Today, Explained - The James Webb Space Telescope
Episode Date: January 18, 2022This Sunday, the greatest telescope in the history of humanity is scheduled to reach its destination nearly a million miles away from Earth. Vox’s Unexplainable explored what it will do when it gets... there. Transcript at vox.com/todayexplained Support Today, Explained by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices
Transcript
Discussion (0)
Get groceries delivered across the GTA from Real Canadian Superstore with PC Express.
Shop online for super prices and super savings.
Try it today and get up to $75 in PC Optimum Points.
Visit superstore.ca to get started.
It's Today Explained. I'm Sean Ramos from we're coming off a long weekend here. Martin Luther King Jr. Day for our international listeners. I had a chance to go a few places like a restaurant
and a grocery store. Very exciting stuff. The restaurant had a sign on the door saying it was
closing early because of pandemic related staff shortages. And while I was shopping,
someone came on the
loudspeaker at the grocery store and said they were shutting down due to pandemic-related staff
shortages. Get to the checkout aisle now. We want you out of here. And as I was checking out,
I kind of wondered, do daily news shows ever shut down early because of pandemic-related
staff shortages? It turns out they do. Several members of our small but mighty Today Explained
team have come down with this
coronavirus you've been hearing about recently. I can't tell you which ones. I don't want to
violate their hippos, but we need a minute to recover here. Instead of locking up early,
we're going to look up to the sky with the help of our friends over at the Unexplainable podcast.
Back in September, they spent two weeks exploring the science of the most powerful telescope humanity has ever designed.
Since then, this telescope has been successfully launched into space, and it's on its way to its final destination.
It'll get there this Sunday.
It's called the James Webb Telescope.
You've probably heard about it.
Your favorite space person is very thrilled about this news. You'll
hear Noam and Brian from Unexplainable talk about the launch of Webb in the future tense. You'll
hear them talk about whether or not it can successfully unfold in space. Ignore that stuff.
It's all happened. The thing launched on Christmas. It was an interstellar gift to the world. It's
since successfully unfolded itself in space. That's not important anymore.
But what you will hear them talk about and what is very important is why this telescope
is such a game changer for humanity. Pay attention to that. That's the good stuff.
Unexplainable ran these two episodes in back to back weeks. We are going to run them in back to
back days on our show today and tomorrow.
We'll be back and healthy
with some fresh Today Explained for you
on Thursday.
Live long and prosper.
T-minus 10, go for main engine start.
We are go for main engine start.
T-minus 6, 5, 4, 3, 2, 1, and liftoff of the space shuttle discovery with the
hubble space telescope our window on the universe this was the picture that nasa managers all over
the world were waiting for the hubble space telescope is released the clearest picture
ever seen in the history of astronomy scientists expect it will revolutionize our understanding of how far we have come
and still have to go.
How far we have come.
381 miles above the Earth.
We see stars, blobs, pillars.
Floating in orbit.
The Hubble Space Telescope.
Each one tells us how far we have come.
When the Hubble Space Telescope launched in 1990, it was a gigantic leap forward.
Hubble was something that scientists dreamed about having for decades.
Reporter Brian Resnick.
On Earth, you know, we can put telescopes on mountaintops, but space, putting a telescope in space, that's kind of like the ultimate mountaintop.
And from its orbit around the Earth, Hubble revolutionized our understanding of the universe.
Hubble taught us that the universe is expanding faster and faster all the time.
It helped us determine about how old the universe is. And this is not a small thing. It's given us these ridiculously beautiful images.
The Orion Nebula, the deep
field, the pillars of creation. But now we're on the verge of a new era. This is the future,
NASA's James Webb Space Telescope. The Webb Telescope, which is named after a former NASA
administrator, is the biggest, most powerful space telescope ever built. It's a grand scientific undertaking.
A space telescope so sensitive,
it can peer deeper into the cosmos than any previous orbiting observatory.
Our reporter Brian's been talking about the Webb
since we launched this show.
And he's been speaking to tons of astronomers
who all have research projects lined up.
This is really the reason why I wanted to bring it to the show,
because this is a machine for answering unanswered questions.
I definitely think that Webb will be a paradigm shifting telescope.
We're going right up to the edge of the observable universe.
The Webb represents the culmination of decades, if not centuries, of astronomy.
