Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS
Transcripts

NOVA scienceNOW: July 28, 2009

PBS Airdate: July 28, 2009
Go to the companion Web site

NEIL DeGRASSE TYSON (Astrophysicist/American Museum of Natural History): On this episode of NOVA scienceNOW: we humans have always been obsessed with the moon.

NEIL ARMSTRONG (Archival Footage): That's one small step for a man, one giant leap for mankind.

NEIL DeGRASSE TYSON: And ever since we took that first step onto its surface, we've wondered if it could one day be our home away from home.

DANIEL ANDREWS (NASA Ames Research Center): We want to move to longer stays, to habitation.

NEIL DeGRASSE TYSON: But to live on the moon, we need to find water there. And a new NASA mission is on the hunt.

So this is LCROSS?

They're going to smash an empty rocket into a lunar crater at 5,600 miles per hour. If the explosion reveals enough hidden water, it could make motels on the moon a lot more likely.

ANTHONY COLAPRETE (NASA Ames Research Center): ...water, that's why we're going.

NEIL DeGRASSE TYSON: And what if somebody called you a birdbrain? Wouldn't you be insulted?

OFER TCHERNICHOVSKI (The City College of New York): Oh, a great compliment!

EINSTEIN (A Parrot): Hello!

OFER TCHERNICHOVSKI: The bird brain is a very good brain.

NEIL DeGRASSE TYSON: So good, a bird brain came up with this.

CHAD COHEN (Correspondent): So that's Beethoven's Fifth, out of the mouth of a wood wren.

NEIL DeGRASSE TYSON: Now these clever creatures are helping us solve the mystery of how humans learn to talk.

JUAN URIAGEREKA (University of Maryland): For an organism that is so distant from us, that's quite remarkable. Nature is playing a very slick trick, right there.

NEIL DeGRASSE TYSON: Also, we'll take you 2,000 feet below the surface of the earth on an underground hunt in search of ancient life.

ZIYA TONG (Correspondent): So these walls are just pure salt?

JACK GRIFFITH (University of North Carolina): Pure salt.

NEIL DeGRASSE TYSON: Hidden within these walls are salt crystals that could hold the remains of microbes older than any organic matter ever found on Earth.

JACK GRIFFITH: That liquid was trapped a quarter of a billion years ago, so these are little microscopic time capsules.

NEIL DeGRASSE TYSON: All that and more on this episode of NOVA scienceNOW.

Funding for NOVA scienceNOW is provided by the National Science Foundation, where discoveries begin. And...

Discover new knowledge; biomedical research and science education; Howard Hughes Medical Institute: HHMI.

And the Alfred P. Sloan Foundation, to enhance public understanding of science and technology and to portray the lives of men and women engaged in scientific and technological pursuit.

And the George D. Smith Fund.

And by PBS viewers like you. Thank you.

MOON SMASHER

NEIL DeGRASSE TYSON: Hi, I'm Neil deGrasse Tyson, your host for NOVA scienceNOW.

Forty years ago, humans landed on the moon. We went back five more times, but stayed only a few days each trip. Many of us hope that someday we can stay longer, establish a permanent base here, maybe even use it as a rest stop for interplanetary travel. But if that's going to fly, the moon's got to give us a little more help by providing some basic resources. One major resource NASA hopes to find, any day now, is water.

Who can deny it? We all have a certain fascination with destruction. Explosions, collisions, they're an undeniable guilty pleasure. And for a lucky few at NASA, destruction is actually part of their job description.

PETER SCHULTZ (Brown University): I blast things. I've done this since I've been a kid. That's exactly what I'm doing now. I'm a grownup, and I still play in the sandbox. I get to throw things at very high velocity.

NEIL DeGRASSE TYSON: This is Peter Schultz's playground: the vertical gun range at NASA's Ames Research Center, in Northern California. For more than 30 years, Schultz and his team have been loading projectiles into this 30-foot steel barrel, mounted on a lifting arm. They then fire them into small models of planetary surfaces.

So this is the gun, huh?

PETE SCHULTZ: Yeah, yeah, this is the big gun.

NEIL DeGRASSE TYSON: But it looks like a contraption, like something out of Jules Verne.

PETE SCHULTZ: It was made in the '60s, so this is at the birth of Apollo. This is when...this is the type of gun that they made to try and understand the moon.

NEIL DeGRASSE TYSON: The surface of the moon?

PETE SCHULTZ: The surface of the moon.

NEIL DeGRASSE TYSON: Getting to the moon and colonizing it have always been the target of human obsession. But it was 1969, before we really started to understand the moon firsthand.

NEIL ARMSTRONG (Archival Footage): I'm going to step off the LEM, now. That's one small step for a man, one giant leap for mankind.

NEIL DeGRASSE TYSON: Exciting as that first step was, the moon looked pretty bleak. In the nearly 50 pounds of moon rocks brought back by Armstrong, Aldrin and Collins, scientists found hardly any ingredients—like nitrogen, hydrogen and carbon dioxide—that are essential to support human life. And without the most important of them, water, the moon would forever remain hostile to human colonization.

Lunar scientists had long theorized that large stores of water might have accumulated on the moon, just as they did on Earth, deposited by the impacts of comets. But they believed any water near the surface, exposed to the sun, would have long since evaporated. In 1998, NASA launched Lunar Prospector, a small spacecraft designed to orbit the moon pole-to-pole. It carried a highly sensitive spectrometer, a device tuned to detect hydrogen, a possible sign of water, to a depth of three feet, even in areas of permanent darkness.

