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Welcome to Cosmic Radio, a new program dedicated to exploring a different kind of astronomy... Radio Astronomy.

We’re all familiar with optical astronomy, thanks to the beautiful images produced by instruments like the Hubble Space Telescope. The Hubble Space Telescope detects light waves produced by cosmic objects. But we’re bathed by a veritable ocean of invisible waves as well, streaming in from the farthest reaches of the universe, and these waves are radio waves.

What stories do these waves have to tell? Tales of black holes, interstellar chemicals, the birth and death of stars, and an expanding universe, to name a few. These stories are revealed by scientists using radio telescopes-- gigantic instruments which resemble satellite TV dishes more than anything else.

For centuries observations of the universe were confined to the visible part of the spectrum. People charted the positions of the stars and the motions of the planets using nothing but their eyes. Then, simple telescopes were invented and a whole new era of discovery came into being. Centuries later, radio telescopes would open yet a new window to the universe.

People produced radio waves and used them for communication well before they were discovered in space. KDKA, the first commercial radio station, went on the air in 1920. 10 years later, a young physicist named Karl Jansky made a surprising discovery when he detected radio signals coming from the center of our galaxy, a kind of ...cosmic radio... if you will. And a new science was born.

We hope you enjoy the stories of astronomical discoveries and the people who made them over the coming months. We invite you to tune into the universe with Cosmic Radio.

To learn more, visit the National Radio Astronomy Observatory website, at www.nrao.edu.

"; fullScripts["02"] = "

While humans have been studying the stars since pre-historic times, radio astronomy is a comparatively new science. Its birth came with the accidental detection of a radio signal emanating from the center of our galaxy.

In 1930 Bell Laboratories was considering a short-wave transatlantic phone system. They hired Karl G. Jansky to uncover potential problems with such a system. In particular, they worried about static caused by thunderstorms. 

Jansky constructed a large directional antenna on a sort of merry-go-round, so that he could determine where the static was coming from. He began taking data in the summer of 1931. He correlated the static with weather reports, and determined that indeed, thunderstorm static could pose a problem. 

But Jansky didn’t stop there.  He noticed a tiny, yet persistent signal in his data.  He could’ve ignored it, but he didn’t....

August 1931 Work Report: "Static was strongest just before, during or after an electrical storm; however, nearly every night static was received from a source that apparently follows the same path….The reason for this phenomenon is not yet known…"

By autumn the "noise" had shifted from night-time to day. 

"Jan 32 work report: very steady continuous interference…that changes direction…going around the compass in 24 hours."

By December, 1932, Jansky recognized that the drift in the signal’s arrival was synchronized with the stars.   In a letter home, he wrote: "The stuff, whatever it is, comes from something not only extraterrestrial, but from outside the solar system. It comes from a direction fixed in space."

In 1933, he published his results and the science of radio astronomy was born.

To learn more about radio astronomy’s beginnings, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["03"] = "

Radio waves - How do you make them? Just two simple ingredients are required: charged particles like electrons, and a way to accelerate them. Your favorite radio station makes use of this simple recipe. If you listen to, say, 88.5 FM, your station is transmitting radio waves to you at a frequency of 88.5 megahertz. To produce this signal, the radio station accelerates electrons up and down a wire 88.5 million times a second!

If you could tune higher, say to 300 MHz and above, you’d enter the realm of radio astronomy.  In the universe, electrons are accelerated in three ways.

One process occurs in hot gas..  In star-forming clouds, new stars heat the surrounding gas to 10,000 degrees. Temperatures are hot enough that electrons and protons are free to zip around. As they accelerate, they emit waves across the spectrum, from visible light to radio waves.  The Great Orion Nebula is a spectacular example of such a star forming cloud.

A second process calls for magnetic fields. When fast moving electrons encounter magnetic fields, they spiral around the magnetic field lines.  This acceleration causes radio waves to be emitted. Regions around exploded stars, and black holes at the cores of distant galaxies emit radio waves in this way.

