Keegan Leibrock
Welcome to Longitude Sound Bytes, where we bring innovative insights from around the world directly to you.

As part of our series focusing on the James Webb Space Telescope, our conversations aim to shed light on the contributions of people from various organizations that brought it to fruition.

I am Keegan Leibrock, a student at Rice University pursing degrees in economics and political science.

For this episode, I had an opportunity to speak with Dr. Matthew Greenhouse, an infrared astronomer from NASA. He has been working on the Webb telescope since 1997.

Prior to 1997, Dr. Greenhouse worked for the Smithsonian as an astrophysicist. We began our conversation about his work there and what it was like transitioning into working at NASA.

Please enjoy listening!

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Matthew Greenhouse
I’ll give you a little bit of my background. I got my undergraduate degree from the University of Arizona in Tucson. My undergraduate degree was in geology. I became a geologist. And then I decided that I wanted to go into planetary geology and then shortly after that, I decided I wanted to just go into astrophysics. And so, I went off to the University of Wyoming to get my PhD in astrophysics. I went to Wyoming because at the time, they had just built what was the world’s largest infrared telescope. They needed people to help build instrumentation and things like that. So, I thought it was a good place for me to go, and it turned out to be.

The first job that one gets after getting a PhD, it’s called a postdoctoral fellowship, or postdoc. And I did my postdoc at Smithsonian in Washington, where the primary project that I worked on was a European Space Agency project called the Infrared Space Observatory. Then, in 1996, I moved to Goddard Space Flight Center, because I’m the kind of astronomer that builds things and Goddard was just a better venue or place to be for building things than Smithsonian. In 1997, I joined the Webb mission, and I’ve been on that mission, ever since. It’s turned out to be my whole career.

Keegan
Honing in on the Webb Space Telescope, what sort of discoveries have been made using this new telescope? To me, it seems like new discoveries are being made every day, the capabilities are obviously immense. So, like, what is the processing like for these new discoveries?

Matthew
Well, Webb mission is just getting started. We’re a little over a year into the science mission. But as you say, every other day, there’s a there’s a discovery with the Webb. The Webb is giving humanity its first high-definition view of the infrared universe. So, it’s not a surprise that we’re having so many discoveries so quickly.  Much of it comes from the Webb’s ability to see fine detail like the Hubble Space Telescope does, and the Webb’s ability to detect incredibly faint light from the early universe and do all this in the infrared part of the spectrum. So, the Webb is showing us our first look at the first galaxies. A lot of surprises there. It’s enabling us to measure the chemistry in exoplanet atmospheres and all kinds of objects, revealing some phenomena that have never been seen before. It’s very exciting.

One of the things that seem unique about the Webb mission that we haven’t seen in the past, is the extent to which all the exciting results from the Webb, show up on social media and are all over the world within days, if not hours. So, the Webb is I think the first mission of its kind to fly in the era of social media. And so, it’s enabling all of humanity, really, not just not just the people in the US and Europe to share in the excitement of the web mission. I think it’s wonderful.

Keegan
And with that, can you explain how the Webb Space Telescope is sort of different from past telescopes such as the Hubble Space Telescope, it’s like the infrared capabilities and like being able to see new things that were previously not available.

Matthew
Sure. The Webb is designed to operate in the infrared part of the spectrum and that is what is most different about it from some of our other observatories. Hubble operates in the ultraviolet, visible part of the spectrum. Chandra operates in the X-ray part of the spectrum. One observes different phenomenon in these different parts of the spectrum.

Everything we know about the universe outside our solar system comes to us transmitted in starlight. What modern astronomers do primarily is extract physics information from starlight. And so, to get all the information about the universe, we need all the star light. And so that requires that we put telescopes in space because much of the light is blocked by our atmosphere. And it also requires that we build a number of different observatories that can operate concurrently with each one focused on a different part of the electromagnetic spectrum. The spectrum of light. Because one needs different types of equipment and methods to observe in different parts of the spectrum. So, we require several different observatories.

We built the Webb as an infrared telescope, in order to see the light from the very first galaxies to form after the Big Bang. Galaxies emit most of their light in the ultraviolet part of the spectrum. But as that light travels to us, through the expanding space of the universe, for these primeval galaxies, the wavelength of the light is stretched into the infrared by the expansion of space. So, to observe it today, we have to build an infrared telescope. And that comes with all kinds of technical problems and unique challenges but it’s one of the things that sets the Webb most apart from, say, the Hubble. The Hubble cannot see the first galaxies, because it doesn’t have sufficient infrared capability. Also, its primary mirror is too small to be able to detect the faint light from those first galaxies.

Keegan
What is the role of NASA and sort of coordinating different partnerships with other organizations as well as like funding for Webb Space Telescope projects?

Matthew
Well, the Webb project was much too large a project for NASA to do by itself. So, it was a partnership with the European Space Agency and also the Canadian Space Agency. You know, we had to invite those agencies to be partners, and then we had to negotiate those partnerships.

Keegan
And with that, what sort of ongoing projects are there currently, regarding the telescope? And I was also curious, like how use of the telescope may be divided, because I’m sure a lot of different astronomers want to use it.

Matthew
How does it all work? Well, once a year, NASA solicits observing proposals. Proposals on where to point the telescope, from the worldwide astronomical community. Not anyone can submit such a proposal. Then the proposals are peer reviewed. They’re reviewed by other astronomers in a double-blind fashion. Then a subset of all those proposals are selected to be uploaded to the Webb telescope. That’s how it works. So, after each one of those proposal cycles, we have about a year’s worth of observing projects queued up.

Keegan
So is that a pretty competitive procedure? Are there people who maybe don’t get to go through their projects for some time?