And in the darkest craters, near the moon's poles, Prospector struck the mother lode: signs of water, up to six billion tons of the stuff. This hint of water changed the game in an instant.

DANIEL ANDREWS: Water makes up, sort of, the foundational building blocks for living on the land on the moon. A half-liter bottle of water, on average, might cost $15,000 to bring it to the moon. That's crazy. What if the water was there? You could be using it to create fuel and use the moon as a launching point to go to other places.

NEIL DeGRASSE TYSON: So, for NASA, finding water on the moon may in fact be the next big step toward space colonization. But before we can think about living up there, we have to make sure we know where the water is. And NASA has a new mission aimed at doing just that.

So this is LCROSS?

STEPHEN HIXSON (Northrop Grumman Corporation): This is LCROSS.

NEIL DeGRASSE TYSON: Meet LCROSS, NASA's next big step in the hunt for lunar water.

It looks like this ring, right, with just these things stuck on it.

STEPHEN HIXSON: It actually looks like a sewer pipe.

NEIL DeGRASSE TYSON: Short for Lunar Crater Observation and Sensing Satellite, LCROSS is a small and simple spacecraft, designed to sit on top of the upper stage of its launch rocket and take control of the rocket when it's empty.

LCROSS's purpose is to smash that school-bus-sized empty rocket stage into a dark lunar crater at 5,600 miles an hour. The impact will toss the crater's contents high up into the sunlight, where LCROSS can analyze them in great detail, and perhaps find new proof of lunar water.

Remember Pete Schultz's vertical gun? Well, its purpose is to prepare NASA to experience on Earth what LCROSS will encounter on its Moon mission.

To do that, Schultz's team loads a projectile that will act as a stand-in for the empty rocket stage that LCROSS will throw at the moon. Then they stand back and watch what happens inside the chamber.

So we're about to go in here, but tell me, first, the gun's not loaded.

PETE SCHULTZ: Let me check.

NEIL DeGRASSE TYSON: Inside the chamber, which will later be drained of air to mimic the moon's lack of atmosphere, Schultz prepares his own little mini-diorama of the lunar surface, using an array of highly specialized gear.

This is not the surface of the moon, because it's smooth.

PETE SCHULTZ: That's right, so now we have to make some craters, so...

NEIL DeGRASSE TYSON: That's the fun part.

PETE SCHULTZ: Yep, that's right.

NEIL DeGRASSE TYSON: The whole idea here is to recreate the situation that LCROSS will observe when it flies through the dust plume created by the impact of its empty rocket stage.

It takes about 20 minutes to suck the air out of the chamber. The tension builds, then comes the moment of, well, silence. Hey, there's no sound in a vacuum, all right? But the results are still impressive.

PETE SCHULTZ: Look at this! See this? That's the red stuff, and now that's coming into light.

NEIL DeGRASSE TYSON: Into sunlight?

PETE SCHULTZ: Into sunlight, and you're seeing the ejecta.

NEIL DeGRASSE TYSON: And the red stuff is glowing red-hot.

When the simulation is slowed down, the beauty and complexity of the plume become apparent. It won't just be a big pile of moon dirt. It'll be a delicate trumpet-shaped curtain of lunar dust, spreading out from the center of the impact site.

It is beautiful, but how will NASA be able to tell what it's made of and if there is water to be found? In this makeshift lab, team members are using some inexpensive drugstore supplies to test what LCROSS will see when it analyzes the impact's dust curtain.

ANTHONY COLAPRETE: However, the lunar dust is quite fine, like baby powder, so it's not too far an analog-...

NEIL DeGRASSE TYSON: Wait, wait, wait. What's this thing?

ANTHONY COLAPRETE: That's a vibrator.

NEIL DeGRASSE TYSON: I've seen these. This feels good.

ANTHONY COLAPRETE: It does feel good.

NEIL DeGRASSE TYSON: As the baby powder is shaken through the sieve, the team tests how the sun's light will be reflected and scattered when it passes through the dust to LCROSS's optical spectrometers.

So what you're really doing is exploiting the fact that the sunlight is coming through the dust, in order to analyze the dust itself?

ANTHONY COLAPRETE: That's right.

NEIL DeGRASSE TYSON: As sunlight passes through the dust curtain, the compounds in the dust absorb specific frequencies of light. LCROSS's optical spectrometers measure which frequencies are absorbed, and from those measurements, scientists can tell exactly what the dust is made of. If LCROSS is lucky, it will see a telltale signature like this, indicating...

ANTHONY COLAPRETE: ...water. That's why we're going.

DANIEL ANDREWS: We want to move from just sorties to longer stays, to habitation.

NEIL DeGRASSE TYSON: Launched just last month, LCROSS sat on top of a two-stage rocket. About two hours after liftoff, the primary payload was sent on its way. Next, instead of throwing away the empty second stage, tiny LCROSS held onto it. This will be its projectile. Then, LCROSS began shepherding this empty space junk in two huge orbits, out past the moon

and all the way back around the earth. This slingshot trajectory is required to get LCROSS and its projectile up to speed and lined up perfectly with the target crater near the moon's north pole. Then comes the final delicate dance.