We will find things that completely surprise us.
It'll give us a view of parts of the universe we've never seen before.
Things that fundamentally change the way that we understand the universe.
I'm Noam Hassenfeld, and for the next two weeks on Unexplainable,
we'll be diving into the question-answering machine that is the James Webb Space Telescope.
How far we have come.
And still have to go. How far we have come. And still have to go.
How far we have come.
Each one tells us.
How far we have come.
And still have to go.
How far we have come.
Each one tells us. How far we have come.
Okay, Brian, before we get to some of the unanswered questions that the Webb telescope
is going to let scientists try and answer, let's just start with the telescope itself.
What makes the Webb so powerful?
So I talked to Amber Straughan.
She's a NASA astrophysicist.
She's worked on Webb for years, and she really pointed out there are two key ways that the Webb improves on Hubble.
The first way is really just the size.
It's enormous. It's much bigger than the Hubble.
Hubble's about the size of a school bus. Webb stands about four stories tall.
It's about the size of a tennis court. So it is absolutely huge.
And bigger with a telescope is inherently better?
Yeah. So especially when it comes to this kind of telescope,
the key component is the mirror.
So a telescope mirror, you can sort of think of it like a light bucket.
So the bigger it is, the more light it can just collect.
And Webb has this light collecting area that's more than six times bigger than Hubble.
And then also the bigger it is, the finer resolution it can see.
And not only is it large, it's like a gorgeous golden honeycomb with all these different
segments of hexagons.
Here, let me send you.
Oh, cool.
I mean, this looks like something that I would see in a sci-fi movie and be like, oh, wouldn't
it be cool if they made things that looked like that?
Yeah, and they did.
And because it's so big, there aren't any
rockets that are big enough to launch it fully deployed. So the whole thing has to be folded up
to fit inside a rocket. The engineers had to find a way to kind of origami it into a smaller package
so it can actually fit on a rocket ship. And then once it launches, it will have to assemble itself
in space. I'm sorry, assemble itself? Yeah, it's
supposed to. So that whole process of building a deployable telescope in space is sort of the
source of a lot of the engineering challenges. Okay, so the web is super big. What's the second
important difference between the Webb and the Hubble?
The type of light it collects.
Webb is an infrared telescope, so that means it sees the universe in infrared light,
light that's a little bit more red than what our eyes can see.
Hubble can detect visible light, which is what our eyes can see,
but Webb can see what's invisible to our eyes.
And as far as all the frequencies of light go, red's at the lower end of the spectrum, right?
Like longer wavelengths, lower energy? Yeah. So light comes in a lot of different
flavors. So blue would be very high frequency. And then if it gets lower and lower frequency,
it gets redder and redder and redder, and then it drops into infrared.
And what's the advantage of having a telescope that can see infrared?
This relates to something we were talking about a couple of months ago on our episode on Henrietta Leavitt and the end of the universe.
We talked about how the universe is constantly expanding, right?
Right. More space all the time.
So scientists discovered that by looking at the quality of light coming from different parts of space.
And it turned out things that were farther away from us looked redder than the things that are closer to us.
This is called redshifting.
Space is expanding.
And as light travels through space from those distant galaxies, the light is literally stretched by the expansion of space.
Imagine a star that's really far away,
and the light from that star to get to us has to travel through space.
But that space itself is expanding,
and that space is stretching the light
until it eventually gets so, it drops into infrared.
And what that means here is that Webb,
because it collects infrared light,
it can see these very far away things
that Hubble just couldn't see.
Things that are so far away,
the light might have started off in the visible spectrum,
but is now infrared.
So the Webb will literally be seeing things
that are so far away that no one's ever
seen them before. Yeah, infrared telescopes are really sensitive. And because of that,
the telescope has to be very, very, very cold. Because anything that is warm will glow in
infrared. You and I, all your listeners, we're all glowing in infrared light. If the telescope
was warm, it would just glow and see itself. So to keep it cold,
the Webb actually needs to be sent really far away from the Earth. Webb is going to be a million
miles away. That's about four times further than the moon. What? It's going to be at a place where
it's shielded from the heat and light of the sun and the Earth. Sorry, four times the distance of
the moon? Yeah, yeah, really very far. So this is not going
to be orbiting the Earth. This is going to be orbiting the sun, but also keeping itself in
line with the Earth. It's called a Lagrange point. So it's orbiting the sun with us, but like
at the same pace that we're orbiting the sun? Yeah, it's pretty wild. That is insanely cool.
