Speaker 3: hitting the detector from a genuine astrophysical event.
[36:47] Speaker 2: We are entering the era of AI astronomy. The algorithms
[36:50] Speaker 2: are becoming as crucial to the discovery process as the
[36:53] Speaker 2: mirrors and the detectors.
[36:55] Speaker 3: The science of how we process and calibrate the data
[36:58] Speaker 3: is advancing in tandem with the physical hardware.
[37:00] Speaker 2: Which leads to what might be the most exciting part
[37:02] Speaker 2: of this entire endeavor. The unknown unknowns.
[37:06] Speaker 3: Oh, absolutely.
[37:07] Speaker 2: We spent decades engineering Roman to answer very specific known questions.
[37:11] Speaker 2: We wanted to measure the acceleration of dark energy. We
[37:14] Speaker 2: wanted to map the cosmic web of dark matter. We
[37:17] Speaker 2: wanted to count the cold exoplanets and rogues.
[37:19] Speaker 3: But panoramic survey of this scale, continuously watching the sky
[37:23] Speaker 3: and generating petabytes of data, will inevitably capture things we
[37:26] Speaker 3: do not have theories for yet.
[37:28] Speaker 2: A data factory of this magnitude is guaranteed to capture
[37:31] Speaker 2: the bizarre. Strange transient flashes in the deep dark that
[37:34] Speaker 2: don't match any known supernova profile. Bizarre galactic formations that
[37:39] Speaker 2: defy our current models of how galaxies evolve. Completely unexplained
[37:43] Speaker 2: physics that refuse to fit comfortably into the neat little
[37:46] Speaker 2: boxes of our current textbooks.
[37:48] Speaker 3: That is the true beauty of a wide field survey.
[37:51] Speaker 3: It is not just looking for answers to the questions
[37:53] Speaker 3: we already know.
[37:53] Speaker 2: How to ask.
[37:54] Speaker 3: It provides the raw, unedited canvas of the universe. And
[37:58] Speaker 3: it operates as an engine designed to generate entirely new
[38:01] Speaker 3: questions for the next century of physics.
[38:04] Speaker 2: So to bring us back to this historic morning, after
[38:07] Speaker 2: the Falcon Heavy lifts off today and pushes Roman away
[38:10] Speaker 2: from Earth... What is the actual destination? It's not just
[38:13] Speaker 2: orbiting the Earth like Hubble, right?
[38:15] Speaker 3: No. Earth orbit is too warm, and the Earth physically
[38:17] Speaker 3: blocks too much of the sky. Roman is heading for
[38:20] Speaker 3: the second Lagrange point, or L2, which is about a
[38:23] Speaker 3: million miles away from Earth in the opposite direction of
[38:26] Speaker 3: the Sun.
[38:27] Speaker 2: The same neighborhood as the James Webb Space Telescope.
[38:29] Speaker 3: Yes, they're neighbors. L2 provides an incredibly stable gravitational and
[38:34] Speaker 3: thermal environment. The Sun, Earth, and Moon are always in
[38:37] Speaker 3: the same direction. allowing Romans' massive sunshield to permanently block
[38:41] Speaker 3: their heat and light, keeping those infrared detectors freezing cold.
[38:45] Speaker 2: After it arrives at L2, it will go through a
[38:48] Speaker 2: rigorous commissioning phase, deploying its systems, cooling down to operating temperatures,
[38:52] Speaker 2: calibrating the WFI and the coronagraph. And then it will
[38:56] Speaker 2: settle in.
[38:57] Speaker 3: It will.
[38:57] Speaker 2: For the next five to ten years, it will sit
[38:59] Speaker 2: quietly in the cold void, a silent sentinel opening its
[39:03] Speaker 2: bay window. catching ancient photons that had been traveling through
[39:07] Speaker 2: the terrifying expanses of space for billions of years, only
[39:10] Speaker 2: to end their journey striking a microchip, transforming into spectra, maps,
[39:15] Speaker 2: light curves, and the delicate silhouettes of brand new worlds.
[39:18] Speaker 3: It is a remarkable human achievement. We are taking the
[39:21] Speaker 3: measure of the cosmos on a scale that was frankly
[39:23] Speaker 3: unimaginable when Nancy Grace Roman first started fighting for space-based astronomy.
[39:28] Speaker 2: I want to leave you with one final... lingering idea
[39:31] Speaker 2: to ponder as we watch this launch today. For all
[39:34] Speaker 2: of human history, from the first astronomers charting planetary movements
[39:38] Speaker 2: on clay tablets to Galileo grinding his own glass lenses,
[39:42] Speaker 2: all the way up to the magnificent Hubble and Webb telescopes,
[39:45] Speaker 2: Our understanding of the universe has been strictly limited by
[39:48] Speaker 2: the narrowness of our vision. Right. We've only ever been
[39:51] Speaker 2: able to look at the cosmos one tiny, painstaking pinhole
[39:55] Speaker 2: at a time.
[39:55] Speaker 3: A magnificent pinhole, but a pinhole nonetheless.
[39:58] Speaker 2: Looking through that tiny pinhole has given us expanding galaxies,
[40:01] Speaker 2: black holes, the cosmic microwave background, dark matter, and thousands
[40:05] Speaker 2: of exoplanets. The provocative thought is this. Roman is essentially
[40:10] Speaker 2: opening the world's eyes wide for the very first time.
[40:13] Speaker 2: If looking through a tiny pinhole yielded a universe so
[40:16] Speaker 2: endlessly complex and bizarre, what completely terrifying and paradigm-shattering realities
[40:20] Speaker 2: are hiding just outside our current field of view, waiting
[40:23] Speaker 2: to be illuminated in a single massive panoramic snapshot?
[40:26] Speaker 3: We are about to find out.
[40:28] Speaker 2: Thank you so much for joining us for this conversation
[40:31] Speaker 2: on the dawn of a new observational era. Enjoy the
[40:34] Speaker 2: launch today. Keep looking up.

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