ANTHONY COLAPRETE: Eight hours prior to impact, we let go of that upper stage of the rocket, the Centaur, and we watch it as it goes in and impacts. When it impacts, it makes an explosion. Our little shepherding spacecraft now becomes an observing spacecraft. Eventually, we actually fly through the plume itself, making measurements the whole time, and impact ourselves.

NEIL DeGRASSE TYSON: About two and a half months after launch, LCROSS will meet its demise. And if it does hit its mark, the resulting 40-mile-high debris plume should be visible from Earth through an amateur telescope. And in one fleeting instant, the LCROSS team will know success or failure.

But on a grander scale, much more is at stake. If LCROSS does find water, we may just be looking at the first rest-stop on our way to the stars.

On Screen Text: The first spacecraft to crash into the moon was the Soviet Luna 2 probe in 1959. In 1965, Americans had a live camera on Ranger 9 as it collided. The Apollo program smashed 5 spent rocket stages and 4 lunar module ascent craft. Japan, India, China and the European Space Agency did too, for a grand total of 39 impacts.

SECRETS IN THE SALT

NEIL DeGRASSE TYSON: In ancient Egypt, they used salt to preserve their dead. It worked so well, bodies thousands of years old are still around today, looking pretty good, too. Well, now researchers are uncovering evidence that salt has preserved life forms much older than any pharaoh. Correspondent Ziya Tong explores a place where the ultimate natural preservative may enshroud remnants of life a quarter-billion years old.

ZIYA TONG: At a high-security government facility, in the middle of the New Mexico desert, a team of experts are getting ready for an expedition. Microbiologist Jack Griffith, biologist Bonnie Baxter and research analyst Smaranda Wilcox have agreed to take me with them to a place few people ever get a chance to see.

After gearing up, we're escorted to an old industrial elevator which will take us 2,000 feet below the surface of the earth.

There's no H for "Hell" button.

We're going on an underground hunt, in search of ancient life.

So how far deep do you think we are, in terms of time, as we're going down?

JACK GRIFFITH: It's about two million years per second.

ZIYA TONG: Two million years a second that we're heading down?

JACK GRIFFITH: Past the dinosaurs.

BONNIE K. BAXTER (Westminster College): There's a dinosaur.

JACK GRIFFITH: So in a way, this is a time machine, a very fast time machine.

ZIYA TONG: A time machine that descends through layer after layer of ancient rock.

Finally we stop, get out and find ourselves smack in the middle of a salt formation over a quarter of a billion years old.

Imagine Planet Earth, 253 million years B.C.: a world before the age of dinosaurs, even before flowering plants. True mammals hadn't evolved yet, but the insect population is thriving.

It was during this time period, known as the Permian, that the salt deposit was formed. It started out as an enormous salt lake in the middle of an intensely hot desert.

DENNIS POWERS (University of Mississippi): Two-hundred-fifty-million years ago, it would have been just absolutely miserable. The temperature might have been 140 degrees.

ZIYA TONG: All that heat caused the lake to dry up, leaving behind an enormous pile of salt, hundreds of miles wide. Over time, the salt got buried under a 1,500 foot layer of rock, where it remained isolated and protected from the catastrophic events that were about to change the face of Planet Earth forever.

The Permian world ended with the most devastating extinction event of all time. Most forms of life died off, and scientists still aren't sure why. But, down here, the team believes, remnants of this mysterious time period had a chance to survive, buried in crystals of salt, an idea originally inspired by Bonnie's work. For over a decade she's studied how salt crystals form in salt lakes.

BONNIE BAXTER: In modern salt that we collect from the shores of Great Salt Lake, we find lots of microbes, bacteria and things like that, that live inside the salt crystals.

ZIYA TONG: That's because, as salt crystals form, microscopic pockets of water often get trapped inside, and with it, salt-loving microbes. That got Bonnie thinking, "Could ancient microbes from the Permian have survived the same way?"

JACK GRIFFITH: It opens up a door to this world that existed a quarter of a billion years ago.

ZIYA TONG: A door that could fill in missing pieces of the evolution of life on the planet. But to do that, the team needed access to ancient salt.

It turns out, the U.S. government has plenty of it. Back in the 1990s the Department of Energy hollowed out miles and miles of tunnels right through this Permian salt formation.

What is the D.O.E. doing with miles of underground tunnels? They use it to store radioactive waste.

So this is, like, nuclear waste?

ROGER NELSON (United States Department of Energy): This is radioactive waste resulting from the production of atomic bombs. You're looking at the legacy of the Cold War between the U.S. and the Soviet Union.

ZIYA TONG: A legacy the D.O.E. believes is best kept deep below the surface of the earth.

But, for scientists, these underground tunnels serve a very different purpose, providing rare access to salt that's been buried under a protective layer of rock for hundreds of million of years.

So these walls are just pure salt?

JACK GRIFFITH: Pure salt. The reddish is some sulfur deposits, then the browner areas contain clays. So, what we're looking for are some of these little areas that are clear, because the clear area very likely contains possibly D.N.A., bacteria, we don't know.

ZIYA TONG: Right.

JACK GRIFFITH: Yeah. So, there's a piece.

ZIYA TONG: Wow.

JACK GRIFFITH: I'll have a piece too.

ZIYA TONG: It tastes...

JACK GRIFFITH: ...just like salt.

