The Hubble Turns 20 The Hubble telescope has an impressive resume for a 20-year-old. It has helped scientists zero in on the age of the universe, and figure out that the universe is expanding. Ira Flatow and guests look back at the telescope's contributions to science and pop culture.
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The Hubble Turns 20

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The Hubble Turns 20

The Hubble Turns 20

The Hubble Turns 20

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The Hubble telescope has an impressive resume for a 20-year-old. It has helped scientists zero in on the age of the universe, and figure out that the universe is expanding. Ira Flatow and guests look back at the telescope's contributions to science and pop culture.


Up next, it's a birthday celebration. Twenty years ago tomorrow - can you believe this? It's just 20 years ago that the Hubble Space Telescope it seems like yesterday was launched into space, and you remember what happened? Right after it was launched, people said uh oh, it's sort of blind. It's a failure. Something is wrong with the telescope. There's a flaw.

There sure is. There was a flaw in one of its mirrors that left the Hubble in need of sort of a pair of glasses, and well, things changed in 1993. NASA sent up a repair team, a mission to fix the Hubble, and after that, everything, everything turned around.

And those gorgeous pictures started pouring in, and since then the Hubble has become the crown jewel of NASA, helping scientists not only look at those nice pictures but to zero in on the age of the universe, confirm the existence of dark energy, peer back into time further than any telescope had, and showing us what the universe looking like about a billion years ago or billions of years ago, and not to mention, as I say, those jaw-dropping Hubble images that even adorn everything.

You can buy them in bookstores, album covers, all kinds of places. Who would have thought images of the galaxies would have been so popular.

But it's not finished yet. In fact, there's a new image on our Web site commemorating the 20th anniversary. It was just released. It shows a part of a nebula that they have enhanced, the very famous one you might have seen years ago, and you can see it at our Web site on Surf over to our site at, where it is, or also you can send us a tweet, if you'd like to join, @scifri, @-S-C-I-F-R-I, as we talk to my next guest.

Mario Livio is the he's an astrophysicist at the Space Telescope Science Institute. His latest book is called "Is God a Mathematician?" It's just out in paperback. He joins us from Baltimore. Welcome back to SCIENCE FRIDAY, Dr. Livio.

Dr. MARIO LIVIO (Space Telescope Science Institute): My pleasure.

FLATOW: You're welcome. Ron Cowen is astronomy and space science reporter for Science News. You can see his article on Web site. He joins us from our NPR studios in Washington. Welcome back.

Mr. RON COWEN (Astronomy and Space Science Reporter, Science News): Thanks, Ira.

FLATOW: You devoted a whole issue, almost, to the triumph of the Hubble.

Mr. COWEN: Yes, that's right. We just thought it was that important, and I mean, in so many different ways the fact that this telescope has almost had a it has had a roller-coaster, soap-opera-like existence, going from failure to triumph to then, after the terrible Columbia shuttle disaster, the administrator then saying, well, there's not going to be any more servicing missions, and then the cameras dying, and then that mission was revived. So there's that.

There's all the discoveries, all the beautiful images, the fact that the public has embraced this telescope like no other and has learned so much about astronomy from it, yeah.

FLATOW: It's true. Mario, tell us about this special image that was released this week on the 20th anniversary. How was it different from all the other images?

Dr. LIVIO: So well, of course it's also an image of something that's right up there in the heaven. This particular image is part of the Carina Nebula, which is a famous region where new stars are being born.

We chose an image that shows one pillar of gas and dust, inside which new stars are born. The two stars in the image you can see are having very powerful jets that come to both sides, and the whole structure there, if you like, is sculpted by radiation from very luminous stars that are not in the image.

The radiation basically erodes away all the less-dense material, all the less-dense gas and dust, leaving behind only the densest columns, and this is why the whole thing appears as a column or a pillar that points towards those very luminous stars.

FLATOW: This is a re-imaging of one of the most popular of the Hubble images, is it not, that was taken back...

