Read the full transcript of Astrophysicist Amber Straughn’s talk titled “What Space Telescopes Teach Us About The Universe” at TEDxCapeMay 2025 conference.
Listen to the audio version here:
TRANSCRIPT:
A Childhood Fascination with the Stars
AMBER STRAUGHN: So imagine for a moment that you’re on my family’s farm in rural Arkansas. It’s a beautiful summer night. You can hear the crickets, and you can smell the honeysuckle, and the sky is filled with thousands of stars. Those stars called my name as a kid, and I spent countless nights outside looking up and asking some of the same questions that humans have been asking for millennia.
Where did we come from? How did we get here? Are we alone? A dark night sky full of stars has always been an open invitation to ask big questions.
Across languages, across time, across culture, the universe invites us to look up and to wonder. I was really fortunate as a kid that I had parents that supported my curiosity. I distinctly remember one time I asked my mom some outlandish question, and she looked at me and she said, “I don’t know the answer to that, but someday you can figure it out.” That gave me the courage to start to follow my dreams.
From Hubble to James Webb: A Journey Through Space Telescopes
Today I’m an astrophysicist at NASA’s Goddard Space Flight Center in Maryland. When I was in the fifth grade, NASA launched the Hubble Space Telescope, and I was hooked. Those beautiful images of stars and galaxies really spoke to my soul.
And Hubble has been in space now for over three decades and is still incredibly productive. And it certainly paved the way for what was to come next. The James Webb Space Telescope is by far the biggest and most complex telescope that we’ve ever sent to space. Telescopes like these take decades of focus.
The iconic gold mirrors were one of the first technologies we started working on over 20 years ago. This giant mirror is polished so smoothly that if you stretched it out to be the size of the continental U.S., the biggest mountain would only be a few inches high. The telescope has a giant sunshield the size of a tennis court that basically serves to protect the mirrors from the heat and the light of the sun.
It’s basically a giant beach umbrella, and it provides an SPF of about a million. Decades of work on something that’s never been done before. I don’t have to tell you that this was difficult. It was impossible when we got started.
We had to invent 10 new technologies just to get started building the telescope. And we had engineering difficulties along the way. We had problems with our detectors. We had problems with the sunshield, with the electronics. We had over 300 single point failures.
Individual things that had to go perfectly or the telescope would fail. And we would be too far away to go and fix it.
The Launch: A Moment of Celebration and Anxiety
Before launch, people used to ask me, are you scared? And I knew that our brilliant engineers had done everything they could to ensure mission success.
But still, 300 single point failures. I was terrified. And then on Christmas Day 2021, we launched into space. I was originally supposed to watch the launch or work the launch from the mission ops center.
But as it started to slip into the holidays, I decided, along with several others, to work the launch remotely. And a lot of us have been working remotely for a long time. It’s still incredible to me that the two years leading up to launch were done during a global pandemic.
So in a true full circle moment for me, I worked the launch from my mom’s couch in Arkansas. This incredible video shows real footage of the telescope separating from the rocket shortly after launch. In this view, you’re seeing the bottom of the folded up telescope. You can see little bits of ice floating off and of course the beautiful earth in the background.
Launch was a moment of true celebration for our team.
But remember what I said about all those single point failures? We had six months of intense work to unfold the telescope and to get it into working order before we released the science images to the world. It all went perfectly.
And then in July of 2022, we released those images to the world for the first time. Using some of these new images, I want to tell you a cosmic story. Our collective cosmic story, starting with our backyard of the solar system.
Exploring Our Cosmic Backyard
How many of you have seen Saturn through a telescope? It’s memorable, right? The first time I saw Saturn through a telescope, I thought it looked fake. Almost like somebody was holding out a cardboard cutout at the end of the telescope. This view of Saturn from JWST shows us a whole new view of the ringed planet. JWST sees the universe in infrared light that’s completely invisible to our eyes. Infrared light is light that’s a little bit more red than what your eyes can see.
In this view, the methane gas on the planet’s atmosphere is absorbing a lot of the infrared sunlight that hits it, whereas the icy rings are reflecting it. And of course, in addition to planets in our own solar system, we now know that there are planets orbiting other stars outside of our solar system, what we call exoplanets. JWST is allowing us to start to look at the chemical signatures in the atmospheres of these planets orbiting other stars in a way that’s never been possible before.
The Pillars of Creation: A Cosmic Time Machine
Another one of my favorite images is the Pillars of Creation. Here we see stars being born out of gas and dust. To set the scale for this image, every point of light that you see here is a star like our sun.
The Pillars of Creation lie about 6,500 light years away. That means that the light that we’re seeing has been traveling through space for 6,500 years until it got to our telescope.
In this sense, telescopes are time machines. They literally allow us to see into the past. And that’s due to the simple nature of the way light travels through space. It takes time to travel.
So light from the sun takes about eight minutes to reach the earth.
So in essence, we’re seeing the sun as it was eight minutes ago. You can think about stepping out to objects that are further and further away, and we’re seeing them as they were in the distant past. This gives us an incredible ability to study the universe. The Pillars of Creation still lie within our Milky Way galaxy.
Galaxies: Our Cosmic Neighborhoods
Now I want to step a little further out and show you another galaxy.
