The Science Goals of the James Webb Space Telescope
Our James Webb Space Telescope is an epic mission that will give us a window into the early universe, allowing us to see the time period during which the first stars and galaxies formed. Webb will not only change what we know, but also how we think about the night sky and our place in the cosmos. Want to learn more? Join two of our scientists as they talk about what the James Webb Telescope is, why it is being built and what it will help us learn about the universe…
First, meet Dr. Amber Straughn. She grew up in a small farming town in Arkansas, where her fascination with astronomy began under beautifully dark, rural skies. After finishing a PhD in Physics, she came to NASA Goddard to study galaxies using data from our Hubble Space Telescope. In addition to research, Amber’s role with the Webb project’s science team involves working with Communications and Outreach activities. She is looking forward to using data from Webb in her research on galaxy formation and evolution.
We also talked with Dr. John Mather, the Senior Project Scientist for Webb, who leads our science team. He won a Nobel Prize in 2006 for confirming the Big Bang theory with extreme precision via a mission called the Cosmic Background Explorer (COBE) mission. John was the Principal Investigator (PI) of the Far IR Absolute Spectrophotometer (FIRAS) instrument on COBE. He’s an expert on cosmology, and infrared astronomy and instrumentation.
Now, let’s get to the science of Webb!
Dr. Amber Straughn: The James Webb Space Telescope at its core is designed to answer some of the biggest questions we have in astronomy today. And these are questions that go beyond just being science questions; they are questions that really get to the heart of who we are as human beings; questions like where do we come from? How did we get here? And, of course, the big one – are we alone?
To answer the biggest questions in astronomy today we really need a very big telescope. And the James Webb Space Telescope is the biggest telescope we’ve ever attempted to send into space. It sets us up with some really big engineering challenges.
Dr. John Mather: One of the wonderful challenges about astronomy is that we have to imagine something so we can go look for it. But nature has a way of being even more creative than we are, so we have always been surprised by what we see in the sky. That’s why building a telescope has always been interesting. Every time we build a better one, we see something we never imagined was out there. That’s been going on for centuries. This is the next step in that great series, of bigger and better and more powerful telescopes that surely will surprise us in some way that I can’t tell you.
It has never been done before, building a big telescope that will unfold in space. We knew we needed something that was bigger than the rocket to achieve the scientific discoveries that we wanted to make. We had to invent a new way to make the mirrors, a way to focus it out in outer space, several new kinds of infrared detectors, and we had to invent the big unfolding umbrella we call the sunshield.
Amber: One of Webb’s goals is to detect the very first stars and galaxies that were born in the very early universe. This is a part of the universe that we haven’t seen at all yet. We don’t know what’s there, so the telescope in a sense is going to open up this brand-new part of the universe, the part of the universe that got everything started.
John: The first stars and galaxies are really the big mystery for us. We don’t know how that happened. We don’t know when it happened. We don’t know what those stars were like. We have a pretty good idea that they were very much larger than the sun and that they would burn out in a tremendous burst of glory in just a few million years.
Amber: We also want to watch how galaxies grow and change over time. We have questions like how galaxies merge, how black holes form and how gas inflows and outflows affect galaxy evolution. But we’re really missing a key piece of the puzzle, which is how galaxies got their start.
John: Astronomy is one of the most observationally based sciences we’ve ever had. Everything we know about the sky has been a surprise. The ancients knew about the stars, but they didn’t know they were far away. They didn’t know they were like the Sun. Eventually we found that our own galaxy is one of hundreds of billions of galaxies and that the Universe is actually very old, but not infinitely old. So that was a big surprise too. Einstein thought, of course the Universe must have an infinite age, without a starting point. Well, he was wrong! Our intuition has just been wrong almost all the time. We’re pretty confident that we don’t know what we’re going to find.
Amber: As an astronomer one of the most exciting things about working on a telescope like this is the prospect of what it will tell us that we haven’t even thought of yet. We have all these really detailed science questions that we’ll ask, that we know to ask, and that we’ll answer. And in a sense that is what science is all about… in answering the questions we come up with more questions. There’s this almost infinite supply of questions, of things that we have to learn. So that’s why we build telescopes to get to this fundamental part of who we are as human beings. We’re explorers, and we want to learn about what our Universe is like.
Webb will be the world’s premier space science observatory. It will solve mysteries in our solar system, look beyond to distant worlds around other stars and probe the mysterious structures and origins of our universe – including our place in it. Webb is an international project we’re leading with our partners, ESA (European Space Agency) and the Canadian Space Agency.
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