Mr. COWEN: No, you probably think of the Eagle Nebula, which is one of the iconic images of Hubble. This is that's another nebula. This one is so spectacular that we refer to it as Eagle Nebula on steroids.

(Soundbite of laughter)

FLATOW: I guess that's why I got it confused because you called it the Eagle Nebula on steroids.

Dr. LIVIO: Yeah, right, but it's not the same region. It's a different region. It does have this landscape feel to it, very fantastic landscape.

FLATOW: All right, we're going to have to take a break, and if in the meantime you would like to see the image of this new Hubble image, you can go to our Web site at, where it is up there, and also we can send you to the other images of the Hubble on this -tomorrow the 20th anniversary of the Hubble Telescope.

We're going to talk a lot more with Mario Livio and Ron Cowen. Our number, 1-800-989-8255, 1-800-989-8255. Tell us what you like most about the Hubble. Tell us what you didn't like. Tell us what you would like to see that you haven't seen already. Where should we point the Hubble at? 1-800-989-8255, tweet us @scifri, @-S-C-I-F-R-I. We'll be right back after this break.

(Soundbite of music)

FLATOW: You're listening to SCIENCE FRIDAY from NPR News. I'm Ira Flatow. We're talking about the 20th anniversary of the Hubble Space Telescope with my guests, Mario Livio he's an astrophysicist at the Space Telescope Science Institute in Baltimore; also Ron Cowen is astronomy and space science reporter for Science News. You can check out his articles in Web site.

Our number, 1-800-989-8255. Let's go right to the phones, because you would guess it, people have great questions about the Hubble. Hi, Holly, Holly in (unintelligible), California. Welcome to SCIENCE FRIDAY.

HOLLY (Caller): Thank you. I'm calling because I was so pleased to see all of the pictures. There's a Web site that publishes pictures on a daily basis, and it has a little educational piece about them. But I had heard from a friend that those pictures are color enhanced. Is that true?

FLATOW: Good question. What about this latest photo? Is it real color, Mario or Ron?

Mr. COWEN: Well oh, go ahead, Mario. Do you want to talk first?

Dr. LIVIO: Yeah, so the way it works is the image is taken in several filters. The filters sometimes happen to be red, blue and green filters, in which case we can actually reconstruct the real colors of the image, if you like. Sometimes we take an image in wavelengths that humans cannot see, like ultraviolet light or infrared light, like heat radiation. In those cases, we need to represent the light that we cannot see with our eyes with something like red or blue or green. In that case, we call it false colors.

This particular image actually was taken with a channel that looks at visible lights and with the right filters, so this is probably as close as you can get to something that you might call real colors.

FLATOW: Ron, your article in addresses this whole image question.

Mr. COWEN: Yes, it does, and we actually start with the raw black and white images - I mean, taken at specific wavelengths and how it was assembled.

I would just say for this image, the Carina Nebula, in fact two of the wavelengths of the three that were taken in visible light they're both really reddish wavelengths, and the redder of the two was assigned red, and then the slightly bluer of the red wavelengths, if you will, was assigned green, and then there was a third filter, which is blue.

And so there is some subjectivity about how you put this together. I think that you can see that, but even an astronomer, actually, really needs to see how - the contrast and some of the enhancement to bring out astronomical features.

But it is not exactly what the eye would see, but as Mario said, I mean, some of it's invisible, and some of it, we our eye, even if we had Hubble's acuity, just couldn't pick out the - some of the features that you really want to focus on, like these, the pillars where the of gas and dust where stars are being born and these images wouldn't come out as clearly if it was just our human eye without some shadowing.

So there is some enhancement done, but it's done in an astronomically accurate way, I would say.

FLATOW: Holly, does it matter to you if it's...

HOLLY: Well, I guess from a non-scientific standpoint, my main concern is when I am out in the heavens, as would be my religious belief of really where life began and where I'm going afterward, will it look that way to me when I'm there?