Molecules can also produce radio waves. In dense cold, dusty regions in galaxies, molecules form. These molecules emit signals at very specific frequencies as they vibrate and spin. Some of the molecules discovered by radio astronomers can be found right in your kitchen: ingredients in your favorite salad dressing, a box of cookies, and a bottle of beer can all be detected in deep space.

To learn more about the radio universe, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["04"] = "

In 1895, H.G. Wells published his first novel: The Time Machine.  In it, he envisioned the ability to travel through time at will.  The Time Machine is, of course, a work of Science Fiction… or is it?

Because distances between celestial objects are so great, astronomers use the light year as their yardstick. A light year is the distance light travels in one year. Visible light, radio waves, in fact, all forms of electromagnetic energy travel at a constant speed of 300,000 kilometers per second.  To calculate a light year, multiply 300,000 kilometers per second by 60 seconds in a minute, again by 60 minutes in an hour, then by 24 hours in a day, and finally, by 365 days in a year. The answer: …one light year is equal to just under nine and a half trillion kilometers.  That’s about 6 trillion miles! 

At cosmic distances, the light year is also, in a sense, a measure of time.  As we observe distant objects, we see them as they were, in the past. For example, the nearest bright star to earth is called Sirius is about 8.6 light years away. When you admire Sirius on some cold winter’s night, that starlight in your eyes left on its journey 8.6 years earlier!

Oh, but that’s nothing.  Radio astronomers have peered back to the fringes of the observable universe detecting distant galaxies 10 billion light years away.  And that means… that we glimpse these celestial objects as they were…10 billion years ago.  Although we can’t visit the future, present day astronomers do, in a sense, travel to the distant past to study the early universe. HG Wells would be proud.

To learn more about the distant and ancient universe, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["05"] = "

What if you could see radio waves instead of visible light? What would the sky look like?  First of all the whole sky would glow faintly, day and night.  The Milky Way would pave a glowing swath across the sky, and you would see thousands of small bright points of energy. 

Well, that sounds pretty familiar… but it really isn’t!

The faint glow filling the sky is radiation left behind from the Big Bang.  The Milky Way glows not from accumulated star light, but because of high speed electrons spiraling in magnetic fields. And all those bright points of light… they’re not familiar near-by stars, but galaxies and quasars billions of light years away. Galaxies and quasars made bright by supermassive black holes lurking in their cores.

Most large galaxies are thought to have black holes at their centers—objects so massive that nothing can escape their gravitational pull—not even light. But as material is pulled into a black hole it forms a spinning disk. Swirling  magnetic fields in these disks cause jets of plasma to stream away at supersonic speeds. These jets emit radio waves.

Our home galaxy, the Milky Way, contains a medium sized black hole that weighs as much as about 4 million suns.  But those in radio galaxies and quasars are hundreds of times more massive.

The physical processes near black holes at the cores of some quasars are capable of propelling matter very close to the absolute cosmic speed limit—the speed of light. Accelerating just one bowling ball to these speeds would require all the energy produced in the world for an entire week.

Welcome… to the radio universe.

To learn more about black holes, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["06"] = "

It didn’t take long after World War II for the new science of radio astronomy to burst onto the scene. After demonstrating what could be done with cast-off radar equipment, scientists and engineers began to design dedicated radio telescopes. They built ever larger instruments beginning in the 1950s in England. In the 1960s and 70s, radio telescopes sprouted up all over the world.

Now, there’s a new kid on the block, and it’s a BIG baby.

The Observatory’s new instrument, the Robert C. Byrd Green Bank Telescope, or GBT, is 485 feet tall, weighs 17 million pounds and supports a reflector that is two and a third acres in area!  You could easily fit a football field in the dish with plenty of room left over for the bleachers!

Just like a bigger bucket collects more raindrops, the Green Bank Telescope collects more radio waves than any other movable antenna out there. And that means astronomers can detect new cosmic processes that were previously too dim to see. Recent discoveries include a neutron star spinning 716 times/second, giant bubbles of gas rising out of our Milky Way; and molecules in galaxies 10 billion light years away.

