NOVA scienceNOW: July 14, 2009

PBS Airdate: July 14, 2009
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NEIL deGRASSE TYSON (Astrophysicist/American Museum of Natural History): Hi, I'm Neil deGrasse Tyson, your host for NOVA scienceNOW.

You say you wish you were in better shape...

ZIYA TONG (Correspondent): Why don't you just go ahead, and I'll catch up with you later.

NEIL DeGRASSE TYSON: ...but, like this guy, you'd rather crunch your chips than your abs? Well hold onto your treadmill, because this geneticist has found a drug that's turned a couch potato mouse into a long-distance runner.

RON EVANS (Salk Institute): This mouse, we call the marathon mouse.

NEIL DeGRASSE TYSON: Exercise in a pill? How did he do it? And could it ever work for you?

Also, how did the dinosaurs really die? Was it that giant rock from space...

GEORGE POINAR POINAR (Oregon State University): Wow, Roberta, look at this.

NEIL DeGRASSE TYSON: ...or something more down to earth?

GEORGE POINAR: What we've done is to present a different theory.

NEIL DeGRASSE TYSON: The answer might be hidden in...what's this? Dinosaur poop?

KAREN CHIN (University of Colorado at Boulder): Yes, fossilized feces from dinosaurs. We actually call them "coprolites."

NEIL DeGRASSE TYSON: And in this episode's profile, you'll meet a rocket scientist who sees himself as a modern day Spock.

FRANKLIN CHANG DÍAZ: Mr. Spock is a scientist, but he also flies.

NEIL DeGRASSE TYSON: And so does this astronaut, who's been to space more than almost everybody. He's also designed a faster rocket, to boldly go where no spaceships have gone before.

FRANKLIN CHANG DÍAZ: We will have the entire solar system at our disposal. Humans will be inhabiting space in a big way.

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.

MARATHON MOUSE

NEIL DeGRASSE TYSON (Exercising): Everybody knows exercise is good for you: it's great for your heart, good way to stay trim. Some people just love doing it.

(Sitting): But for others, it's just too hard. There's all that trouble, all that sweat.

(Exercising): Then, of course, there are people who can't exercise, because of illness or injury.

Correspondent Ziya Tong met some researchers who have discovered a drug that may someday allow those people to get the benefits of exercise without having to do the work.

ZIYA TONG: When I watch something like the Boston Marathon, I'm blown away. These people are like Energizer Bunnies^®: they keep going and going. And they're so lean!

How do they do it?

They'll all say, "By training." But what if you could skip all that? What if there were a drug that could miraculously give even the laziest slob a lean, buff bod, and turn them into an endurance athlete? It sounds like the ultimate couch potato fantasy.

Well, it's no fantasy to this guy. Ron Evans, from the Salk Institute, figured out the secret formula and gave the magic potion to a mouse. And just like that, a couch potato mouse was transformed into a real marathoner.

It all started with Evans's fascination with endurance. Only some animals have it. Horses have endurance and so do migratory birds, but our closest relatives, all the other primates, don't.

RON EVANS: In fact, humans are the only primates that have endurance. You don't see gorillas going on marathon runs, and the other primates aren't really designed for long distance running. Humans are designed to be good runners if we want to be good runners.

ZIYA TONG: Glen Mays is a good runner.

GLEN MAYS: I've been running for a very long time. I started when I was a young kid, and I had, kind of, a knack for it.

ZIYA TONG: Glen has such a knack, he won the Little Rock, Arkansas, marathon.

Are you tired yet?

GLEN MAYS: No, not yet.

ZIYA TONG: And me? Not so much knack.

Why don't you just go ahead, and I'll catch up with you later.

Of course, Glen works much harder than I do.

GLEN MAYS: You spend a lot of time just getting in the miles and doing long runs and being on your feet for 90 minutes, two hours, two and a half hours.

ZIYA TONG: And all that effort has changed Glen's muscles.

There are two main kinds of muscle. Folks like this build up the bulk with what's called fast-twitch muscle. It contracts fast and strong, and gets its energy from a particular kind of fuel source: sugar.

RON EVANS: Most muscle likes to burn sugar, so power muscle burns sugar.

ZIYA TONG: But if you could look inside the body of someone with endurance, say, inside the legs of Glen Mays, you'd see slow-twitch muscles. These can keep going for much, much longer because the fuel they burn is something much higher-octane than sugar.

RON EVANS: Endurance muscle burns fat.

ZIYA TONG: When it comes to fat, a little bit provides a lot of energy. Most people can train their bodies to burn more fat, but they've got to work at it.

RON EVANS: Exercise is what usually promotes that fat-burning, but we don't get enough exercise. So we wanted to see if we could actually trigger the process, even in absence of exercise.

ZIYA TONG: So Ron Evans went on the hunt for a way to rev up the fat-burning in a muscle without making it exercise.

He homed in on a key gene, one that can turn on lots of other genes.

