University of California, Santa Cruz astronomer Garth Ellingworth, deputy director of the Space Telescope Science Institute, has been through the hell of his career.
He has devoted decades to the quest to find and understand the most distant galaxies, and was a leader on the team that built the Hubble Space Telescope. And before Hubble was in the sky, it had already begun developing the James Webb Space Telescope (JWST) – yes, who – which James Webb Space Telescope, which currently excites the minds of Earthlings daily with very beautiful images of our universe.
While most of us look at these JWST photos and only see the photos, Illingworth and his peers see all that and more: the data. Over the course of the few months of work, Webb has already provided a luminous body of information — results that have confirmed, confounded, and even contradicted existing theories about the universe. Curious about what this data means for ourselves, we caught up with Ellingworth to talk about space telescopes, distant worlds, and the ever-evolving scientific process.
This interview has been edited and condensed for length and clarity.
Future: Your work has been extensive. Can you tell us a little bit about your research and where it took you?
Garth Ellingworth: Sure, I will give you the scientific framework. I’m an astronomer, and my main interests were the early galaxies in the universe. Basically, we live 13.8 billion years after the Big Bang in a wonderful spiral galaxy, the Milky Way. But we had to get to that point.
Beginnings have intrigued me for a long time, ever since I saw the Hubble Deep Field in 1995 – the first deep Hubble image of an empty part of the sky, which turned out not to be empty, but completely full of galaxies. This is what I’ve been working on for 25 years or so. In fact, in the ’80s, when I started thinking about Webb, we hadn’t really launched Hubble. Riccardo Giacconi, director of the Space Telescope Science Institute, told me at the time, “You guys really need to work on the next big telescope. Believe me, it’s going to take a long time.”
We had to do something very interesting at that point. We had to move forward, even when we didn’t know what Hubble would discover. We realized that we should go to longer wavelengths, we should really go in the infrared – we felt that there were many ways in which it could reveal aspects of the universe that Hubble would never reveal. It must be a large telescope to work in infrared. It must have been really cold, which meant it had to go a long way from here. When we look at the graphics now, these graphics are very simple, they are very different from Webb, but actually Webb works and has the characteristics that we thought of at the time. It’s a big telescope, it’s infrared, it’s really cold, it’s a hell of a long way from us [laughs].
Correct me if I’m wrong, but you and your team discovered what is believed to be the most distant and oldest galaxy that humans have seen so far, dating back about 400 million years after the Big Bang.
yes. So, about seven or eight years ago, using Hubble, we amazingly found something that was about 400 million, 450 million years after the Big Bang. I guess if you asked me 10 years ago if Hubble would do that, I wouldn’t have said any way. But it turns out that at the limits of the Hubble telescope we managed to find this early galaxy, and we can already see it with the Spitzer Space Telescope – we can show that there is a mysterious point there. This has been a real mystery for about seven years. We couldn’t learn much about it, but it did point to an interesting change in the way galaxies formed in early times. So the moment Webb started working, the big question was: Is this object unique? Or are there many others like this?
Within four days of Webb’s data release in early to mid-July, we already had a paper sent to a prepress server. In fact, there were two groups doing this on the same day, saying that we spotted two other beings like that, and one of them was far away. This was the step we hoped Webb would take – that it would expand our horizons to earlier times, and he did it surprisingly quickly and very well.
I think this goes back to the point of working on getting Hubble into space, but I’m already thinking about the next thing. Now, James Webb seems to be happening very quickly – but that’s because there is such a great scientific basis already.
Yes, exactly. In the late 1990s, after the emergence of the Hubble Deep Field, finding the first galaxies became Webb’s central goal. But at that time, we discovered the first exoplanets. Under discussion were dark energy, dark matter. There were a lot of things Hubble discovered that we knew Webb would make a difference – we ended up waiting 23 years.
In July, when the first pictures were posted, we had an hour where we were all seeing them for the first time. I was sitting in the same room at the Space Telescope where we had our first meeting in 33 years. It was a little weird to sit there, looking around at God, this room looks pretty much the same as it did when we first talked about Webb, and now we see the first pictures coming in. She is so amazing.
One particularly interesting takeaway from James Webb is that some of the new data appears to contradict previous findings. Can you tell us more about that early galaxy that was much larger than previously expected?
Yes, of course. So this one, which we called GNZ11 – not a very fancy name, but astronomers are pretty boring when it comes to naming things. [laughs] – He pointed out something unusual in these very early times.
So in the first four days after publishing the web images, we wrote these papers, and we realized that GNZ11 wasn’t unique – there were others from these very bright and very luminous galaxies, which we interpreted as unusually massive. Then, within weeks, there was another event in the past, akin to the Big Bang, which was still incredibly massive. It was really a surprise. We have to ask ourselves: is it really huge? Or does it contain really unusual stars that are very bright, but not very massive? We don’t know at this point, but Webb can answer these questions.
What we need to do now is go in and look at those things in more detail, and see if we can learn more about what’s really out there in that galaxy. What do the stars look like, are there so many small stars that contribute a large mass. Now theorists are wondering: How can you build a galaxy like this so fast, and have a black hole forming so fast there too? Were we cheated? Galaxies can be very challenging. The universe can play games with you, even when you have web quality data, but you don’t have enough of it.
What do you think a situation like this would say about the scientific process itself?
This is interesting, because I would say that in the past there was a very slow process of doing things. The data didn’t come in very quickly. We spent a lot of time working with him, and sometimes you have to go back and get more. Then, you know, the papers will come out, and we’ll be very critical. Leaves come out, everyone thinks “Oh, that’s cool.” Then a year later, some new data came out saying “well, that was a bug”. You have to realize that you can be wrong at any time, but when you are wrong, you learn new things.
I guess I never really felt particularly bad if people cared to do the best they could at the time, and then go back and review things. Being wrong isn’t bad, it’s part of the process. It is probably inevitable at this point.
Webb was busy. Is there an upcoming goal on their list that you are particularly excited to see and learn more about?
Yes, the big picture that was originally shown, of the galaxy cluster, which indicated what I think will be very valuable in the future to learn more about galaxies. But I don’t just want to stress distant galaxies – exoplanets would be amazing, and then of course star-forming regions like the Carina and the Tarantula Nebula. These look cool, but there’s an incredible amount of science in those as well.
And I would just say, you know, when I was sitting there watching the first pictures, I was amazed by their beauty and personality there, the info. But one of the things I was thinking about then was: In that hour, I saw, like, six sets of data. I must say, this is more data than I have ever seen of any kind in any reasonable amount of time in my entire life. Scientists will be working on those alone for ages, because there is a lot of information in those. And this was just an explorer — I mean, that was dozens of hours of time, so we’re going to multiply that by 100, 1,000 times every year.
One of the things that is often asked: Why is this important? It’s a lot of money. I’ve thought a lot about this, and I think the human race has a deep interest in our origins. We are interested in how we appeared and how life arose. Then you go really, well, we’re sitting on this little planet, how do the planets form? You can take that origins question, and that’s what astronomy is really about. Webb, Hubble, these things are just genesis machines. And what I really love about this, in many ways, is that we live in a very divided environment, and this interest intersects with a lot of these and other political areas beautifully.
It’s one of those places where we still have some common interests – which I hope we can expand in the future! Webb should at least contribute to this.
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