The gigantic steel structure of the GBT provides a striking contrast to the idyllic rural West Virginia valley that surrounds it.   But you couldn’t ask for a better home. The mountainous countryside shields the GBT from manmade radio signals produced by, for example, airport radars, cell phone towers, and even radio stations located in more populous areas.

Want to visit the Green Bank Telescope?  Free Tours are available year round. To learn more, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["07"] = "

Although Galileo didn’t invent the telescope, he wasted no time building one for himself.  In the year 1610, he turned his simple spyglass toward the sun and was astounded to see numerous dark spots marring its surface. What were they? Were they tiny objects orbiting the sun or part of the sun itself? As Galileo traced the images over time, he noticed that the spots were all moving in the same direction. He deduced that the spots must be part of the sun, and that the sun itself was rotating. He was right.

We now know that sunspots are caused by the Sun's magnetic field tangling, twisting and then protruding through the Sun's visible surface, the photosphere. These powerful magnetic fields disturb the photosphere, and produce solar prominences and flares. They also produce radio waves.  Radio images of the Sun, made with the Very Large Array Telescope in New Mexico, show bright spots of emission in the solar atmosphere, directly above sunspots. There, the solar plasma extends into the corona and can reach temperatures of millions of degrees.

Occasionally solar explosions spew this plasma out toward Earth.  When these energetic particles hit the Earth’s magnetic field, they create the beautiful northern lights, but they can also fry satellite electronics and cause power blackouts. Even when the sun is calm, it produces a gentle wind of hot gas which streams past the earth into outer space. In a sense, because of the solar wind, the Earth is... inside the sun.

That’s why, today, telescopes on the ground and in space, study the sun and its interaction with Earth, continuing what Galileo started nearly 400 years ago.

To learn more about the radio sun, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["08"] = "

Cassiopeia, the Queen, is one of a few constellations visible all year long. That’s because it's located near the North star. Look for Cassiopeia circling the North Star  and you'll see a group of 5 bright stars in the shape of a W. 

One thing you won’t see is Cassiopeia A, a supernova remnant which, though invisible to your eyes, is one of the brightest radio sources in the sky.

About once every century in our galaxy, a massive star explodes in an event we call a supernova.  The material blasted outward by the supernova creates a bubble of super hot gas we call a supernova remnant. Cassiopeia A is the remnant of a supernova explosion that occurred over 300 years ago. Astronomers deduce this by measuring tiny outward motions in the gas over a period of years. Then they “rewind” the expansion to estimate the explosion date.

Taking the technique forward, scientists believe this hot shell of gas will continue to expand and produce radio waves for thousands of years. In fact, the material from the explosion is still moving outward at speeds exceeding ten million miles an hour!

A supernova occurs when a massive star has used up its nuclear fuel and can no longer hold itself up. Gravity drags the stellar material toward the star’s core heating it up to billions of degrees. This reverses the collapse into a violent rebound, propelling material into space. A supernova may briefly out-shine its entire host galaxy before fading from view. However, the supernova in Cassiopeia was not noticed by astronomers of the time, but only hundreds of years later when radio telescopes peered in the Queen’s direction.

To learn more about supernova remnants, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["09"] = "

We live in the suburbs of the Milky Way Galaxy, a flat, spiral-shaped galaxy resembling a cosmic pinwheel. Our solar system is just a small dot on one of the galaxy’s spiraling arms.

But from the Earth, the Milky Way just looks like a faint hazy band of light stretching across the sky.  It looks like this because our view is from inside the Milky Way. 

So, even though the Milky Way is our home, in many ways it’s harder for us to see and study than other, more distant galaxies. It’s like trying to determine what your house looks like from the inside, without stepping outdoors!

Optical telescopes help, but their visibility is limited by dust in the Galaxy’s spiral arms. Visible light is blocked by these dust particles. Radio waves, on the other hand, travel right on through, allowing scientists to peer deep into the Milky Way’s structure.