RON EVANS: We're looking at a master regulator. It is sort of a genetic switch. If you're able to switch it on, you will activate a network of genes that allows you to burn fat.

ZIYA TONG: Evans figured out how to turn on this fat-burning genetic switch inside a mouse embryo, so it would work in overdrive. And then he watched the genetically-engineered mouse grow up. It was definitely more svelte.

RON EVANS: And, indeed, the mouse that was generated from that does burn more fat. It's slightly thinner, and we liked the way in which the mouse was looking.

ZIYA TONG: But this mouse was a lot more than good looking.

RON EVANS: If you put it on a treadmill, it can run the pants off of any other mouse. And so while the other one had been exhausted, thrown back off the treadmill, this mouse was running for another hour. And this mouse, we call the marathon mouse.

ZIYA TONG: By manipulating just one genetic switch in the embryo, Evans created a mouse with fantastic endurance. How's that possible?

It turns out, the switch Evans turned on set off a chain reaction that directed the mouse to make more slow-twitch muscle. Slow-twitch muscle is especially packed with things called mitochondria. Mitochondria are little factories inside our cells that turn sugar and fat into energy. And in the marathon mouse, the mitochondria were burning more fat than usual.

The mouse's muscles and metabolism were completely transformed, as if this little guy had been exercising his butt off, all because Evans turned on one little switch in the mouse embryo.

A mouse that could run almost twice as far as an ordinary mouse made science headlines and had very interesting implications for people. After all, who wouldn't want the ability to run that extra mile? The problem was, these mice were programmed, as embryos, to be superstars, and we don't do that to human beings, at least not yet. So Ron Evans started searching for a drug that could activate that same marathon gene. But as he soon found out, it's not that easy.

When Evans tried to use a drug to turn on the fat-burning gene in an already-grown-up mouse, it didn't really work. He got a mouse that didn't run any better than average.

So Evans took a closer look at what happens inside our muscle cells whenever we give them a workout.

ROGER FIELDING (Tufts University School of Medicine): As you become more and more trained, the muscle actually starts making more mitochondria and also making them larger, so that they can actually process and break down more fuels for energy.

ZIYA TONG: So how does exercise tell our muscles to make more mitochondria?

Evans saw that, during exercise, as energy gets consumed, certain chemicals build up in the muscle cells and trigger the cell's molecular fuel gauges. When energy gets too low, they'll signal the cell to make more mitochondria and pump out more energy.

RON EVANS: It's like the fuel gauge: we are getting on to low, we are getting near empty, let's get the gas back in the tank.

ZIYA TONG: Evans decided to try a drug called AICAR that he believed would, in effect, break the fuel gauge, tricking the muscle into thinking it was running on empty, even when it wasn't running at all.

So Evans got together some mice and didn't exercise them one bit.

RON EVANS: Completely couch potato mice, all watching T.V., none of them getting any exercise, and one of them was getting the AICAR drug.

ZIYA TONG: AICAR was injected into the mouse's bloodstream, five days a week, for a month, and when this couch potato mouse got on the treadmill, the results were amazing.

RON EVANS: That turned into a spectacular result. The ones that received AICAR were able to run approximately 44 percent longer distance.

ZIYA TONG: In fact, this drug-enhanced couch potato mouse ran nearly a mile. That's almost like running a whole marathon for you or me.

And when Evans took a look inside the mouse's muscle cells, the difference the drug made was striking.

Look at the normal mouse's cells; the mitochondria show up as dark spots. But look at the mouse that took AICAR; tons more mitochondria.

RON EVANS: This looks like the muscle of an athlete.

ZIYA TONG: This one drug managed to break the fuel gauge and trick the muscle into turning on its endurance genes, pushing the muscle into overdrive.

RON EVANS: It's remarkable that the benefit of exercise alone and the benefit of the drug – almost exact.

ZIYA TONG: That's right. In totally sedentary mice, Evans's drug produced results identical to regular exercise.

At this point, you might be wondering, "Where can I get some?" Well, it's a bit too soon for us humans to be taking this. Though the mice didn't develop side effects, nobody really knows how it will affect people.

But if it could be used safely, doctors are hopeful it could be a valuable therapy for people who can't exercise, especially for the old and frail, who can lose muscle at an alarming rate.

WILLIAM J. EVANS (University of Arkansas for Medical Sciences): Ten days of bed rest is equivalent to about 15 years of aging. And so, oftentimes, we see someone who is fully functional go into a hospital and five or six days later they come out of the hospital hardly able to walk. A drug like this, if it helps to restore function in older people, it may make it a lot easier for them to become active, and that would be fantastic.

ZIYA TONG: Ron Evans would love to see people benefit from what could be exercise in a pill, but one major concern is how this drug might be abused, especially by athletes.

RON EVANS: Athletes have a very low threshold for looking at performance-enhancing drugs, and their real concern is not about the drug, it's whether it can be detected.

