Thirty Years Of Stardom

IRA FLATOW: This is Science Friday. I’m Ira Flatow. Think about the breathtaking images you’ve seen of space– swirling, multicolored galaxies, shining star clusters, far-off planets. There’s a good chance these photos were taken by the Hubble Space Telescope. Hubble has helped us better understand space mysteries, like black holes, warped space, exoplanets, and the expansion of the universe.

30 years ago today, Hubble was launched into space. And through multiple repair jobs right from its very beginning, it’s the orbiting observatory that just keeps on going. To celebrate this anniversary, we’re joined today by Dr. Jennifer Wiseman, senior project scientist for the Hubble Space Telescope in Greenbelt, Maryland. Welcome to Science Friday.

JENNIFER WISEMAN: Thank you.

IRA FLATOW: Do you remember the beginnings of Hubble when it was launched in 1990? You were studying to become an astrophysicist, right? It must have been exciting times.

JENNIFER WISEMAN: Oh, it was exciting. I was studying for a graduate degree in astronomy up at the Harvard Smithsonian Center for Astrophysics. And we were all very excited about this new idea of having a telescope on a space-based platform. So it would be above the Earth’s atmosphere and would provide much clearer views of deep space. We were in high anticipation.

IRA FLATOW: Tell me what the anticipation was like. What were you expecting to get out of this new telescope?

JENNIFER WISEMAN: Well, we weren’t sure, actually. We were excited because we didn’t know exactly what it would bring us. We just knew it would bring us more, better information, perhaps even change the kinds of questions we’d be asking about the universe.

Now, I myself was studying a different kind of astronomy. I was using radio telescopes, the big dish kinds of telescopes that collect low-energy radiation from regions where stars are forming. But all of us, no matter what kinds of astronomy we were specializing in, were really excited about this new that was going to open up vistas and new questions.

We were particularly interested in what the telescope would tell us about deep space, very distant, faint galaxies that had been impossible, really, to see up to that point. But we were also curious about what it would tell us about our own solar system and nearby star systems as well.

IRA FLATOW: You know, to me, Hubble is one of NASA’s greatest triumphs because it brought outer space closer to everybody here at home. And some of the images– virtually all of the images– were just fantastic things we had never seen before. Do you have a favorite Hubble achievement or discovery or an image?

JENNIFER WISEMAN: I have many favorites. That’s like asking someone which child is your favorite. But I think the one that actually always stirs my soul when I look at it is something we call the Ultra-Deep Field. Now, this is an image that was taken by pointing the Hubble Space Telescope in a direction of the sky where there aren’t many nearby stars to drown out the image and just collecting light for many days so that the faintest objects would show up in the resulting image.

This resulting image is basically a collection of thousands of galaxies, these smudges of light that when you look at them you see spirals. You see sphericals. You see all kinds of galaxies in this tiny little field in the sky and realize that our universe is magnificent. It’s enormous.

If you can extrapolate in your mind that image over the whole sky, you realize visually what it means when we say there are hundreds of billions of galaxies in our observable universe. And I like to imagine being able to suddenly blink my eyes and travel to any one of those galaxies and look around. If we were that far away looking back, our own Milky Way would look like one of those spiral smudges of light.

And then, of course, some of those galaxies are more distant than others. So one of the big challenges of astronomy is to measure distances to different things in space. And astronomers have very carefully been mapping out the distances to these various galaxies and finding out how the universe has changed over time because, of course, we’re looking at these galaxies as they were when the light left them to begin its journey across vast distances of space to get to our telescope.

And so some of these galaxies are millions of light years– a light year is the distance that light travels in one year. Some of these galaxies are shining to us for millions of years in the distant past. And some are shining from billions of years, really toward the very beginning of our universe when galaxies were first starting to form.

So we can compare those very distant galaxies and the way they look and their compose– their nature with galaxies like our own and really see how the universe has changed over time. And that, to me, is fascinating.

IRA FLATOW: The idea of putting a telescope in space– an observatory in space, I guess, offers advantages over having one on the ground here.

JENNIFER WISEMAN: Of course. So the whole idea of putting this telescope in orbit around the Earth is not to get it closer to the things we’re observing, but to get it above the Earth’s atmosphere. It’s only about 340 miles above the surface of the Earth. But it’s high enough to get it above most of our atmosphere and above the clouds. And we can get much sharper images.