Astronomers map the galaxy’s structure using radio signals produced by the simplest element of them all: hydrogen. When hydrogen atoms flip from a higher energy state to a slightly lower one, they release this excess energy as radio waves.  Since there are countless hydrogen atoms in the galaxy, the signal is loud and clear.

Radio data show that the hydrogen gas is not smoothly distributed throughout the galaxy, but organized into discreet clumps or bands-- spiral arms in other words. These clouds are in motion, circling at different rates depending on their distance from the center. Out in the suburbs, our solar system orbits the galaxy’s center at 130 miles per second! Even at that speed, it takes us 250 million years to complete each journey.

To learn more about the Milky Way, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["10"] = "

Halfway between the constellations of Cassiopeia the Queen and the Great Square of Pegasus, lies the … the Andromeda Galaxy ; the only object outside our own Milky Way  we can see with the naked eye. This giant pinwheel in the constellation of Andromeda is about two and a half million light years away; the nearest major galaxy to our own. 

If we could look back at the Milky Way from afar, it would probably look something like Andromeda. Both galaxies are giant spirals, containing gas, dust, and hundreds of billions of stars like the Sun.

Scientists wonder how these huge spiral galaxies formed. One idea is that they are built out of smaller galaxies and bits of gas in a gradual process lasting billions of years. Astronomers using the Green Bank Telescope in West Virginia, may have discovered scrap left over from this period of galactic growth… primitive gas clouds in orbit around Andromeda.

The gas clouds surrounding the Andromeda galaxy don’t give off light, but they do give off very weak radio waves. They’re hard to see in the bright radio glare of the galaxy itself. It’s like trying to see the flame from a candle placed next to a spotlight. The Green Bank Telescope’s large size was key to enabling astronomers to discover about 20 discrete hydrogen clouds hovering around Andromeda.

Each of the gas clouds contains enough matter to form a million stars like the sun. They are gravitationally bound to the galaxy, and so appear to be the surplus building materials at the construction site of the Andromeda Galaxy.

To learn more about spiral galaxies, visit the National Radio Astronomy Observatory web site at www.nrao.edu.

"; fullScripts["11"] = "

Radio. Images. Radio images? Sounds like an oxymoron, doesn’t it? But radio telescopes often produce images of celestial bodies. Just as photographic film records the light coming from different parts of a scene, radio telescopes record the radio emission coming from different parts of the sky. After processing this information, astronomers can make a picture.

Of course, the devil’s in the details. Because radio waves are so much longer in wavelength than visible light, a radio telescope would need to be 20 miles across to make an image that’s as detailed as one made with the Hubble Space Telescope.

And that’s impossible. So how do radio astronomers produce images that rival optical photographs in detail?

By linking small telescopes together to simulate a large one.  Here’s how it works:  Take two small radio telescopes, place them 20 miles apart and point them at the same object. Carefully combine the signals each dish receives and you can resolve details as well as one single telescope that’s 20 miles across. 

There’s only one problem. Radio waves are captured only at the two small dishes, not in between. So, although a pair of linked telescopes has better resolution, it isn’t very sensitive. The fix: add more dishes.

In the 1970s, the National Science Foundation set out to do just that. The result is the Very Large Array, 27 radio dishes spread across the Plains of San Agustin in western New Mexico.  The antennas can be positioned to simulate a single telescope over 22 miles in diameter.  By combining the signals from all the antennas astronomers get a sensitive telescope with resolution akin to being able to see a golf ball 100 miles away!

To learn more about the Very Large Array, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["12"] = "

Interstellar travelers might want to detour around the star system TW Hydrae to avoid a messy planetary construction site. Astronomer David Wilner and his colleagues have discovered that the gaseous disk surrounding this star contains vast swaths of pebbles extending outward for at least 1 billion miles. These rocky chunks could continue to grow in size until they eventually form planets.

Wilner used the Very Large Array telescope in New Mexico to measure radio emission from TW Hydrae. He detected radiation from a cold, extended dust disk full of centimeter-sized pebbles. Such pebbles are an early  stage in planet formation, as dust collects together into larger and larger clumps. Over millions of years, those clumps may grow into planets. No one has seen this stage in planet formation before.