ZIYA TONG: Evans has developed a test to trace AICAR in the bloodstream, to discourage doping. But even if AICAR gets out there, Glen Mays says he's one athlete who won't be taking it.

Well, if there was a drug that, perhaps, you could take that would allow you to run further, would you take it?

GLEN MAYS: I don't think I would. I don't think I would. For me, the interest and the challenge is in seeing what I can accomplish through my training. That's what keeps you motivated, and a big part of distance running is staying motivated to get out there every day and do the training.

ZIYA TONG: He's going to stick with the old-fashioned way of improving his endurance. After all, that's the one way we know definitely works. Maybe we all should try it sometime.

On Screen Text: Know what the derivation of the word "muscle" is? "Muscle, noun, origin: French, from Latin musculus diminutive of 'mouse.'" Yes, "muscle" comes from the Latin-based word "musculus," meaning "little mouse."

Why?

"Origin: So called because the shape and movement of some muscles (notably biceps) were thought to resemble mice moving beneath the skin."

DINOSAUR PLAGUE

NEIL DeGRASSE TYSON: Ever since we've known dinosaurs once walked the earth, we've been debating about what could have killed them off. There've been a lot of ideas kicked around over the years, like global climate change caused by shifts in the earth's axis or a series of monster volcanoes. And for the last 25 years, the most popular idea has been that dinosaurs were wiped out by a giant rock from space, an asteroid that created devastation on a global scale.

But as correspondent Chad Cohen reports, not every scientist is ready to blame just the rock. Some believe the giant reptiles might have been taken down by something almost too tiny to see.

CHAD COHEN (Correspondent): At the Poinar residence, in Corvallis, Oregon, the workday starts early. At least, it does for George.

ROBERTA POINAR: He's up with the dawn, he goes down in his socks or his slippers, sneaking, so he won't wake me up.

CHAD COHEN: As he makes his way downstairs, to his homegrown lab in the basement, he's bent on finding things that no one else has even looked for.

ROBERTA POINAR: He gets up in the morning to make discoveries.

GEORGE POINAR: Oh, wow, Roberta come look at this. It's the...

ROBERTA POINAR: He's just like a kid, that everything is new and wonderful.

CHAD COHEN: For decades, George and his wife and colleague, Roberta, have bucked the trends in mainstream science, painting a novel picture of life in the ancient world. Preserved in pieces of amber, they've discovered insects, flowers, even tiny animals, all trapped in time.

If this sounds familiar, it was their work that inspired Jurassic Park, in which scientists use amber to, literally, bring the dinosaurs back to life.

SAM NEILL (As Doctor Alan Grant in Jurassic Park/Film clip): It's a dinosaur!

GEORGE POINAR: The movie depicted a mosquito that had actually been caught in resin, and then fossilized into amber. And that's scientifically correct, because amber preserves things so beautifully.

CHAD COHEN: Scientifically correct, at least, until Jurassic Park scientists discover something no real scientist had ever found before: a 100-million-year-old mosquito trapped in amber, with dino blood in its gut. They use it to re-create the mighty creatures.

GEORGE POINAR: This is a movie, this is a film, this is Hollywood. They can do whatever they want. That'd be neat if we could actually do it.

CHAD COHEN: And to date, only Hollywood can.

But then, in 2001, George received an unusual package by special delivery, a one of a kind piece of amber, containing a bloodsucking insect, a lot like the one in Jurassic Park.

Rather than using this extraordinary specimen to resurrect the dinosaurs, he believes it could help reveal what caused their demise.

Most scientists theorize that dinosaurs died out suddenly, in a fiery explosion caused by an asteroid, but not George. He believes by the time of the impact, most of the dinosaurs had already died.

You ask a scientist these days and they'll say a giant rock struck Earth 65 million years ago, somewhere around the Yucatan, and did in the dinosaurs. But you're not buying that?

GEORGE POINAR: Well, the thing is that most people have kind of jumped on the bandwagon for the asteroid theory, and what we've done is to present a different theory.

CHAD COHEN: Based on what he's found trapped in amber, George believes the mightiest of creatures—the dinosaurs—were brought down by the tiniest of creatures—biting, disease-carrying insects.

His first clue was found in that special delivery.

GEORGE POINAR: We got the specimen, put it under the microscope, saw it's a sandfly. So we went to the next objective, magnified it a little bit and then, "Oh, I see there's some dark substance in the abdomen."

CHAD COHEN: In all his years he'd never seen anything like this. It appeared as if the sandfly's last meal was still trapped inside its tummy. It looked an awful lot like blood. He asked Roberta to take a look.

GEORGE POINAR: When I first showed her that, she said, "Well, you'd better make sure that that's blood."

We've got some more work to do here.

ROBERTA POINAR: Yep, you have your job cut out for you.

CHAD COHEN: The only way to find out was to get a closer look. That meant cutting away the amber around the sandfly. It's very tricky business. In the process he could easily destroy the tiny fossil and maybe lose a finger, too.