FLATOW: Well, not quite if this is a false-color image, but who's to say? Who's to say what you can see when you're out there in heaven?

HOLLY: I'll tweet you back.

(Soundbite of laughter)

FLATOW: Thanks for calling, Holly. Have a good weekend.

HOLLY: Thank you.

FLATOW: 1-800-989-8255 is our number. Let's talk about some of the triumphs that Hubble had. Let's talk about, Mario, first about dark energy. Did the Hubble discover dark energy?

Dr. LIVIO: So you know, most of the Hubble discoveries are such that they were not exclusive discoveries to Hubble. Discoveries in astronomy are often done by several telescopes working together. So in that particular case, again, these were many telescopes from the ground and the addition of Hubble, and then other space telescopes also were added to this and, of course, WMAP, which is another satellite also added to this.

But Hubble's role in dark energy was absolutely crucial. So dark energy is that stuff that pulls, pushes our universe to accelerate. We knew that our universe is expanding, but we thought it should be slowing down because of gravity. Instead, it is really speeding up.

And Hubble was really crucial in discovering that and determining the properties of this dark energy.

FLATOW: Ron, anything to add?

Mr. COWEN: No, I will totally agree with that, but I will say also determining the age of the universe to better than 10 percent, and the universe is about 13.7 billion years old looking back in time to galaxies that they're only roughly 480 million years after the Big Bang.

I should say more accurately these are candidates for being that old because it's at the very limits of what the new, of what the refurbished Hubble Telescope can do, looking at the atmospheres of extra-solar planets, planets beyond the solar system, actually being able to identify what's in those atmospheres.

And so there's - verifying some of the first really great evidence for super-massive black holes being at the centers of galaxies came from Hubble Space Telescope images and spectra.

FLATOW: What is there left that where do we point it, and how much let me go back one step, and with the repair missions that were just completed - how much life can we expect then the Hubble to...

Mr. COWEN: How much life?

FLATOW: Yeah, how many years left does the Hubble have?

Dr. LIVIO: So Hubble will operate for at least five more years, but we hope, and, you know, every indication is, that if all goes well it could definitely operate for more than that, for maybe seven, eight years, possibly even 10.

FLATOW: You should have the luck of the Mars Rovers with you on the Hubble.

(Soundbite of laughter)

Dr. LIVIO: Yes. Well, you know, we already had the luck that it worked for as long as it has worked. You know, it was not meant to work for 20 years originally.

Mr. COWEN: It was, I think, 15 years originally, Mario, is that right?

Dr. LIVIO: Right, right, it started with 10, 15, and you know, and now 20, and we'll have at least another five. So there is a lot left, to be honest.

I mean, you know, even in some of the topics that Ron mentioned, you know, topics like the atmospheres of planets around other stars, there is a lot of work to still be done.

One topic that Ron did not mention is the mapping of dark matter -that's matter that we cannot see because it does not emit any light, but it really holds galaxies and clusters of galaxies together - so to map that on a very large school.

And in almost even in the topics in which discoveries have already been made, there is just so much more to learn. You know, how do stars how are they born? How are they how do they die? The evolution of galaxies from the beginning of time to today. All of this is still left to be explored.

FLATOW: Let's go to let's get a question in from Second Life. Archivist Luellen(ph) asks this is a good question what is the difference between Hubble and the upcoming Webb Space Telescope? Would it be right to call it a successor? It's really not a successor.

Mr. COWEN: In a way, it's a successor. I mean, James Webb Space Telescope is going to look in the infrared exclusively, and Hubble is looks in visible light. But James Webb, just generally speaking, it has a much it will have a much larger mirror, larger collecting area. So it's going to see deeper into the universe, and the infrared capability also means that it can see galaxies farther back in time.

I was going to say, too, that if Hubble does last five years or more, it will actually be up there, we hope, at the same time as James Webb Space Telescope, and the two can look together, Hubble in visible light and the near-infrared and James Webb at longer infrared wavelengths.