A dusty disk like that around TW Hydrae tends to emit radio waves with wavelengths similar in size to the particles in the disk. The scientists detected strong signals at wavelengths of a few centimeters indicating that pebbles of that size are present. They estimate the disk surrounding the star contains plenty of planet building material, more than enough to form one or more Jupiter-sized planets.

The star TW Hydrae is special. It's nearby, only 180 light-years away, and that means easy to study.  It’s about 10 million years old-- just the right age to begin forming planets. And it’s only slightly smaller than our own star, the sun. That makes this system the closest analog to our solar system, when it was under construction.

David Wilner is a scientist at the Harvard-Smithsonian Center for Astrophysics.

To learn more about our universe, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["13"] = "

"Behold Orion rise!
His arms extended stretch over half the skies.
His stride as large and with steady pace
He marches on and measures a vast space.
On each shoulder a bright star displayed
And three obliquely grace his hanging blade."

As this ancient Roman poem implies, Orion the Hunter is an easy winter constellation to find. Three bright stars in a diagonal line mark Orion's belt. And suspended just beneath his belt you’ll see three fainter stars that make up his sword. The middle star’s not really a star at all but a glowing cloud of gas, called the Great Orion Nebula. With a pair of binoculars you can see this for yourself.

The entire Orion constellation is of interest to radio astronomers, but not because of its bright stars. Imaged through a radio telescope, this region of the sky reveals a giant molecular cloud, where new stars are born.

The Orion Molecular Cloud is a vast dark cloud of matter that invisibly occupies much of the constellation. The cloud, which is about 1,300 light years from Earth, is dense and dusty, preventing optical telescopes from seeing inside. 

As the name suggests, molecular clouds contain molecules-- molecules which emit radio waves. Since radio waves pass through dust and gas, these clouds, and the molecules within them, can be studied with radio telescopes.  As they slowly collapse under the force of gravity, radio astronomers catch a glimpse of star formation in action.

Eventually some portions of the dark cloud will become visible, as ultraviolet  rays from hot newborn stars excite the gassy cocoons around them. That makes them glow.  Such is the case with the Great Orion Nebula, in Orion’s sword.

To learn more about Orion, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["14"] = "

Most scientists agree that the universe began some 14 billion years ago in an explosive event known as the Big Bang. The "Big Bang" is a scientific theory about the origin and evolution of the universe. A scientific theory is more than "just a theory".  Scientific theories are based on evidence, and  predict new phenomena. So what is the evidence for the Big Bang?

First, in the 1930s, Edwin Hubble noticed that almost every galaxy he observed seemed to be moving away from us. Even stranger, galaxies at greater and greater distances were moving away faster and faster. This implies that they all started from a single place, and at the same time.

The most convincing evidence of all, though, came about through a spectacular coincidence.   In 1960, scientists at Princeton University were developing ways to test the Big Bang theory. They reasoned that, if the universe began in a cataclysmic explosion, there should be some telltale residue of light left over.  And secondly, the ensuing expansion of the universe would cause that light to be … stretched… into radio waves.

Meanwhile, two young astronomers at Bell Laboratories were puzzling over a tiny radio signal they had detected, and could not explain. Arno Penzias and Bob Wilson found these radio waves coming from every direction in the sky.

You can guess the rest.  Their discovery matched the Princeton prediction perfectly. What they saw is called the Cosmic Background Radiation, a cosmic whisper filling the universe left behind by the Big Bang. They received the Nobel Prize for their work in 1978.

To learn more about the Big Bang, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["15"] = "

How do we know that the Sun’s temperature is about 6,000 degrees? You can’t just stick a thermometer in it!  We know because it’s yellow. In fact every time you notice the color of a star you have taken the temperature of that distant, massive ball of gas! This is possible through the power of blackbody radiation.

Hot, dense things like a stove-top burner, the filament in a light bulb, or a star are called blackbodies. They glow when they’re heated. Their color depends only on their temperature.