After each cut, he polished and carefully examined the specimen.

ROBERTA POINAR: You have to spend hours and hours and days and weeks and months turning the same specimen over.

CHAD COHEN: Searching for the best angle to get a glimpse of what's inside.

ROBERTA POINAR: You're looking through multiple layers of tissue and you have to find that window.

CHAD COHEN: By cutting the amber down to within one millimeter of the sandfly, George found the window he needed to see this: blood cells from what appeared to be a reptile.

The discovery made him think.

GEORGE POINAR: If these sandflies are feeding on reptiles, certainly the dinosaurs would have been included.

CHAD COHEN: While blowing up photographs of the sandfly, using an enlarger about as ancient as his amber, he made another astonishing find.

GEORGE POINAR: Wow, look at that!

CHAD COHEN: This was no blood cell.

GEORGE POINAR: Roberta.

CHAD COHEN: George found a microorganism inside the fly.

ROBERTA POINAR: Oh wow, that's amazing.

CHAD COHEN: But what was it? Consulting with experts around the world, he identified it as a deadly parasite called Leishmania that's still around today, killing thousands of people every year. And it's spread by sandflies.

Over the next few months he found more evidence: ten fossilized insects carrying the same deadly parasite. Then he found this: a midge with malaria and another one carrying the parasite for sleeping sickness, all deadly infectious diseases.

ROBERTA POINAR: How could this be? There was an epidemic going on, a whole epidemic. The dinosaurs were probably pretty sickly.

CHAD COHEN: The Poinars believe their evidence points to widespread disease among the dinosaurs, but if there was, in fact, an epidemic going on, that's challenging to prove. We don't exactly have dinosaur tissue to do autopsies, and bones can only tell us so much.

ROSS MACPHEE (American Museum of Natural History): They suffered, just like we do, from things like osteoarthritis. There's much less evidence of infectious disease; it's not going to leave impressions that paleontologists can find on bone.

CHAD COHEN: They did however leave behind another less-appreciated memento that could yield some clues about the state of their health.

So you're telling me this is fossilized dinosaur poop?

KAREN CHIN: Yes, fossilized feces from dinosaurs. We actually call them coprolites...

CHAD COHEN: Coprolites?

KAREN CHIN: ...which is the scientific word for fossilized feces. Not necessarily dinosaur. But these, this is dinosaur.

CHAD COHEN: This is dinosaur.

Not many coprolites survived the ages, but in Jurassic Park, the fresh stuff was easy to find.

To put this in perspective...a male elephant, the largest land animal alive today, weighs in at about 6.5 tons and he voids, on the average, about 22 pounds, 17 times a day. That's over 300 pounds in 24 hours; not a pretty sight.

Now take that image and exchange it with this, a sauropod, and he's up to 15 times heavier than the elephant. It's hard to imagine how much dung this giant dumped.

KAREN CHIN: When we look at pictures of dinosaurs we often see them tromping through really pristine fields. Actually those fields probably would have been littered with dinosaur dung.

CHAD COHEN: Piles of poop, swarming with insects and, likely, swimming in pathogens. And that's an environment that, today, would potentially cause disease.

KAREN CHIN: Yes, I have no doubt that the dinosaurs did get sick.

CHAD COHEN: While Karen's coprolites don't show evidence of the deadly parasites George and Roberta discovered in ancient amber, she, along with graduate student Justin Tweet, did find this.

KAREN CHIN: You see these lines here? Justin found about 200 of these very distinctive tiny burrows.

CHAD COHEN: Burrows, Karen believes, may have been made by worms. There's a thought: dinosaurs with stomach worms.

GEORGE POINAR: I think the dinosaurs were carrying all kinds of pathogens with them.

NATHAN WOLFE (University of California, Los Angeles): They had parasites, they had bacteria, lots of viruses. Without a doubt, microorganisms impacted the day-to-day lives of dinosaurs.

CHAD COHEN: That's not exactly a surprise; everything carries microorganisms, from worms to bacteria to viruses. We, too, host a multitude of guests that use us as a source of food and shelter. Most of the time, we peacefully co-exist, but as we all know, microorganisms can sometimes make us sick.

But could they have caused the downfall of hundreds of species of dinosaurs?

NATHAN WOLFE: It's unclear that we've seen the ability of any microorganism—viral, bacterial or otherwise—to have that level of impact.

ROSS MacPHEE: Until recently nobody was thinking that extinction could be caused merely by disease. That's changing.

CHAD COHEN: In fact, some scientists think there's a perfect example of it taking place today, right before our eyes.

Zoologist Andrew Blaustein, of Oregon State University, took me to a tiny pond, so I could see for myself.

ANDREW BLAUSTEIN (Oregon State University): The scale is unbelievable. It's worldwide, and it's similar to the dinosaur extinctions, except it's happening in modern time.