And when you add all those together,
you know, the size of the mirror,
the wavelength of light it will see,
what we're going to get is a telescope
that's about 100 times more powerful than Hubble,
if you can even imagine that.
This is a super high-stakes mission.
The web, it's going to be nearly a million miles away.
And once it's there,
we can't fix it. And what's haunting this whole project is that the Hubble needed to be fixed.
After it was launched in 1990, the images from it just came back fuzzy.
But I am extremely concerned by the fact that after spending almost $2 billion over a 12-year
period, we only now find out that
this kind of mistake could occur. And it was kind of this national joke. Have you heard about the
problems with the Hubble Space Telescope? Yes. A billion and a half dollars, we put up a telescope
and it's out of focus. And so astronauts had to launch on a space shuttle and fix it,
give the Hubble reading glasses, so to speak.
And they could do that because Hubble was close enough to the Earth
where you could launch a shuttle and get there and fix it.
And they called the NASA official repairman.
And he said he'll be up there sometime in the 21st century between noon and five.
You build the greatest, biggest telescope that humanity's ever assembled, and it's like, oh, it's blurry.
Yeah, yeah. But you can't just go and fix the web if it breaks. It's way too far. It just has to work.
So have they been sort of like double-checking everything, like waiting a while to make sure they're not making any reading glasses mistakes?
Yeah, it's just taken such a long time to get here.
People were talking about the successor
to the Hubble before the Hubble even launched. And the James Webb Space Telescope was originally
supposed to launch in 2010 and cost around a billion dollars. Now the costs have ballooned
to $10 billion, and it's just way overdue. And they're still planning to launch it, right? That's the plan?
The plan is to launch by end of 2021. And this can change, so don't at me if it does change.
And then after it launches, there'll be some time it has to deploy, it has to do all these
things that we've talked about. Unfold in space?
Yeah, fingers crossed. But then, you know, the science will
start. And this is one of the things that really drew me to the story is that anyone can use the
Webb Space Telescope. What do you mean? Like there's like a terminal somewhere that you can
walk up to and like check out space? Yeah. Put your eye next to it. Put in a quarter? No, anyone
in the world can write a proposal, say, I want to use Webb to look at this.
Can we use it?
Yeah, yeah.
I wanted to know, too.
I asked Amber at NASA.
Absolutely.
I mean, you might need an astronomer friend to help you out.
Should we apply?
You know, I looked into it, and I think it's a little bit over our heads to do this.
Yeah, it's pretty competitive, to say the least.
So in March 2021, the Space Telescope Science Institute, which runs the Webb and other space telescopes,
they sent out emails to scientists who had applied to use the Webb.
And these scientists, on this day, were furiously checking their emails to see if, oh, were their proposals accepted?
And it was kind of like all huddling around and finding out who got parts in the school play.
It was an exciting day.
We totally felt like underdogs.
It feels like a dream.
It was honestly a truly amazing feeling.
I think I was just stunned for a good minute there.
I probably cried a little bit.
I'm pretty sure I jumped up out of my chair in my office and shouted out, yes!
And Brian, you've been talking to these scientists for the last few months, right?
Yeah, I've been talking to scientists who have been awarded time to use the telescope.
And these conversations, they just leave me with a big smile.
Like, just their sense of wonder and awe.
Like, these are people who get to explore the frontiers of the cosmos,
and they just have so many unanswered questions.
What kind of questions are they trying to answer?
Questions about the search for life in the universe,
questions about the beginning of time, about exploring strange new worlds that are way different than anything that exists in our solar system.
How strange?
Oh, I'll tell you. But just after the break.
Yes!
It's a lava planet.
Support for Today Explained comes from Ramp.
Ramp is the corporate card and spend management software designed to help you save time and put money back in your pocket.
Ramp says they give finance teams unprecedented control and insight into company spend. With Ramp, you're able to
issue cards to every employee with limits and restrictions and automate expense reporting
so you can stop wasting time at the end of every month. And now you can get $250 when you join Ramp. You can go to ramp.com slash explained,
ramp.com slash explained,
R-A-M-P dot com slash explained,
cards issued by Sutton Bank,
member FDIC,
terms and conditions apply. Apply. And no matter your team, your favorite player, or your style, there's something every NBA fan will love about BetMGM.