Every blackbody emits light with an easily identified pattern called a blackbody curve. All blackbody curves have the same shape, but where the curve peaks is different. Cool red stars peak at a longer wavelength--- in the red part of the spectrum as a matter of fact. Hot blue stars peak at shorter wavelengths-- in the blue or ultraviolet part of the spectrum.  Really, really hot objects, like exploding stars may have blackbody curves which peak in very high-frequency x-rays, indicating temperatures of 1 million degrees or more!

You are a black body radiator too! But you’re not hot enough to emit visible light (thank goodness)!  Since your temperature is only about 100 degrees Fahrenheit, the peak of your blackbody curve is in the infrared. 

In fact, the whole universe has a black body curve which peaks in the radio part of the spectrum, indicating a temperature close to absolute zero. That’s 454 degrees below zero Fahrenheit. This black body radiation comes from the dawn of our observable universe, the Big Bang itself. Since then the universe has expanded and cooled. The discovery of this blackbody radiation changed our view of the universe forever.

To learn more about blackbodies, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["16"] = "

When astronomer Frank Drake was eight years old, he wondered if humankind was the only intelligent life in the Universe.   Twenty-one years later, when he came to work at the National Radio Astronomy Observatory in Green Bank, West Virginia, he thought he just might have the tools to find out.  He devised an experiment and whimsically called it Project Ozma, in reference to a princess in the land of Oz.

Drake selected two nearby sun-like stars to observe. His plan was to track first one star and then the other, searching for a pattern in the signals that would indicate an intelligent message.

So, on the morning of April 8th, 1960 he steered the observatory’s 85-Foot diameter radio telescope toward the star Tau Ceti to begin the search for extra-terrestrial intelligence. ... Nothing. No signal at all.  When Tau Ceti set at noon, Drake pointed the telescope toward Epsilon Eridani. Suddenly, the needle on the chart recorder began to jump. Bursts of noise boomed from loudspeakers. Could it be that easy to detect life in outer space? Drake pointed the telescope away from the star, and then back on, to be sure of the signal. But the signal was gone.

In fact, he didn’t see that particular signal again until 10 days later, when further tests showed that it was only a transmitter from a passing airplane.

After 4 months, Project Ozma came to an end. Although Frank Drake hadn’t heard any signals, he turned the search for civilizations on other worlds into a feasible scientific endeavor.

To learn more about the Search for Extra Terrestrial Intelligence, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["17"] = "

Are we alone?  Do other forms of life exist in the Milky Way? If so, is that life intelligent?  And, if so, are they …nice?  We humans have been fascinated by these questions for centuries. Sometimes, our collective imagination can run a little wild, as happened when Orson Wells broadcast news of a Martian Invasion on the radio in 1938.  He was just kidding, but widespread panic ensued, as people streamed out of their homes to scan the skies for signs of Martian spacecraft.

In reality astronomers use telescopes to search for signs of life in our galaxy. Some search for deliberate communication signals from intelligent civilizations. Others hunt for planets around distant stars. And still others look for the molecular origins of life: compounds that form the backbone structure of DNA, the genetic code present in all forms of life.

Recently, astronomers using the Green Bank Telescope in West Virginia detected the simple sugar, glycoaldehyde, by precisely measuring the faint radio emission from the molecules.

Glycolaldehyde was found in an interstellar cloud near the centerof our galaxy. Two facts make this discovery exciting: Glycoaldehyde reacts with other molecules to form ribose, an essential constituent of DNA.  Secondly, the molecules were detected in a cold interstellar cloud, long before stars and solar systems begin to form within it.  These molecules may survive the formation of a new solar system, lingering in the cold outer regions where comets reside.  Later encounters with comets could conceivably "seed" a young planet with the molecular building blocks of… life.