CHAD COHEN: And this time, it's happening to amphibians. Frogs, toads and salamanders are disappearing at an alarming rate. Since the 1970s, over 100 species have gone extinct.

ANDREW BLAUSTEIN: They are in trouble, big trouble.

CHAD COHEN: And one of reasons is the spread of infectious diseases.

ANDREW BLAUSTEIN: Here's the perfect example. Here you see a little frog—this is a tree frog—and these things are getting infected by all kinds of diseases. In the same body of water where I just picked this guy up, there are these snails. That snail carries a parasite that infects that frog.

CHAD COHEN: Andrew and I were often interrupted by another example.

ANDREW BLAUSTEIN: You hear that bullfrog out there? This is not a native species to the western United States, and it carries a deadly fungus known as the chytrid fungus, and the native species right here in this pond and lake can get that fungus. As a matter of fact, every single bullfrog that we find in this area has been infected, but they don't get sick, they just carry it.

CHAD COHEN: The bullfrog, like the snail, is a new resident in the pond. And the parasites they carry are seen as invaders by the tiny tree frog's immune system.

ANDREW BLAUSTEIN: This is what George Poinar is talking about. Well, we're seeing the same thing here today. I don't think George went far enough. I think it's a lot of diseases and not just diseases that come from biting insects. And I think he'd agree.

CHAD COHEN: Graduate students Julia Buck and Catherine Searle take swabs off a tiny tree frog's belly to check for the deadly chytrid fungus. So far over 30 percent of the tree frogs are infected.

But even Andrew doesn't believe this extinction event is caused by disease alone. Environmental changes, like global warming and pollution make animals more susceptible to getting sick.

ANDREW BLAUSTEIN: It may not be an overt disease that kills these things. These things can have multiple insults that really mess up their immune systems.

CHAD COHEN: And we can apply that to what might've happened to the dinosaurs 65 million years ago?

ANDREW BLAUSTEIN: There were massive global changes, global climate shifts. Those could have triggered disease events.

CHAD COHEN: Just like the tiny tree frog, the mighty dinosaur's world was changing, from radical shifts in ocean temperature, to an increase in volcanic activity, to an explosion of flowering plants that nourished a growing insect population. More biting insects, according to the Poinars, meant new deadly diseases being carried to a species already struggling to adapt to change.

GEORGE POINAR: When any population is stressed, diseases emerge and can run rampant. These would have been completely new diseases that the dinosaurs didn't know about before, didn't have any experience with, and they wouldn't have had any immunity to them.

CHAD COHEN: We may never know if the Poinars' theory is right, but one thing is for certain, they've brought us closer to the fantasy world of Jurassic Park than any other scientists, and promise to keep the discoveries coming, all from the comfy confines of their basement.

ROBERTA POINAR: We believe that insects—little, tiny sandflies and ticks and mites, and everything—were feeding on those dinosaurs. So that really puts insects at the top of the food chain.

GEORGE POINAR: Oh, Roberta, take a look at this. It's a biting midge, and you can see the eyes and the mandibles, as well.

ROBERTA POINAR: Oh, that's really fantastic! Look at those mandibles. They could get a good bite out of something, maybe even a dinosaur.

GEORGE POINAR: Maybe so.

On Screen Text: Here's a timeline: Dinosaurs first appeared 230 million years ago, went extinct 66 million years ago, but there's life that came before them, still around today: dragonfly, 250 million years ago; coelacanth, 410 million years ago; horseshoe crab, 445 million years ago.

And where do we fit in? Humans, about 2 million years ago. Humans. Ha!

PROFILE: FRANKLIN CHANG DÍAZ

NEIL DeGRASSE TYSON: A lot of us are hoping that someday soon, people are going to board a spaceship and travel to Mars, which, on a good day, is at least 40 million miles away.

Right now, that trip takes about seven months, each way. But since there's no filling stations or places to go shopping en route, that means you've got to pack your ride with at least 14 months of supplies.

But what if you built a spaceship that could go much faster, and make the round trip in about three months? Well, in this episode's profile, we meet a rocket scientist who thinks he knows how to do it. And his new rocket could shave months off a commute to the Red Planet.

Franklin Chang DÍaz loves watching Star Trek with his wife and youngest daughter.

FRANKLIN CHANG DÍAZ: I've been a Trekkie since I came to the United States. We watch the episodes over and over and over again.

MIRANDA CHANG DÍAZ (Franklin Chang DÍaz's Daughter): My dad kind of passed this rule that we can't watch it without him.

NEIL DeGRASSE TYSON: Franklin's favorite character? Mr. Spock.

FRANKLIN CHANG DÍAZ: He has a very important position of leadership in his crew. Mr. Spock is a scientist, but he also flies.

NEIL DeGRASSE TYSON: Like Spock, Franklin knows a few things about being a scientist and a space traveler. He was NASA's first Latin American astronaut to go into space.