Light coming through the turbulent atmosphere of Earth can get blurred. And also, our atmosphere actually filters out some types of light that we would like to receive for astronomy. That’s good for us. The ultraviolet light cannot get through the atmosphere, and that’s helpful for our health.

But we want to see ultraviolet light in astronomy. A lot of objects in deep space emit interesting radiation in the ultraviolet range of light. And Hubble can see that above the Earth’s atmosphere. So that’s what’s been the transformational change that we’ve had with the Hubble Space Telescope and subsequent space telescopes.

IRA FLATOW: What are the questions that Hubble is still investigating now?

JENNIFER WISEMAN: Well, that’s a great question because some of the questions that Hubble was originally tasked to address are still being investigated. One of those is, for example, the expansion rate of the universe. The namesake of Hubble, Edwin Hubble, helped us understand that the universe itself is expanding. Space itself is stretching.

But what is the rate of that expansion? And how long has this been going on? How old is the universe? That was one of the original goals of Hubble. And Hubble did, in fact, refine our understanding of that expansion rate of the universe. And we’re still measuring that and refining that with Hubble to this day.

In fact, Hubble helped provide us with a surprise, along with some telescopes on the ground, when it deduced that in the last few billion years that expansion rate of the universe has been increasing. The expansion is accelerating. We didn’t expect that because matter tends to pull things together, not push things apart. But there’s something we call “dark energy” accelerating that push of the universe’s expansion. So that’s something we’re still studying with Hubble.

And we are also doing things with Hubble now that we didn’t anticipate or even imagine when Hubble was designed, such as studying exoplanets. These are planets not in our own solar system, but planets orbiting stars outside of our solar system. These exoplanets were not known when I was starting graduate school. But now we know of thousands of these systems because our technology has improved.

They are generally detected by other kinds of telescopes, telescopes on the ground and space telescopes like NASA’s Kepler and test observatories. But then Hubble is the pioneer at studying the composition of the atmospheres of some of these exoplanets.

And right now we’re using Hubble to look at many of these exoplanets to discern what’s in their atmospheres. And we’re finding even water vapor in some of them. So these are early steps toward really understanding what other star systems are like. Those are just a couple of examples of what we’re using Hubble for these days.

IRA FLATOW: Speaking of exoplanets, there’s this story about a spooky exoplanet that Hubble found and now is not there anymore. It wasn’t what we thought it was. Explain that one.

JENNIFER WISEMAN: Oh, this is just a great story of how science is dynamic. We discover things. But when we keep studying them, we find out more and more. And this is a really intriguing exoplanet or what we thought was an exoplanet system around the star Fomalhaut. And Fomalhaut is a star that has a ring of debris around it. It’s always shown some evidence of having material, perhaps planets, orbiting that star.

But Fomalhaut B, which was, we thought, and might still think is one of these planets in the Fomalhaut system, was detected some years back with Hubble. It was observed in an image. And it’s very hard to image exoplanets because they’re generally very faint around other stars. We typically detect exoplanets in more indirect ways.

But this one we had an image from Hubble. And it’s a really beautiful and striking picture of an object orbiting a star, or so we thought. But over the years, a team of astronomers have been looking at the data and looking at more Hubble observations and seeing that this object seems to be fading over time, dissipating in a sense. It’s always been a little unusual because it didn’t shine as brightly in infrared light as we would have expected for a true exoplanet.

So this new team is hypothesizing that what we might be seeing is actually the result of the debris, if you will, of a collision in that system of two smaller planetesimals. And that dust cloud that was kicked up by that collision is what we were seeing. And it’s now dissipating over time.

And so that is a very cool finding. And of course, we’ll be looking at this system more and more just to see what’s happening and to further understand what’s happening in that other dynamic star system.

IRA FLATOW: A lot of technology has changed in the 30 years that Hubble’s been up there. Is Hubble still good enough for 2020?

JENNIFER WISEMAN: Well, this is the amazing thing. We’ve had Hubble for three decades now. And yet, truly, Hubble is more scientifically powerful and productive now than ever before in its mission. And we anticipate Hubble will keep giving us cutting-edge science for the next decade, maybe beyond.