Download the app today and discover why BetMGM is your basketball home for the season.
Raise your game to the next level this year with BetMGM,
a sportsbook worth a slam dunk and authorized gaming partner of the NBA.
BetMGM.com for terms and conditions.
Must be 19 years of age or older to wager.
Ontario only.
Please play responsibly.
If you have any questions or concerns about your gambling or someone close to you,
please contact Connex Ontario at 1-866-531-2600
to speak to an advisor free of charge.
BetMGM operates pursuant to an operating agreement with iGaming Ontario.
Unexplainable. We're back. So is Brian.
Hey.
And we're talking about the upcoming James Webb telescope and all the unanswered questions it might allow scientists to answer.
So, Brian, what's the first unanswered question that scientists are trying to figure out with the web? Is there life on other worlds?
Big one to start with. Yeah. And, you know, they're looking for life and not, you know,
necessarily in our neighborhood, like on Mars or Venus, although there are searches for life on
those planets. But they're looking for life on worlds called exoplanets,
which are planets that revolve around stars that are not our sun.
So planets in like entirely different systems?
Yeah, yeah.
And scientists in the last decade or so have detected so many of them.
There's this exoplanet revolution.
But we've detected them with smaller telescopes,
and it's just hard to
know a lot about them. We just can't study them super well, but that's going to change. The web
is going to give us a whole new view onto exoplanets. I talked to an astronomer, Lisa Dang.
She's a PhD student at McGill University, and she's been awarded time on the web to study an
exoplanet. This is the first telescope proposal that I ever
submitted that was successful. It made me feel like an astronomer for the first time.
What kind of exoplanet is she looking at? Oh, this is so rad. So I was looking down the list
of projects approved for the web, and I just stopped at Lisa's because she's going to study
one of the most extreme planets we've ever discovered.
I want to use this James Webb Space Telescope to look at K2-141b, the lava planet.
A lava planet?
Yeah, like when we get outside of our solar system, planets can get really weird. It probably looks like hell.
So we know this planet is there, but we really don't know much more about it. We just haven't studied it in detail because we just haven't had a big enough telescope.
So I asked Lisa to help me imagine what could be there.
Oh, I have so many mental images of what this planet could look like.
This planet, the first thing to know about it is it's really close to its star.
It's so hot on this planet that you could sustain a temperature
that would melt the continent on the planet.
Anything on that surface
is just the hottest thing you can imagine.
So instead of having oceans of water like we have here,
we have oceans of lava on this planet.
The floor is lava.
But then there also could be weirder things.
So like this world isn't like an uninteresting place.
So things that I'm hoping to
look for is maybe clouds on this planet. But they wouldn't be like any clouds you've ever imagined
before. Instead of having, you know, clouds of water molecule like we have here, these planets
would have clouds made of rock. And these clouds, even if they're made of rock, they can still float
because the particles in them would be small enough. It's probably looking pitch black, like dark black clouds, but depending on the shape of
these particles, maybe they could be shinier cloud of crystals.
And then those clouds, they can do cloud things.
We can also have rain from these clouds.
It would be raining rock or like raining silicate.
It's truly one of the most extreme places we've discovered in the galaxy.
Okay, the lava planet seems really cool and all,
but why is the lava planet the place to start
if Lisa is trying to search for life?
It doesn't exactly seem like a place
where there would be life.
Yeah, it is a very extreme place.
If life exists there, it is a very extreme place if life
exists there, which is unlikely. It would be unlike any life that we can think of. But there's
a bigger picture reason why she's studying the lava planet. It's because it's the perfect place
for her to get really good at atmosphere hunting. Atmosphere hunting? So we don't know whether
these planets even have an atmosphere like you described on Earth. But in order to find life anywhere, we're pretty sure a planet needs to have an atmosphere.
And the lava planet is just this big, hot place that glows in infrared really brightly.
So it's going to be really visible for the Webb Space Telescope.