NASA MISSION CONTROL (Archival Footage): We have liftoff, liftoff of Columbia, mission 61-C.

NEIL DeGRASSE TYSON: He's been to space seven times, which ties the record. And he spent the last three decades developing a futuristic rocket engine.

FRANKLIN CHANG DÍAZ: I believe that this rocket will revolutionize space travel. We will have the entire solar system at our disposal.

NEIL DeGRASSE TYSON: Franklin's journey began in the Central American country of Costa Rica, where he dreamt of becoming an astronaut.

FRANKLIN CHANG DÍAZ: I was probably about four or five, and I took my sister, at 2:00 or 3:00 in the morning, and we climbed to the roof of our house. And we sat on the roof, eating grapefruits with sugar and looking at the stars. The sky was absolutely beautiful. I knew that among those stars there were other worlds, other places, and I wanted to be there. I wanted to go there.

NEIL DeGRASSE TYSON: His first step toward space travel? He built a rocket for his high school science fair.

FRANKLIN CHANG DÍAZ: It had a little capsule, with a small mouse and a parachute. And of course, the first stage was a complete failure and the mouse survived, which was a real triumph.

NEIL DeGRASSE TYSON: When he finished high school, Franklin was determined to become an astronaut. His father took out a loan and bought him a ticket to the United States.

FRANKLIN CHANG DÍAZ: And he said, "Look, this is all I can do for you right now." My parents never said, "It cannot be done."

NEIL DeGRASSE TYSON: With only $50 in his pocket and no knowledge of English, Franklin arrived at the home of cousins in Hartford, Connecticut. He enrolled in high school, worked hard to learn English and let everyone know he meant business.

FRANKLIN CHANG DÍAZ: I decided that I would wear a tie and a jacket every single day. And so, my teachers were, actually, a little bit surprised to see this boy coming to school with a tie and jacket, with some weird dreams about going into space.

NEIL DeGRASSE TYSON: His hard work paid off, and he won a full scholarship to college.

Within four years, Franklin had started a family and was a graduate student at M.I.T., studying nuclear fusion and developing concepts for an experimental rocket engine.

FRANKLIN CHANG DÍAZ: The idea began as a result of my Ph.D. thesis. It was clear to me that chemical rockets, the conventional rockets that we had been using all along, were not really going to give us the capability to travel far, to Mars, to Jupiter.

NEIL DeGRASSE TYSON: He was on the road to building his first real rocket, when, in 1977, NASA issued a call for a new group of astronauts. Thirty-five-hundred would apply, only 15 would be chosen. Franklin was one of those 15.

MARIA (Franklin Chang DÍaz's Mother): When he called us, I was so overcome with emotion that I yelled, "He did it! He did it!" And my husband was crying. He cried with tears, but he couldn't speak. I was the only woman in the country who was a mother of an astronaut, no one else.

NASA MISSION CONTROL (Archival Footage): T minus 20 seconds.

FRANKLIN CHANG DÍAZ: What I had prepared for, for my entire life...

NASA MISSION CONTROL (Archival Footage): T minus 12 seconds.

FRANKLIN CHANG DÍAZ: ...was actually happening.

NASA MISSION CONTROL (Archival Footage): T minus 10; go for engine start.

FRANKLIN CHANG DÍAZ: When the engines lit up, the whole thing shakes like there's no tomorrow, and you're off.

NASA MISSION CONTROL (Archival Footage): ...two, one, we have ignition; we have liftoff, liftoff of Columbia, mission 61-C. And the shuttle has cleared the tower.

FRANKLIN CHANG DÍAZ: And then, all of a sudden, everything stops. Everything floats; you're in space. Everybody rushes to look out the window, and what you see is the most beautiful thing you ever saw. And that is worth all the effort and all the trouble and all the difficulty.

NEIL DeGRASSE TYSON: Today, he shares a record for the most missions in space, and he's the most famous man in his home country of Costa Rica.

FRANKLIN CHANG DÍAZ: Viva, Costa Rica!

MIRANDA CHANG DÍAZ: It's amazing how much they react towards him. It's like he's Hercules or something.

NEIL DeGRASSE TYSON: Franklin now has privately funded labs in Houston and Costa Rica, where he devotes all of his time to testing and developing a plasma rocket engine, the same rocket he conceived of as a graduate student at M.I.T.

The testing takes place inside a large steel vacuum chamber, where the engine is fired.

WOMAN IN LAB: Pulso!

NEIL DeGRASSE TYSON: His rocket works by heating the gas argon to extremely high temperatures, until the gas changes into what's called a "plasma."

FRANKLIN CHANG DÍAZ: Typically, a conventional rocket runs at temperatures of a few thousand degrees. Sounds pretty hot, but we would like to run at temperatures of a few million degrees, temperatures like the sun...big difference.

At those temperatures, the stuff that you're shooting is going so fast that you only need little, tiny amounts of it.