ZIYA TONG: Pretty much just like the modern stuff, huh?

JACK GRIFFITH: It does. It does. Probably in a French restaurant it would be very pricey.

ZIYA TONG: Yeah, I imagine so.

JACK GRIFFITH: Of course we don't know what's in it.

ZIYA TONG: I wonder what you could get for this on eBay.

Soon we were joined by geologist Dennis Powers. He's spent years studying this formation.

JACK GRIFFITH: What do you think, Dennis? Are we in a good area here?

DENNIS POWERS: Yeah, we'll just follow this line along here. You see the light shining into the crystals, and it starts to disperse out, and the whole wall lights up here, just like that. That would be the kind of place we want to sample, Jack.

ZIYA TONG: They mark a spot where the salt crystals are clear and drill several inches into the wall to remove them. What we were about to unearth literally hadn't seen the light of day for over a quarter of a billion years.

It looks like those rock sugar candies that I used to eat.

BONNIE BAXTER: It's so clear, look at that. You can see right through it.

ZIYA TONG: There's little bubbles in there, huh?

JACK GRIFFITH: Little bubbles, we'll have to see what they are.

ZIYA TONG: It takes a few minutes for us to get back to the surface, where I can finally get a better look at the mysterious tiny bubbles the team came here to find.

JACK GRIFFITH: Can you see the little bubble as we rotate the crystal?

ZIYA TONG: Yeah.

JACK GRIFFITH: That cavity and the others are full of liquid, and that liquid was trapped a quarter of a billion years ago, when the salt deposit was formed. So these are little microscopic time capsules.

And the hope was that, perhaps, these tiny liquid time capsules might contain biological molecules that were synthesized before the great Permian extinction, 250 million years ago.

ZIYA TONG: Ancient liquid, older than the dinosaurs, even older than flowering plants. But does it really contain remnants of ancient life inside? Back home in North Carolina, Jack is determined to find out. At the Griffith lab, that means devising a way to photograph what's inside these tiny time capsules with an electron microscope, a difficult and delicate process.

Jack is renowned for his extraordinary images of the smallest of things, like D.N.A. and protein.

BONNIE BAXTER: He is simply the best person in the world to photograph tiny molecules of life.

ZIYA TONG: Smaranda starts by sterilizing the salt crystals.

SMARANDA WILLCOX (University of North Carolina): We put the salt crystals in this very potent acid mix. The acid will eat away anything that's on the surface, and then I look at the crystal.

ZIYA TONG: Cracks mean modern contaminants have a chance of getting inside, so those crystals are discarded. Then they drill a tiny hole, the size of a cat's whisker, right into the tiny time capsule. Now it's time to remove the ancient liquid and discover whether any remnants of life have actually survived a quarter of a billion years.

JACK GRIFFITH: The sample was covered with these fibrous materials that you see here. A lot of it looks like some pasta...

ZIYA TONG: Right.

JACK GRIFFITH: ...that had been laid down in flat sheets. And we've never seen this before.

ZIYA TONG: Well, what are we looking at here?

JACK GRIFFITH: Well, we didn't know because we've been doing this for 30 years, this was new. So the question is what was it?

BONNIE BAXTER: We were absolutely flabbergasted.

SMARANDA WILLCOX: It was a stretch of imagination, really, to come up with what it could be.

ZIYA TONG: No one ever suspected that these pasta-like noodles were, in fact, ancient cellulose.

JACK GRIFFITH: We think D.N.A., we think proteins, we think about R.N.A., but we had never really thought about cellulose, and so this was quite a surprise.

ZIYA TONG: But maybe it shouldn't have been, when you realize that every year the planet produces a hundred gigatons of the stuff.

Cellulose is a long chain of sugar molecules; it's produced by some forms of bacteria who live on it. But this tough little molecule is best know as the main component of the cell walls of all green plants, from algae, to leaves, to grass and trees.

Cellulose has the honor of being the most common organic compound on Earth. Two-hundred-fifty-million years ago, the landscape was positively overflowing with it.

What you've captured here is the actual...

JACK GRIFFITH: Is the real...

ZIYA TONG: ...organic material.

JACK GRIFFITH: This is the real, actual organic molecules that are a quarter of a billion years old, so these are clearly the oldest direct evidence of life on the planet. Fossils go back into the billions of years, but you're still looking at rock casts.

ZIYA TONG: Right.

JACK GRIFFITH: You can't do any biological tests on fossils. That's what's really most exciting about this material, that, not only can you see it, but you can actually do things with it in the test tube.

As new modern methods get better and better, there could be secrets that we could discover in the nature of cellulose that could tell us about many features of this ancient world.

On Screen Text: So what exactly is the radioactive waste they store down here?

We got to see inside the canisters with U.S. Department of Energy X-ray images, and it's mostly just contaminated tools and stuff, dating back as far as the Manhattan Project. Like these.

Can you find them in the X-rays?

BIRD BRAINS

NEIL DeGRASSE TYSON: You know, the ability to speak is one of those things that makes us humans think we're special.

EINSTEIN: Special.

NEIL DeGRASSE TYSON: But researchers have struggled to figure out exactly how we got this talent.

EINSTEIN: Talent.

NEIL DeGRASSE TYSON: Because learning to speak a language takes a lot more than just mindlessly parroting what someone else says.

EINSTEIN: Mindless.