The reason for this good news is at least twofold. One is that we’ve had a series of astronaut servicing missions over the years. You may remember the dramatic launch of Hubble, which was via the Space Shuttle back in 1990, and then its dramatic first servicing mission that corrected some errors in Hubble’s optics in 1993.

Since then, we’ve had wonderful vision with Hubble. And we’ve had several servicing missions with astronauts repairing equipment or putting in new and improved cameras and instruments on Hubble. That’s kept Hubble at the forefront of capability. So it’s like getting a new observatory every time.

The last time we did a Space Shuttle servicing mission was in 2009. And this mission was extremely successful. We had new refreshing batteries and gyroscopes. A couple of science instruments were repaired. And then we had two new science instruments installed. So we have a wonderful observatory now that’s still in fantastic technical shape.

And also, astronomers are using those instruments in the observatory in new, clever ways to get better and better science out of it. So because of that, we’re getting new and more interesting results, perhaps, than ever before. We’re getting more professional, peer-reviewed science papers out of Hubble than ever before. And we have a real positive sense of what we’re going to learn from Hubble in these coming years.

IRA FLATOW: I’m Ira Flatow, and this is Science Friday from WNYC Studios. Many more years do you think Hubble can operate for?

JENNIFER WISEMAN: Well, that’s the question of the hour. And that’s hard to give a firm prediction. NASA has committed to supporting Hubble as long as it’s being scientifically productive. And right now, it’s very productive. We are entertaining proposals from astronomers around the world every year. We think that the batteries and gyroscopes are in good shape.

And we have a real clever, wonderful team of engineers and technical experts on the ground here at NASA’s Goddard Space Flight Center and also at the Space Telescope Science Institute in Baltimore that are constantly monitoring these instruments and using them in the most productive ways. And from the rough predictions of looking at how healthy these components seem to be, we’re hopeful that Hubble will be giving us a very good scientific return for throughout this decade and maybe beyond.

And this is really good news because Hubble is terrific on its own. But it’s also very powerful when used in complement with other observatories and probes, such as the James Webb Space Telescope, which is another space facility with different capabilities that we anticipate launching in 2021.

IRA FLATOW: Why do you think with all the wonderful telescopes around the world that Hubble is the one that people talk about?

JENNIFER WISEMAN: That’s a great question. So the Hubble Space Telescope has really become a household a friend for people around the world. And I think there are several reasons for that. One is its dramatic beginning back in the early 1990s. Its launch from the Space Shuttle was momentous.

And then it was quickly realized that at first, Hubble’s images were disappointing. There was a realization that the magnificent 2.4-meter mirror inside Hubble was slightly misshapen. It was beautifully ground but slightly misshapen in its formula. And so this was kind of embarrassing for NASA. It was a disappointment to astronomers. And this was a bad way to get your name known around the world.

But because of that, its dramatic repair mission in 1993 was watched by people around the world. And when the results of that mission were so successful, people were cheering around the world. So that, again, reinforced the name of Hubble around the world.

And then the early images after that first repair mission were surprising and dramatic. One of them was when Comet Shoemaker-Levy 9 collided with Jupiter. It fell apart into this series of fragments that impacted Jupiter one by one. And the Hubble Telescope caught this dramatic impact. And how memorable is that? That’s something that really only Hubble could capture in that kind of detail. So that reinforced the name of Hubble.

And then the most dramatic images that are of most interest to the public are easily accessible also in the galleries on our websites. And I think that people appreciate that. They’re able to share in the awe and wonder of looking at these images of galaxies, of stars, of these beautiful, colorful nebulae where stars are still forming. And I’m pleased that the mission has set a standard for making these observations and data easily available and enjoyable worldwide.

IRA FLATOW: Wow. We have run out of time. There’s so much stuff to talk about with the Hubble. I want to wish you and congratulate you and wish everybody a happy 30th anniversary for the Hubble.

JENNIFER WISEMAN: Thank you. Check us out on social media, @NASAHubble. A lot going on there.

IRA FLATOW: Dr. Jennifer Wiseman is the senior project scientist for the Hubble Space Telescope in Greenbelt, Maryland. Thank you for taking time to be with us today.

JENNIFER WISEMAN: My pleasure.

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