NEIL DeGRASSE TYSON: That's what makes Franklin's rocket so revolutionary. It could use a fraction of the fuel used by conventional rocket engines, which could save millions of dollars in fuel costs.

FRANKLIN CHANG DÍAZ: So, you have a very small fuel tank. You can then make a tremendous rocket that way.

NEIL DeGRASSE TYSON: In 2012, for its first field test, Franklin's rocket will be fired on the International Space Station, 200 miles above the surface of the earth. If it works, his rocket may someday take the first humans to Mars.

FRANKLIN CHANG DÍAZ: If you use a conventional rocket to go to Mars, it will take you about seven months; if you use a plasma rocket, it will take you about 39 days.

NEIL DeGRASSE TYSON: Franklin imagines a future where space travel will be like Star Trek, with no limits to where we can go.

FRANKLIN CHANG DÍAZ: My dream or my vision is a future for humanity where we will have the entire solar system at our disposal. Humans will be inhabiting space in a big way. I think all human beings dream. I always tell the kids I meet to follow your dreams; it's the first thing I tell them, to not let anyone tell you that you can't do something, until you find out for yourself. I'm talking about the ability of a child to say, "Look, I want to change the world." Go do it.

On Screen Text: Question: What is plasma anyway? Answer: A gas that has been energized to the point that electrons break free from, but travel with their nucleus. Like this.

By the way, NOVA scienceNOW and plasma, we go way back. Neon-xenon plasma inside!

SPACE STORMS

NEIL DeGRASSE TYSON: Welcome back. A breaking story tonight: big storm brewing. We've got a meteorologist in the field.

Can you hear me?

(As Meteorologist): Yes. As you can see, I'm in the thick of it out here!

Excuse me, but where are you?

(As Meteorologist): I'm out in space, orbiting Earth. And believe it or not, there's some serious storms up here. And they can cause all kinds of problems down there, especially with communications systems.

...seem to be having technical difficulties.

In the meantime, check this out.

Anyone who has seen the aurora borealis, or northern lights, will tell you they're one of nature's most spectacular performances, a celestial ballet of light, dancing across the night sky.

But it turns out there's much more to this dazzling display than meets the eye, because the same thing that powers the dance of the northern lights can also wreak havoc, exposing astronauts to deadly amounts of radiation, frying electrical systems in satellites and overwhelming power grids, causing widespread blackouts.

Problem is no one has ever been able to agree on the exact choreography of events that gives rise to both this beauty and danger.

JOHN BONNELL (University of California, Berkeley): This has been one of the persistent and difficult questions to solve in space physics.

NEIL DeGRASSE TYSON: But now, an unusual space mission is aiming to solve this mystery once and for all, because figuring out what makes the northern lights dance may also hold the key to predicting these kinds of events and avoiding disaster.

The northern lights take place more than 60 miles above the Earth's surface. But they're not caused by weather on Earth. They're caused something much less familiar, called "space weather."

Now, some of you may be thinking, "Space weather? It can't possibly rain or snow in space. I mean, you don't see astronauts shoveling out the Space Station, do you?" Well, turns out space has its own special kind of weather, thanks to that big ball of glowing gas we call the Sun.

Every day, the sun spews out a million tons of electrically charged particles, which race away, at up to 300 miles per second, forming what's known as the solar wind.

Most of these particles are deflected by Earth's magnetic field, the protective shield that envelopes our planet. But some sneak through and eventually collide with air molecules.

When they hit oxygen, you get a red or a green glow; nitrogen, a blue glow, creating a steady ring of lights around the north and south magnetic poles.

But sometimes the whole process goes berserk. Huge amounts of energy from the solar wind build up in Earth's magnetic field and then are released in a sudden explosion called a substorm. And you can tell when that happens because the northern lights start to dance.

VASSILIS ANGELOPOULOS (University of California, Los Angeles): So the eruption of the aurora really corresponds to an eruption of a substorm, an energy release out in space.

NEIL DeGRASSE TYSON: But where do these violent space storms begin?

To find out, a team has launched a mission, called Themis, consisting of five identical satellites.

Wait a minute. Five satellites? Isn't that overkill?

Well, to see why they needed that many, think of a tsunami. A single buoy in the ocean can tell you if a tsunami has taken place. But if you want to figure out which way that wave is moving and how fast, you need multiple buoys, and it's the same with substorms. Except instead of buoys in the ocean, the Themis mission is using satellites.

The goal of the mission is to figure out where substorms start. And once every four days, the satellites enter the region of space where substorms occur to detect if they erupt near Earth or farther out in the magnetic field.

The Themis mission is operated at the University of California at Berkeley.

What am I looking at?

I see Earth in the middle.

MANFRED BESTER: That's right, and the five satellite orbits off to the right. This covers four days worth of orbit tracks.

NEIL DeGRASSE TYSON: And it's very clear when they all line up.

MANFRED BESTER: Exactly.