So first to take you back to middle school science class for a moment, a galaxy is just a collection of stars held together by gravity. If you go outside tonight, look up at the stars, all the stars you’ll see in the nighttime sky are part of our home galaxy of the Milky Way. This galaxy is similar to our Milky Way in that it’s a spiral galaxy defined by its shape. In the center here, the bluish light is showing us an older population of stars, whereas new stars and gas and dust are radiating out in spiral arms from the center.
The Hubble view of the same galaxy in the lower right shows us immediately why having different types of telescopes in space is so important. Hubble sees the universe in visible light like your eyes see, whereas JWST sees in infrared light.
And having these different types of light helps us to put together a more complete picture of how the universe works. These telescopes have shown us that the universe is filled with galaxies. This is one of my personally favorite images because this is part of a project that I work on myself. I study how stars and black holes form in distant galaxies, and these deep fields of the universe are helping us learn about those processes.
And again, scale is always important in astronomy. In this image, we’re looking through and past our Milky Way galaxy to the deep, distant universe. Almost every point of light that we see here is not a star, but an individual galaxy itself filled with hundreds of billions of stars.
And in this view, we see 10,000 galaxies.
And so you might think, okay, it’s a big picture of the sky, right?
But no. If you hold out your pinky finger at arm’s distance, you can cover up this tiny patch of sky, 10,000 galaxies under your pinky. Images like this have shown us that the universe is filled with hundreds of billions, perhaps a trillion, other galaxies. These deep field images from JWST are doing exactly what they were meant to do.
They’re allowing us to look back in time over 13 and a half billion years into the past to help us learn how it all got started. And what we’re finding is incredible and a little puzzling. We’re finding many more of these early galaxies than we expected, and they seem to be bigger than our theories predicted, and their black holes are growing faster than we expected.
And we don’t yet understand why. It’s a really exciting place to be in science. In this view, we’ve zoomed way out, far back.
The Cosmic Cliffs: Beauty in the Universe
Now I want to take you back a little bit closer to home, back within our own Milky Way galaxy.
So before launch, when people used to ask me what my favorite image was, I would usually point to a deep field like this, but not anymore. These are the cosmic cliffs of the Carina Nebula. Here we see over 100 new stars for the very first time. Near the top of the image, hot, young stars are giving off massive amounts of radiation and carving out the beautiful vista below.
And it is beautiful, right?
But why? Why do we find these images beautiful? It’s a bit strange, actually. It’s completely normal that we would find images of sunsets or oceans or mountains beautiful.
Those things are part of our experience as humans, but nebulae and galaxies aren’t. Why is it we find these images beautiful? I don’t think I know the answer to that, but I wonder if it might be that on some deep level we realize when we look out at the universe, we’re looking back at ourselves, back at our origins. Something about this feels like home.
The Dark Universe: What We Don’t Know
Of all the astounding things that we’ve learned from JWST over the past few years, there’s still something incredible. Everything that we can see and measure, all the hundreds of billions of galaxies, trillions of stars, countless planets, all of that stuff only makes up 5% of the universe. The rest, the other 95%, we have no idea. Of this 95%, we think about 5% is normal matter, 25% about is what we call dark matter, and a little over two-thirds is dark energy.
So first, dark matter. Dark matter is like normal matter in that it has mass and takes up space, but we only know it exists because we can see its effect on other objects. We’ve never seen it directly, and it doesn’t seem to interact with light or itself or anything else. It’s weird.
It might be some subatomic particle that we haven’t identified yet, but we don’t really know. If you think dark matter is strange, let me tell you about dark energy. We’ve known for a long time, almost 100 years now, that the universe is expanding, but in the late 90s, we learned something truly unexpected. The universe is expanding faster and faster all the time.
It’s accelerating in its expansion. This was something that we never dreamed of, and we call this property of the universe dark energy, and you guessed it, we have no idea what’s causing it. We have some theories as to what it might be. We think it’s probably intrinsic to space itself, but really, it’s one of the biggest mysteries in science overall.
The Future of Space Exploration
So there you have it. Almost all of everything that is, and we don’t know what it is, but we’re building a telescope to help us find out. The Nancy Grace Roman Telescope, NASA’s first astrophysics mission named after a woman, is being built right now, and one of its primary goals is to help us unravel the dark universe. It’ll launch in early 2027.
Another one of our cosmic unknowns is a question that’s central to our very existence as human beings. Are we alone? Right now at NASA, we’re developing the technologies that will ultimately enable a telescope that’s specifically designed to find life on an Earth-like planet. We’re calling it the Habitable Worlds Observatory.
These telescopes are not just for me and my astronomer friends. They’re yours too. In a very real sense, if you’re a taxpayer in the US, Canada, or Europe, they are very much yours. You made them possible.
But even beyond that, anyone in the world can go and download these images and data and use them. These telescopes belong to all of us. We’re in a difficult time on our planet right now. I believe that these telescopes give us more than just answers to science questions.
They help us think outside of ourselves. They remind us of the beauty of the universe. And they show us our connectedness of me to you and you to me. We’ve got each other.
We’re not in this alone. And that gives us reason to hope. Hope that any little girl or little boy can achieve their dreams with the support of their family and community. The cosmic hope that if we live our lives with awe-filled wonder and curiosity, and if we put our hearts and our minds together to work for something good, that we truly can achieve the impossible.
It’s worth it.
Can you imagine learning the answers to all of these questions? Finding out what the 95% is? Finding out if life exists in the universe? Don’t you want to know?