FLATOW: Is that because all the action, so to speak, is in infrared?

Mr. COWEN: That's right.

FLATOW: I mean, if you lose the Hubble, you lose the visible light, but I hear you saying - so what.

Mr. COWEN: Right...

Dr. LIVIO: Well, no, not so what. Not so what, but you see, if you want to look because the universe is expanding, all light from the very distant objects is shifted, actually, into the infrared. So if we want to see the very first galaxies in our universe, you have to look in the infrared, and that's what we hope the James Webb will be able to tell us. This is why it is an exclusively infrared observatory.

FLATOW: So if you lose the Hubble for the visible light, is there anything on Earth, ground-based, that could take anything close to the quality of those pictures?

Mr. COWEN: I think - there are the Keck telescope, and there's other large telescopes that have what's called adaptive optics, optics that, like, they have flexible mirrors that can compensate for the blurring due to Earth's atmosphere.

Obviously, Hubble has such clear vision because it's orbiting above all that. So I mean I'll let Mario answer too, but...

FLATOW: All right, let me go to a question, Mario.

Dr. LIVIO: Okay.

FLATOW: Rather than so many people want to ask questions. Let's go to Will in Orlando. Hi, Will.

WILL (Caller): Hi, how are you?

FLATOW: Hi, go ahead.

WILL: Yeah. I just - I read a great book called The Red Limit by Timothy Ferris, which had, you know, quite a bit of information about Hubbles discoveries. Its quite outdated now, but I just wondered if theres - if the telescope has been able to, you know, more appropriately identify the nature of quasars, which were at least at that time the most distant objects in space. And if - you know, I didnt know if theyve been able to identify individual stars or masses of gas and, you know, superheated energy. So I wondered what the Hubble telescope has done to enlighten us on that.


Dr. LIVIO: If I heard him correctly, he said quasars?


Dr. LIVIO: So quasars - yes, Hubble has done a lot with respect to quasars. So quasars are really super massive black holes at the centers of galaxies. And these super massive black holes, they collect matter from their surrounding. And as a result of these, they release vast amounts of energy. This is what gives them their power. So Hubble was able to actually image the host galaxies of such - some of these quasars, so we now know for sure that this is what they are. They are massive black holes at the centers of galaxies and they get their power from accreting or collecting mass from their surrounding.

FLATOW: Mm-hmm.

Mr. COWEN: I would just add that as it stands now, the most distant objects so far that we have recorded are - it kind of goes back and forth, but there are - galaxies are the most distant objects, as opposed to quasars.

FLATOW: Mm-hmm. Lets see if we can get some more interesting questions in. Lets go to Allen(ph) in Muskegon, Michigan, is it? Tell me.

ALLEN (Caller): Right.

(Soundbite of laughter)

FLATOW: Go ahead.

ALLEN: I was wondering if any of the Hubble long-distance viewing discovered anything or has to consider the curvature of space.

FLATOW: Can you see the curvature of space, youre asking, with the telescope?

Dr. LIVIO: Yes. So its really the best measurements of the curvature of space were done by the WMAP satellite. But Hubble, of course, you know, is involved in this - in the searches for dark energy and so on. But basically, WMAP has shown us that to a high degree of accuracy our universe is actually flat. So the curvature is zero essentially and it is flat like, you know, like your desktop.

FLATOW: Mm-hmm. Were talking about the Hubble Space Telescope this hour on SCIENCE FRIDAY from NPR. Im Ira Flatow, talking with Mario Livio and Ron Cowen.

Ron, we mentioned - you mentioned briefly, reiterating what I was saying a bit, that despite all these great technical achievements, theyre not scientific achievements, probably greater, having people looking at astronomy pictures and studying space.

Mr. COWEN: Mm-hmm. Yeah. I mean...

FLATOW: The interest is just amazing.