NEIL DeGRASSE TYSON: Now, as correspondent Chad Cohen reports, we're finding new clues in the brains of some animals, who have the language ability to even rival our own.

EINSTEIN: Split infinitive!

CHAD COHEN: It's a skill that comes naturally to even the tiniest among us. We take in sounds, repeat them and learn to talk. We're so good at it, we can even do it in more than one language, like these little New Yorkers, who are learning French even before they've mastered English. And yet we still don't understand how.

It's a mystery scientists are starting to unravel by studying a brain about 1,000 times smaller than our own, a brain that's gotten a really bad rap.

If someone calls you a birdbrain how would you feel?

OFER TCHERNICHOVSKI: Oh, a great compliment! The bird brain is a very good brain.

CHAD COHEN: Ofer Tchernichovski, one of the world's leading experts in birdsong, thinks the term "birdbrain" is a real misnomer. In fact he believes the key to solving the mystery of speech lies in the notes of a bird's song.

OFER TCHERNICHOVSKI: By looking at the song and see how the song develop, you can understand, sometimes, very basic principles of how our brain works and how our mind works.

CHAD COHEN: In his lab, Ofer studies an Australian songbird called a zebra finch.

OFER TCHERNICHOVSKI: Now you can actually see them side by side.

CHAD COHEN: It turns out, this tiny bird learns to sing much like we learn to speak.

OFER TCHERNICHOVSKI: In the beginning, the bird will start singing a very faint, unstructured song, similar to babbling in human infants.

CHAD COHEN: It then starts to mimic the sounds it hears from the adults around it, a lot like we do.

MOM: Can you say ham? See the ham?

BABY: Ham.

OFER TCHERNICHOVSKI: So birds are vocal learners, and vocal learning is very rare in nature.

CHAD COHEN: While zebra finches learn only one song, other songbirds, like canaries, can learn new songs seasonally. Some hummingbirds learn songs more bug-like then bird-like. And parrots, like this one named Einstein...

EINSTEIN: Hello.

CHAD COHEN: ...can even mimic other species...

TRAINER: Can you do a pig?

EINSTEIN: Oink, oink, oink, oink.

CHAD COHEN: ...adding new words to their repertoire all the time.

TRAINER: What does everyone say in Tennessee?

EINSTEIN: Yahoo!

CHAD COHEN: Einstein seems content to receive a treat for displaying his vocal talents. In the wild though, male songbirds use their song to defend territory or to woo a mate. The guy with the best song gets the girl, but to get her, he's got to be creative...

OFER TCHERNICHOVSKI: Every individual bird has his own song, has his own performance, so they imitate, but they also diverge and vary.

CHAD COHEN: ...and in the process, create rather sophisticated melodies.

OFER TCHERNICHOVSKI: So here is a song of a veery. Let's listen to it a little. Does it sound musical to you?

CHAD COHEN: It sounds like a bird.

OFER TCHERNICHOVSKI: Okay, I'll slow it down for you.

CHAD COHEN: That's incredible. That's incredible. That's the same bird?

Birdsong is so elegant it's inspired the great masters. Mozart borrowed these notes from his beloved starling. When his muse died, the distraught maestro even gave it a formal funeral and wrote a poem in its honor.

OFER TCHERNICHOVSKI: Let me play you something and see if it reminds you of a piece of music, okay?

CHAD COHEN:Okay.

OFER TCHERNICHOVSKI: So here is a wood wren song.

CHAD COHEN: Da da da da. So, that's Beethoven's Fifth out of the mouth of a wood wren. That's just crazy. That's just crazy.

OFER TCHERNICHOVSKI: Beethoven was really a fraud, huh?

CHAD COHEN: Yeah. So which came first, though?

OFER TCHERNICHOVSKI: He came first, I can tell you that, at least a few thousand years earlier.

CHAD COHEN: Duke University neurologist Erich Jarvis thinks we have a lot more in common with songbirds than first meets the ear. He's been studying bird brains and comparing them with ours.

ERICH JARVIS (Duke University): The basic similarity between songbirds and humans is that we both have cerebral brain areas that control learned vocal behavior.

CHAD COHEN: So, if you look at the cerebral areas of my brain, for example, this area back here helps me understand the words I hear. Whereas, a little bit further up, this area helps me produce the actual words. It's taking no less then 100 muscles, by the way, just for me to be telling you this. And before I can utter a single word, that word-understanding area and that word-producing area need to talk to each other through some sophisticated circuitry.

A songbird's brain also has areas that process and produce sound, and these areas are also connected through sophisticated circuitry.

JUAN URIAGEREKA: For an organism that is so distant from us, that's quite remarkable. Nature is playing a very slick trick, right there.

CHAD COHEN: A trick that Dr. Santosh Helekar is using to help unravel the mystery of speech. He's exploring a troubling speech disorder...

DENNIS (Speech Therapy Patient): I love to, to, to, to, to, to...

CHAD COHEN: ...stuttering, a condition that causes patients, like Dennis, to get stuck on syllables. Believe it or not, Santosh thinks that some of his zebra finches have a similar problem. Yep, it appears songbirds stutter, too.

SANTOSH HELEKAR (Baylor College of Medicine): A normal birdsong of a zebra finch consists of a sequence of syllables that are repeated over and over again.