NEIL DeGRASSE TYSON: Themis is named for the Greek goddess of justice, that blindfolded lady holding the scales on courthouses. And just as the goddess weighed competing explanations to determine the truth, the Themis mission will try to determine which of two competing explanations for substorms is correct.

One theory locates the trigger for the violent release of energy relatively close to Earth; the other places that trigger much farther out in the magnetic field.

The evidence will be gathered by huge antennas on each satellite. And to see how they packed five of these into just one rocket, I paid a visit to one of the guys who designed them.

So where have you brought me? What is this place?

JOHN BONNELL: Well, so this is the mechanical engineering lab.

NEIL DeGRASSE TYSON: One antenna was designed like a high-tech jack-in-the-box. It was nicknamed "the death spike" for reasons that would soon become obvious.

JOHN BONNELL: And when I pull this string, it's going to release.

NEIL DeGRASSE TYSON: Can I give you a countdown?

JOHN BONNELL: Yes, go ahead.

NEIL DeGRASSE TYSON: Okay, ready? Five, four, three, two, one...

JOHN BONNELL: So, as you can see, about ten-foot up.

NEIL DeGRASSE TYSON: And with these antennas deployed, the team hopes the satellites will be in the right place at the right time, to catch a substorm in action.

JOHN BONNELL: It's like we've laid this trap, we've gone to the jungle, and we're waiting for the tiger.

NEIL DeGRASSE TYSON: And missions like Themis come not a moment too soon.

The sun works on an 11-year cycle, its activity level rising and falling with the number of magnetic disturbances, called sunspots, visible on the surface. Over the years, people have tried to link the sunspot cycle to everything from skirt lengths to stock prices. But the one thing we know it does relate to is space weather. And right now, we're entering a new solar cycle which will peak between 2011 and 2012.

Meanwhile, key data rests on Themis snaring a substorm, and not just any substorm: the five Themis satellites line up only once every four days in Earth's magnetic field, so the timing has to be just right.

It would be fun to be on one of these satellites, as you sort of come into alignment.

VASSILIS ANGELOPOULOS: And watch one of these auroras break up at the same time.

NEIL DEGRASSE TYSON: No, I don't want to be there for that.

It takes two days for data from the outermost satellite to download to Earth. And in previous alignments, the team's already been lucky, snaring several substorms.

VASSILIS ANGELOPOULOS: This is when three substorms took place. One took place here, the next one about an hour later, and the next one about...yet another hour later.

NEIL DEGRASSE TYSON: That's these peaks?

VASSILIS ANGELOPOULOS: These peaks.

NEIL DEGRASSE TYSON: That's the bleeding edge of the frontier of science?

VASSILIS ANGELOPOULOS: That is exactly right.

NEIL DeGRASSE TYSON: They thought it might take years, but just three weeks after I left the Themis team, the satellites discovered the smoking gun: a huge substorm that unmistakably showed where these violent releases of energy are triggered.

So which theory was right? Was it a huge energy release near Earth, or a big explosion far away?

And the verdict is: far from Earth.

It's data that will improve space weather prediction and has solved, once and for all, the mystery of what makes the aurora dance.

On Screen Text: These are the sounds of the Northern Lights. Sometimes they sing; sometimes they crackle like footsteps in the snow. Some Inuit-speaking people believe them to represent the souls of their unborn children or the torches of long-departed ancestors. Some Yup'ik believe the aurora are their ancestors dancing in the sky, a reminder that they are still with them, watching over them.

COSMIC PERSPECTIVE – NORTHERN LIGHTS

NEIL DeGRASSE TYSON: And now for some final thoughts on the northern lights.

Who would have guessed, long ago, what causes the aurora? Countless atomic and sub-atomic particles, released by the Sun, in resonance with its 11-year cycle, stream among the planets at speeds up to a million miles an hour. These charged particles see and respond to Earth's magnetic field: the positive and negative charges split north and south. They then gather and pulse, in ways still mysterious, as they collide with molecules of Earth's upper atmosphere.

The collisions render the air aglow, creating one of the most colorful and striking sights of the arctic night, as the sky fills with dancing curtains of light.

No doubt about it, the aurora is complex. To understand it requires a branch of advanced physics called magnetohydrodynamics, a field that's been known to make strong men weep.

Meanwhile, aurora has been, and continues to serve as a fertile source of art, mythology and legend, among Arctic peoples and their visitors, as it leaves viewers in silent awe of its majesty and beauty.

It's a curious thing about the universe: behind the most stunning phenomena to behold, lie some of the most challenging problems in astrophysics, from the colorful turbulence within planetary atmospheres, to stars in the throes of death, to the majestic patterns of spiral galaxies, to the large-scale structure of the universe itself.

What distinguishes the aurora among them, is that you don't need a telescope to see it, just your eyes and a ticket to the arctic.

And that's 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 audio and video podcasts, hear from experts and much more. Find us at pbs.org.

That's our show. We'll see you next time.

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