Mr. COWEN: Yeah. Millions of people go to the Hubble Web site. There are - these images are in art museums. Theyre - theyve been on the album covers of Pearl Jam and other covers. You know, President Obama, Im told, has one of the images now hanging on his wall. Yeah, its just -its something that just has gone beyond astronomy...


Mr. COWEN: a way that I think people really did never imagined that it would in the beginning, certainly.

FLATOW: Lets talk about, a bit, Mario, about exosolar planets. How many has Hubble discovered or is still looking?

Dr. LIVIO: So Hubble is not the best instrument to discover these things. Most of them were discovered from the ground. There are about 415 known now.

FLATOW: Mm-hmm.

Dr. LIVIO: But Hubble has contributed something very, very unique about these extrasolar planets. One of these things Ron mentioned before, namely - Hubble was able to tell us what elements are in the atmospheres of some of these planets. For example, in one case Hubble discovered water, methane, in the atmosphere of such a planet, or in other cases, sodium, hydrogen, oxygen and so on. So thats one thing that is very unique to Hubble. Another thing is that Hubble was able to actually image one such planet. Most of these planets are discovered not because we see them, but we see the tug, the gravitational tug that they exert on their parent star.

But in one case, Hubble was actually able to give us an image of this planet. And also, Hubble discovered some planets around the middle of our galaxy, halfway of a galaxy from us, halfway far, which is really unique to Hubble because most of the other planets that were discovered are really not very far from the sun.

FLATOW: Mm-hmm. 1-800-989-8255. Lets see if we can get a quick call before the break. Kevin in Hazel, Mass. Hi, Kevin.

KEVIN (Caller): Hi. My favorite picture from the Hubble was when they aimed it at an empty spot in the sky, and they left it on for several days and they looked at what, you know, what was there. There was thousands upon thousands upon you couldn't count them all, the galaxies.

FLATOW: Founded by accident, sort of...

KEVIN: Yes, sort of serendipity, more or less.

Dr. LIVIO: No. It was - they were not found by accident. Actually, that particular observation was very carefully planned. We specifically chose a point in the sky that appeared to be essentially empty because we wanted to see what is in the depths of space. And we were able to see that in an area of the sky, you know, like, if you would look through a drinking straw, in that area we could see thousands of galaxies. And they told us that in our observable universe there are about 200 billion galaxies like our own Milky Way.

FLATOW: Thanks, Kevin. Were there any accidental discoveries? You pointed and found something you werent looking for?

Dr. LIVIO: There are many things that we found that we weren't looking for - for example, dark energy. Even maybe the most important...

FLATOW: Mm-hmm.

Dr. LIVIO: ...discovery was - we were trying - we thought that the expansion of our universe should be slowing down, and two groups of astronomers were trying to determine the rate at which it was slowing down. And when they did that, they suddenly discovered, wait a minute, not only is it not slowing down, it's speeding up. And this is how dark energy was discovered.

FLATOW: Very interesting. 1-800-989-8255 is our number. You can also go to and see the latest image of the Hubble Space Telescope. And also send us a tweet at scifri, @S-C-I-F-R-I. We're going to take a break and come back and finish our conversation with Mario Livio and Ron Cowen. Stay with us. We'll be right back after this break.

(Soundbite of music)

FLATOW: You're listening to SCIENCE FRIDAY from NPR. I'm Ira Flatow. We're talking about the 20th anniversary of the Hubble Space Telescope with Mario Livio and Ron Cowen. He's astronomy and space science reporter for Science News. Our number: 1-800-989-8255. Mario, what - you touched on this briefly before. In a few minutes we have left, what's next immediately? Do you have a lineup of things to point the Hubble at?

Dr. LIVIO: Oh, absolutely. Every year we actually have a call for proposals and we receive more than a thousand proposals of things to observe. And then we have a very careful and elaborate process by which groups of specialists are determining what Hubble will actually look at. And we are now in this process, so we will know what Hubble will be looking at in the following year. And like I said, this process repeats itself once a year.