CHAD COHEN: This is the sonogram of a normal zebra finch song. A simple melody, consisting of several syllables repeated over and over again. But Santosh's stuttering birds sing like this.

They get stuck on one syllable and keep repeating it over and over again, not unlike what's happening to Dennis.

HENNING VOSS (Weill Cornell Medical College): Hi, Santosh. How are you?

SANTOSH HELEKAR: Hi, Henning. How are you? I brought some birds.

CHAD COHEN: To find out why, Santosh, along with colleague Henning Voss of the Weill Medical College of Cornell, decide to scan the brains of these pint-size stutterers.

To do it, they have to adapt an fMRI machine, designed for a human brain, to scan one a lot smaller. Henning creates this coil to do the job.

Once the tiny patient is mildly sedated, it's put inside the coil and into a soundproof box, equipped with headphones. Then bird, box and all, are placed into the fMRI and the scanning begins.

HENNING VOSS: We will see the brain from the side.

CHAD COHEN: They soon pick up a signal.

HENNING VOSS: This is the forebrain, the cerebellum. Here, one can see midbrain and spinal cord coming out, and the beak.

CHAD COHEN: Now it's time for the entertainment portion of our program.

The tiny patient is played a familiar melody, the song of its father, who first taught him how to sing.

As it listens, the scanner picks up increased blood flow in the part of the brain used to process sound.

HENNING VOSS: Okay, we have very nice activations...

SANTOSH HELEKAR: ...smack in the middle of the hearing center of the brain.

CHAD COHEN: The scans show nice activation, but when they compare the results of these stuttering birds with scans of normal birds, they find a difference.

SANTOSH HELEKAR: A stuttering bird's brain doesn't have the same pronounced activation as a normal bird has.

CHAD COHEN: And here's where it gets really interesting. It turns out, similar activation patterns are found in human stutterers. Stutterers have less activity in an area of the brain used to process sound than normal speakers do.

This connection between human brains and bird brains poses yet another question for researchers: how did two distinctly different species end up with, not only intriguingly similar vocal learning systems, but similar speech disorders? The answer may lie in our genes.

Back in the 1990s, researchers found a genetic link to language, when they discovered an English family suffering from a rare speech disorder.

INTERVIEWER: Where do you live Laura?

LAURA: (inaudible)

ROBERT C. BERWICK (Massachusetts Institute of Technology): This family had extreme difficulty with vocalization, moving their mouths around the right way, with putting the sounds in the right order.

CHAD COHEN: Genetic studies revealed a single gene mutation was the cause. The faulty gene, called FOXP2, was christened "the language gene."

ERICH JARVIS: That discovery prompted myself and Constance Scharff, a longtime collaborator of mine, to examine whether or not something was similar in songbirds.

CONSTANCE SCHARFF (Free University of Berlin): Do birds have the FOXP2 gene? Because that wasn't clear at the time.

CHAD COHEN: Well, they not only found the FOXP2 gene in birds, they discovered how it influences the way a bird learns to sing.

ERICH JARVIS: When the young birds are learning how to imitate songs, the FOXP2 gene was going up.

CHAD COHEN: This enabled cells to produce more protein.

ERICH JARVIS: And after learning was complete, it went down. Not only that, we found that in canaries, who can continue to learn song throughout life, at the time of the year they're learning to imitate new songs, the FOXP2 gene goes up again.

CHAD COHEN: An amazing discovery that brings with it a whole other set of questions. FOXP2 is found in just about everything from fish to yeast.

CONSTANCE SCHARFF: Even in flies and bees. So it's not the gene that makes us speak. It's a gene that is being used in many neighborhoods.

CHAD COHEN: Erich Jarvis, for one, is committed to figuring this out. He's set his sights on identifying other genes that may hold the key to why we can speak, birds can sing and others, even our closest relatives, cannot.

It's not for lack of communication skills. Since the 1970s, researchers have demonstrated that chimps understand our words and can even answer back.

ERICH JARVIS: Chimps have this ability of sign language. They already have language with the hands, they just can't do it with the voice.

CHAD COHEN: Jarvis theorizes that a few unknown genes give us something the chimps don't have, that neural circuitry connecting the word-understanding area of our brain to the word-producing area. Without this circuitry, he surmises, chimps can't speak.

ERICH JARVIS: It's not such a crazy idea to think that a few genes have to be mutated to get such a system in the brain.

CHAD COHEN: A system that gives us the gift of gab and our feathered friends inspiring melodies.

JUAN URIAGEREKA: I love these little guys, but now doubly so, because they're a model organism. We can seriously study them.

CHAD COHEN: Whether it's through words or song, one thing's for certain. We aren't the only ones with something to say.

TRAINER: How about a chimpanzee?

EINSTEIN: Ooh, ooh, ooh, ooh, ah, ah.

On Screen Text: Meet Hubert and Mabel Frings. In the 1950s they recorded French Jackdaw crows. The Frings played those same French crow calls to American crows that never migrated, and they didn't understand them. But when they played those same French calls for American crows that did migrate, they understood!

Conclusion? "This means that the reactions to the calls are at least partly learned by the crows and are not strictly inborn."

PROFILE: LONNIE THOMPSON

NEIL DeGRASSE TYSON: Most people, if they're packing for a trip to the tropics, they're thinking, "Beach, palm trees...so I'll bring the bathing suit, the flip flops." But guess what? The tropics are more than beaches. In fact, they have glaciers, ice, covering huge mountain ranges.