Matthew
Yeah, it’s an enormously competitive procedure. Each proposal is typically authored by a large team of astronomers. It’s very competitive but it’s also very fair. The double-blind aspect makes it possible for very young astronomers and basically anyone with a good idea to get that idea evaluated on a level playing field.

Keegan
Awesome, and what does your day-to-day work look like with regard to the Webb Space Telescope and other NASA projects? I’m sure you have all sorts of things going on.

Matthew
Right now, my focus is actually on missions that are in development now that haven’t flown yet. So, my Webb work is basically finished. It’s up and flying and working great. So, we have occasional anomaly resolutions and things like that but my focus is on very much on what comes next in the infrared.

Keegan
Yeah, and building on infrared I know you discussed this earlier but what specifically can the Webb telescope offer into the origins of life into the universe that previous telescopes couldn’t? I know you said, they can see further into the origins?

Matthew
Yeah, when I was a graduate student, there were no planets known outside our solar system. Today, we’ve identified more than five thousand, with the implication that all stars have planets. I mean, most astronomers would agree that all stars have planets with very few exceptions. And that gives us the implication that there are billions of habitable worlds in our galaxy. We don’t know that they’re inhabited but we know that they’re habitable. And we have learned how to search for life on them by studying the chemistry of their atmospheres. With missions like the Webb and even Hubble, we have developed techniques for doing spectroscopy on exoplanet atmospheres. Spectroscopy is a process by which we spread light out into its component colors, with special optics to allow us to see the emission and absorption of light by individual atoms and molecules in the atmospheres of these exoplanets. And what we’re looking for is chemistry that would be indicative of life. Chemistry that would be hard to explain with a biotic processes alone. And this is really just getting underway at NASA. The search for life is no longer a stuff of science fiction, it is very much a major objective of NASA Space Science. And we’re well into it now. So, the Webb will be the first major strategic mission to really work on this hard, and many more will follow.

Keegan
Sure, and with that, how do you think how else do you think the telescope will continue to shape the field of astronomy moving forward?

Matthew
It’s raising lots of questions about how galaxies form and evolve. It’s going to show us star formation in our own galaxy in detail that we’ve never seen before. It’s shown us unusual phenomena that we’ve never seen before. We have seen how, in one particular example, a late type star is seen to periodically emit pulses of dust formation that have produced an incredible display of a concentric rings of emission around the star. The Webb is just a fantastic machine, one that we’ve never had anything like it before. Whenever we take an image with the Webb, the background of the image is in effect, a deep field image like the Hubble deep field image. So the data is just incredibly rich. The system’s working perfectly. And we’re all very excited. And it should be just continuous excitement for as long as the Webb lasts.

Keegan
How long is the lifecycle typically of a telescope like this? Obviously, there has never been one like the Webb Space Telescope, but do you anticipate that 20 years down the line, maybe 30 years, there’ll be an even bigger telescope developed?

Matthew
Well, there definitely will be. The formal engineering life of the Webb is five years. But the consumables on board are, we have apparently 20 years of fuel. And that doesn’t mean the Webb will last 20 years, but it can last that long. If it doesn’t last that long, it won’t be due to lack of propellant. So, we’ll have to wait and see. Hubble of course, has lasted way, way, way beyond this design life, but by virtue of servicing. The Webb cannot be serviced the way Hubble was. The astronauts can’t go to the Sun-Earth L2 point where the Webb resides. We built lots and lots of redundancy into the Webb adjustability and we’ve designed it for graceful degradation. So, we’re very optimistic that it’s going to last a long, long time.

Now, the successor mission to the Webb, the one that NASA will launch right after it, in 2027, is called the Roman Space Telescope. It’s a completely different machine that’s designed primarily to study dark energy. But one of the things on board the Roman Space Telescope is a technology development instrument that will prove out the technology that we need to observe Earth like exoplanets. And ahead of the true successor to the Hubble Space Telescope, which is something called the Habitable Worlds Observer, the National Academy of Sciences last year gave NASA permission to go off and work on this Habitable Worlds Observer mission as their highest priority for the next mission, and it will be an optical UV telescope, like Hubble, only of size similar to the Webb. That’ll be the next thing up after the Romans Space Telescope, in the very large category of things. It should really, really be able to make a way on exoplanets as small as the Earth and really extend the Hubble UV optical science into the future.

Keegan
So are these projects deep into development? Are they being made? Are they in the approval process?

Matthew
Well, on the Roman Space Telescope is close to launch. So, it’s very much being built now. The Habitable Worlds Observatory is just starting in the planning process, and it will launch most likely toward the end of the 2030s.

Keegan
And as one final question, what advice you would have for those students seeking a career in astrophysics or related fields?

Matthew
Oh, well, that’s easy. If you want to work, well, first of all, the people that work in this field come from all walks of life, from all backgrounds. And a great way to… to work in this field, go to college, study whatever you love. But if that happens to include science, engineering, and math, then working in this aspect of aerospace is a very, very realistic career objective. You don’t need to be anyone special. You don’t have to have any special genius. You just need to be willing to work hard and be enthusiastic about it. And one way to test the waters is to do an internship at NASA. NASA has internships for every level from a high school to senior faculty. And if you’d like to work on data from missions like the Webb, but you don’t want to become a scientist, you can do that, too. NASA has a program called Citizen Science. And if you go to the Citizen Science website, there are all kinds of projects that you can get involved with just by being an interested person. And that’s another way to sort of see what it’s like and rub elbows with the folks who do this for a living.

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Keegan
We hope you enjoyed our episode. Please visit Longitude [dot] site for the transcript.

If you are a college student interested in leading conversations like this for our next podcast, please write to us at podcast@longitude.site.

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