FLATOW: So you haven't got anything specific you can talk about yet, 'cause you're still reviewing the process?

Dr. LIVIO: Yes. We are currently in the review process. But you know, I can tell you already that we will be certainly looking at more things that have to do with galaxy formation, evolution...

FLATOW: Right.

Dr. LIVIO: ...more things that have to do with planets, more things that have to do with dark energy and so on.

FLATOW: Hey, can you take any, you know - you know what's hot now that you couldn't do, or maybe you can still do it with Hubble 3-D pictures? Can you give us any 3D images? Everybody wants 3-D now.

(Soundbite of laughter)

Dr. LIVIO: Actually, we are. Even this image that we released today, we actually released a 3-D version of it as well. So we will actually now quite routinely create 3-D images from - for our releases. And also, as you may know, there is a Hubble 3-D IMAX movie that is running now...

FLATOW: Right, right.

Dr. LIVIO: many theaters, which has a part of it where actually you can fly through some of the Hubble observations.

FLATOW: Yeah, we talked about that with the IMAX folks before. Ron, what do you see the future? What do you see in the future?

Mr. COWEN: Well, I think definitely looking for more distant galaxies seen - although James Webb Space Telescope will do more of this, but seeing, I mean, how many galaxies are there at - when you're at just 480 million years after the Big Bang? I mean, are you starting to come finally to the very beginning of galaxy formation, or does galaxy formation continue even earlier than that? And then there's - it's a very important question philosophically, but also, I mean, you start to get the issue, well, how many, you know, don't you need a certain number of millions of years to get a galaxy together, or can it form that quickly and be that big that much - so early in time? I think that's going to be a key thing and more observations related to dark energy.

FLATOW: And the further away we see, the further back in time.

Mr. COWEN: That's right, that's right.

FLATOW: And how far can - back in time can the Hubble see?

Mr. COWEN: Well, I mean, Hubble has now seen galaxies that they believe, they are 13.2 billion light years from Earth and that corresponds in time to about 480 million years after the Big Bang.

FLATOW: Mm-hmm. I was, you know, people I ask, you know, they want to buy a telescope for their own backyard or a pair of nice binoculars, and they ask, what's the power, what's the, you know, what are the specs of my backyard binoculars? Can you give us a comparable figure so people can understand what the Hubble - the specs of the Hubble are? There's -how many power is it? Is light gathering? That sort of thing. Or that just a silly question?

Dr. LIVIO: They don't compare that easily, I mean, because it's, when you buy it for your backyard, it's usually a magnification power thing and so on. And with the Hubble we don't measure things in this way. But what people often tell me, well, I cannot see with my binoculars what you can see with the Hubble Space Telescope. And I say, well, yeah, this is why, you know, it costs a few billion dollars to build.

Mr. COWEN: But isn't this something about with resolution, Mario, that it's sort of like if you're in New York, you can distinguish two pennies close together that were in California. Is that - there is some analogy...

Dr. LIVIO: That's about it, or you can distinguish the headlights of a car in Tokyo, if you could see that, and you could tell that there are two.

Mr. COWEN: From looking from New York?

Dr. LIVIO: From New York.

Mr. COWEN: Okay.

FLATOW: Wow. But you never ever point it at the Earth, do you.

Dr. LIVIO: No.


Dr. LIVIO: No.

FLATOW: All right, we want to thank you very much for taking time to be with us, and wish you a happy anniversary...

Dr. LIVIO: Thank you very much.

FLATOW: ...and we wish many more years of Hubble photos and data coming back so we can talk about them.

Mr. COWEN: Right. So do I. Thank you.

(Soundbite of laughter)

FLATOW: Mario Livio is an astrophysicist at the Space Telescope Science Institute. That's in Baltimore. His latest book is titled "Is God a Mathematician?" Also joining us is Ron Cowen. He is the astronomy and space science reporter from Science News. And you can read his story and his stuff on the Web site Thank you both for taking time to be with us today.

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