In this episode's profile, we meet a scientist who loves the tropics, but whenever he goes, he's packing a parka and a giant ice pick.

Why would this 60-year old scientist put himself through this: 33 years of grueling treks, punishing altitudes and frigid temperatures?

MARK BOWEN (Author, Thin Ice: Unlocking the Secrets of Climate in the World's Highest Mountains): Lonnie has spent more time above 18,000 feet than any human in history.

NEIL DeGRASSE TYSON: Is he a thrill-seeker?

LONNIE THOMPSON (The Ohio State University): Uh, no, I'm very much not a thrill-seeker.

NEIL DeGRASSE TYSON: So why has he scaled remote tropical mountains in 15 countries on five continents for more than 30 years? Glaciologist Lonnie Thompson is after this: ice cores.

RAY BRADLEY (University of Massachusetts Climate System Research Center): Lonnie reminds me of Clark Kent, that Superman character, where, at home, he's mild-mannered, and then, suddenly, he learns about an ice cap that has an interesting record, and he tears off his shirt, and he suddenly becomes "Tropical Ice Core Man."

NEIL DeGRASSE TYSON: Lonnie makes these harrowing treks because he knows that the ice cores he drills contain significant data about climate change.

LONNIE THOMPSON: That's really what I like about ice. There are so many different questions that you can address by reading the history that is recorded in the ice fields of the world. Unfortunately, that history is melting in today's world.

NEIL DeGRASSE TYSON: Which is why Lonnie is a man with a mission. Global warming is melting glaciers around this planet at an accelerating pace. That is exactly what's happening to this ice cap in Peru, the place where Lonnie's career really took off.

It was here, at the Quelccaya Ice Cap, in the 1970s, that Lonnie began to pioneer a new scientific discipline: tropical alpine paleoclimatology, the study of climate history using tropical mountain glaciers.

As a young scientist, it occurred to Lonnie that tropical ice cores might provide climate information the poles could not.

LONNIE THOMPSON: We need to understand some other processes, like El Niños and monsoons. You know, you can't, you wouldn't go to the polar regions to capture those, those are tropical phenomenon.

NEIL DeGRASSE TYSON: With Quelccaya and his other glaciers disappearing fast, Lonnie's archive at Ohio State University may soon be the only place to find tropical ice.

He and his team have amassed four miles of it, an archive of global climate history dating back 700,000 years. It almost looks like reading tea leaves, but, in fact, the ice is chock full of microscopic data for Lonnie's team to analyze.

Annual layers of ice collect dust particles, bubbles of gas, bacteria, pollen and other clues. From this information, the team forms a picture of a slice in time.

When they compare records from around the world, from long before the Vikings through the Industrial Age, they can create a timeline that tells the climate story of our planet.

LONNIE THOMPSON: And it's amazing that the ice is such a fantastic recorder of these, that you can actually see the increase in things like sulfate rising through industrialization. But you can also see the passage of the Clean Air Act in 1970 and the reduction in sulfate, after that.

NEIL DeGRASSE TYSON: Though the stakes may be higher today, Lonnie's fascination with the earth's climate began when he was just a kid in Gassaway, West Virginia. One of Lonnie's science teachers loaned him equipment to build a weather station, which he set up in his sister's horse barn.

REGINA THOMPSON-BOBO (Lonnie Thompson's Daughter): I think, well, "What was I doing at that age?" You know? Listening to music and thinking about M.T.V., and I just picture my dad, like, in the top of a barn figuring out what the weather is going to be, I think it's pretty neat.

NEIL DeGRASSE TYSON: Scientific curiosity seemed to come naturally.

LONNIE THOMPSON: I ran an experiment when I was in high school, how long I could stay up without sleep. Because there were stories that if you stayed up, you know, past 70 hours, you'd start seeing pink elephants and things like that. And it wasn't true, but I tried it out to find out.

NEIL DeGRASSE TYSON: Lonnie's mom and dad were insistent that he do something they never could: go on to college and graduate school.

FRANCES THOMPSON (Lonnie Thompson's mother): You have to have hope. There was a lot of times our meals were pretty skimpy, you know? And I never allowed them to complain. I said, "Now, don't say anything. It could be worse." Although, at the moment, I didn't know how it could be worse.

NEIL DeGRASSE TYSON: Lonnie worked four jobs through high school, an effort that became more important after his Dad died from a heart ailment. Just two years later, he lost his sister to a car accident.

LONNIE THOMPSON: It really brought home, at an early age, the fact that we have no guarantee of how long anyone's life will last. If you want to do something, you need to get on with it, because the clock's ticking.

NEIL DeGRASSE TYSON: Happily for him, Lonnie met a plucky fellow scientist who shared his stamina: Ellen Mosley.

ELLEN MOSLEY-THOMPSON (The Ohio State University): Well, I thought he was attractive. He seemed very serious. And then after we met, I found out that he had lots of humor, and we liked a lot of similar things like scary stories, scary movies.

NEIL DeGRASSE TYSON: In the 1970s, Lonnie and Ellen embarked upon the then-new study of ice cores to understand climate. Didn't take long for Lonnie to run up against a defining moment, right before one of his first presentations to peers.