So it's just a perfect place to learn how to study atmospheres on other planets and
really refine the skills of analyzing them. So looking at a lava planet is kind of like
the first target that you want to try with James Webb before you go towards more temperate
rocky planets like Earth, for example. And how exactly would the Webb figure out
if a planet has an atmosphere? So what I am hoping to do with the James Webb Space Telescope
is basically to observe this planet as it completes a whole orbit.
When the planet crosses in front of its star,
it will come in between the star and the Webb telescope.
If there's an atmosphere there,
that atmosphere will change the quality of light.
So the atmosphere would act as a sort of filter.
And then from there,
like Lisa can actually create these whole weather maps of the planet.
So is she basically going to have to do this like one by one,
point the web at every single planet to see if it has an atmosphere?
Hopefully she doesn't have to do that all by herself. She's not alone here. She's not the
only scientist studying exoplanets. I spend most of my time,
not quite staring up at the stars, but trying to reveal their secrets. I talked to this guy,
Kevin Stevenson. He's a planetary scientist at the Johns Hopkins Applied Physics Lab.
It's exciting, right? This is the first step towards answering the question of, are we alone?
He's also been approved to use the web, and he wants to know if he can predict
whether planets have atmospheres or not before he even looks at them directly with the web.
How would you predict whether a planet would have an atmosphere?
So there's actually this really neat pattern that scientists find in our own solar system,
where they look at our solar
system and they catalog all the planetary bodies, the planets, the moons, and they see which ones
have atmospheres and which ones don't. And it turns out it's just a function of how big the
planets are and how warm they are. So this is a really neat trend that we see in our own solar
system. And the question is, does this trend apply to systems outside of our
solar system? Is it truly cosmic in nature? There are potentially billions of planets to
look at. And if we can just better predict which ones have atmospheres, then we can narrow it down.
We're like a step further in the direction of answering the huge question, are there other
habitable worlds?
And where do we go from there? I mean, where do we go from,
okay, these planets have atmospheres to, is there life on those planets?
Once we have confirmed that a planet has an atmosphere, the web can actually detect
things in that atmosphere that might be signs of life or clues that the planet is habitable.
We can detect water, CO, CO2, methane.
You can ask fascinating questions like,
what created that methane?
Could it be life?
If we want to look for a planet that's similar to Earth,
we would probably want to go out and look for CO2 first.
It might sound small, like, oh, analyzing the atmospheres
of different planets, but really,
this is going to be our first step to that ultimate question of,
is there life out there?
Is there another Earth-like world?
Is there a place that we could live on or something to live on?
There's most certainly life out there.
The universe is large.
The galaxy is large.
There's billions and billions of planets out there.
Life has to form.
We've seen it form in the strangest places here on Earth, right?
The question is, will we know that we're seeing life when we make that measurement?
There are just so, so many exoplanets.
And we just don't know what's possible on these worlds.
And the web is giving us this opportunity to really deeply investigate them for the first time,
to fill in the coloring book of the planets of the galaxy.
It's a very complicated universe.
I want to know where we fit into it all.
Are we alone?
And this kind of enormous ultimate problem
of are we alone in the universe
is just one of these huge questions that the web
can let scientists try and answer, right? Yeah, yeah. Exoplanets are a huge source of unknowns,
but there are other huge areas of unknowns too. Areas that have less to do with traveling through
space and more to do with actually seeing back in time. What do you mean?
The farther away we look with a telescope,
we see older and older light.
That light has just taken a really long time to get to us.
And we can take these snapshots of a universe like long past,
like as it existed billions and billions of years ago.
So I want to tell you about this next week.
Okay.
Scientists who are trying to look back further than they have before,
they actually want to point this telescope at a blank region in the sky that looks like there's nothing there.
They're hoping to find the very first light of the universe. How far will it come?
And still has to go.
How far will it come?
Each one tells us.
How far will it come?
This episode was reported by Brian Resnick and produced by me, Meredith Hodnot.
Noam Hassenfeld wrote the music and edited the episode with help from Jillian Weinberger.
Mandy Nguyen checked the facts.
Christian Ayala was on mixing and sound design. And unsurprisingly, Bird Pinkerton wrote an awesome article about Formula One for Vox this week,
so you should totally check that out.
Lauren Katz heads up our newsletter
and Liz Kelly Nelson is the VP of Vox Audio.
You can sign up for our newsletter at vox.com slash unexplainable
and email any thoughts you might have about the show
to unexplainable at box.com. Thank you.