LONNIE THOMPSON: One of these fellows took me aside and told me that if I got up there and told them that I could date ice core using dust, that my career was finished and done for. And it really worried me, because I respected this fellow. And I just finally said, well, "I'm pretty young, so I'm going to say what I think, and we'll let the chips fall as they may."

NEIL DeGRASSE TYSON: Scientists assumed tropical ice cores wouldn't give reliable data, because heat would melt the glacial surface, and the fresh water would trickle down and contaminate the ice layers beneath. Skeptics also thought these tropical sites were too remote and inhospitable.

LONNIE THOMPSON: So, I'm really naive about how I might do this. Probably, that worked in my favor, because I didn't know what I was getting into.

NEIL DeGRASSE TYSON: Finally, the National Science Foundation took a chance on Lonnie's plan. He and Ellen put together an international team of committed scientists and support staff. In 1979, with Lonnie's reputation on the line, the team headed to Peru.

LONNIE THOMPSON (Archival Footage): Is this the Quelccaya Ice Cap now?

MARK BOWEN: They went through this amazing experience in the back country, for three months. They ran out of food twice, they were eating, you know soup, made of orange peels and the old coca leaves; it was very risky in many ways. And then they had this miraculous success.

The Quelccaya ice core reached back about 1,500 years. It was an amazingly precise record. You could see when there were droughts, you could see when there were big El Niños. Little tips in climate can have disastrous implications.

NEIL DeGRASSE TYSON: Lonnie's efforts reveal that this glacier, on Quelccaya, is typical of the tropics. It's receding, and his team has documented that process over decades.

When Lonnie started, there was no lake here.

LONNIE THOMPSON: In the first 15 years it was retreating at about six meters per year, and the last 15 years, it's been over 60 meters per year. So that's a tenfold increase in the rate of which the ice is being lost in this valley.

NEIL DeGRASSE TYSON: But his research is not all that's put Lonnie on the map. It's his ability to see and communicate the implications of his findings.

LONNIE THOMPSON: When you go into the tropics, you've got 70 percent of the 6.5 billion people living on the planet living there. And when you go to a country like Peru, where 80 percent of its water comes from the glaciers that produces the power for the country, the loss of that archive becomes a human issue. That water is also used for irrigation, municipal water supplies, and it's all disappearing.

It's not so much what we know—though that's going to be very important in dealing with these problems—but it is more the human spirit that we can when we—at least when we have to—work together to do something.

NEIL DeGRASSE TYSON: Now, four decades after his start, Lonnie has been given the highest recognition for his lifetime of achievement.

ANNOUNCER (Film Clip): Lonnie G. Thompson.

NEIL DeGRASSE TYSON: He's been awarded the National Medal of Science in acknowledgement of his research and his public impact.

ANNOUNCER (Film Clip): ...National Medal of Science for his primary research.

LONNIE THOMPSON: I go back, and I think about my childhood growing up in West Virginia. And you think about all the choices that you make along the road that take you in a certain direction, even if you had known, you know, how is it possible that you would make all these particular choices? Sometimes when I look at it, I think it's kind of a miracle.

On Screen Text: Lonnie has about as much ice in his freezer as there is on the Rockefeller Plaza ice rink. Thing is, he had to get it down from here.

Just saying.

COSMIC PERSPECTIVE – LCROSS: THE SEARCH FOR WATER

NEIL DeGRASSE TYSON: And now for some final thoughts on the search for water.

Water, of course, is not just a refreshing beverage. It's got some other useful properties too. You remember that its chemical symbol is H2O. That's one oxygen bound with two hydrogen atoms. The water molecule is remarkably stable, but with a large investment of energy, you can separate the atoms from each other.

Now, suppose you were an astronaut exploring the surface of another planet that you knew, in advance, had lots of water. That'd be good, because, apart from drinking the stuff, once you split the molecule, you'd now have oxygen to breathe. Not only that, if you bring the oxygen back together with the hydrogen, making water once again, then large amounts of energy will spew forth, equal to the energy it took to break the molecule apart in the first place. It's this reaction that powers the main engines of the space shuttle.

So, pick a cosmic object to visit that has water, and you only need to bring enough water, oxygen and rocket fuel for the trip there. That's a huge savings in the weight of your spacecraft and in the cost of the mission.

NASA calls this "In-Situ Resource Utilization," but I'd rather call it "the filling-station model" of space exploration, allowing cosmic places to no longer be destinations but stepping-stones to the stars.

And that is the cosmic perspective.

And now we'd like to hear your perspective on this episode of NOVA scienceNOW. Log on to our Web site and tell us what you think. You can watch any of these stories again, download additional audio and video, explore interactives, hear from experts and much more.

Find us at pbs.org. That's our show. We'll see you next time.

Stay tuned for scenes from the next NOVA scienceNOW, but first...

Funding for NOVA scienceNOW is provided by the National Science Foundation, where discoveries begin. And...

Discover new knowledge; biomedical research and science education; Howard Hughes Medical Institute: HHMI.

And the Alfred P. Sloan Foundation, to enhance public understanding of science and technology and to portray the lives of men and women engaged in scientific and technological pursuit.

And the George D. Smith Fund.

And by PBS viewers like you. Thank you.

This NOVA program is available on DVD. To order, visit shoppbs.org, or call us at 1-800-PLAY PBS.

About NOVA | NOVA Homepage | Support NOVA

© | Created July 2009

Support provided by

For new content
visit the redesigned
NOVA site