To learn more about the molecular origins of life, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["18"] = "

Imagine building a radio telescope as large as the earth itself.  That’s exactly what the National Radio Astronomy Observatory has done.  The telescope is called the Very Long Baseline Array, or VLBA. Radio telescopes look like large satellite dishes, but, obviously, the VLBA’s not one gigantic dish. As the name implies, it’s an array of ten dishes that work together.  Scattered across the United States, the antennas simulate a single dish 5,000 miles in diameter!  The level of cosmic detail revealed by the VLBA is like being able to stand in New York and read a newspaper in LA!

Because the dishes are spread so far apart, each telescope site records the astronomical data separately, on tape. Once the tapes are shipped to the Array Operations Center in Socorro, New Mexico, they are synched up using atomic clock signals, replayed and multiplied together.  The resulting data, analyzed by astronomers from around the world, is used to make detailed images of the most distant objects in the universe.

While the Very Long Baseline Array is run by remote control in Socorro, the dishes themselves are tucked away in remote rural locations where there’s little radio frequency interference from man-made sources.

There may be a VLBA dish near you! You can find them stretching from Saint Croix in the Virgin Islands, across the continental United States, all the way to the Mauna Kea volcano on the big island of Hawaii. If you visit, you’ll see a single dish that looks impressively large in its own right, but remember, it’s only one small part of a telescope that’s 5,000 miles across!

To learn more about the Very Long Baseline Array, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["19"] = "

You just bought your first telescope and can’t wait to start observing the heavens. But where do you set it up?  Unless you live out in the country, chances are the glare from street lights will make it impossible to see the stars. We call this glare from man-made lights, light pollution.

Optical astronomers need dark skies for their optical telescopes, but radio astronomers need, well … quiet skies. While light pollution makes it harder to see the stars at night, radio pollution makes it harder to detect cosmic radio signals. To a radio telescope, a typical one-watt cell phone located on the moon would be the strongest radio source in the sky!

That’s why the Federal Communications Commission created the National Radio Quiet Zone, a 13,000 square-mile preserve for radio astronomy around the radio observatory in Green Bank, WV. Just as a nature preserve protects wildlife, the Quiet Zone protects the largest moveable telescope on earth from radio pollution caused by transmitters, like, well for instance ...cell telephone towers. In fact, if you visit the Observatory in Green Bank, you’ll soon find your cell-phone doesn’t work there!

Although the Quiet Zone regulates commercial transmitters, that doesn’t mean skies over Green Bank are completely silent.  A prime threat comes from transmitters in Earth-orbiting satellites.  Those transmitters are located overhead, precisely where radio astronomers aim their telescopes. And the proliferation of wireless networks, microwave ovens, and even remote controlled toys has raised the level of radio pollution in this remote hamlet, effectively blinding the telescopes at certain frequencies.

So, next time you’re looking for a nice dark location for stargazing, remember--astronomers need quiet skies as well.

To learn more about radio pollution, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["20"] = "

Two days after Christmas in 2004, spacecraft designed to detect super high energy gamma-rays detected a giant flash of energy from thousands of light-years away – the biggest, brightest explosion astronomers had ever seen from outside of our Solar System. The flash blasted the Earth's ionosphere, causing a sudden disruption in radio communications. Although the initial gamma ray burst faded away in just minutes, the explosion's radio "afterglow" was tracked by the Very Large Array radio telescope for weeks.

The explosion came from a neutron star.

Neutron stars are stellar corpses, left behind when massive stars implode at the end of their lives.  Thousands of neutron stars have been discovered and studied. But this one is different.

This neutron star is called a magnetar. Its magnetic field is thousands of trillions of times stronger than Earth’s. Scientists believe the giant burst of energy was somehow triggered by a "starquake" in the magnetar's crust. The starquake disrupted the magnetic field, causing a huge release of gamma rays and radio waves. All-told, it would take our Sun more than a million years to radiate the energy released by this magnetar in just two tenths of a second.

Although there are only a dozen or so magnetars known to astronomers, and only two where such giant outbursts have been seen, perhaps they are more common than we think.

For years, enigmatic gamma-ray bursts have been seen all over the sky, and nobody’s sure what causes them. But a flash this bright could be detected even at even the most distant reaches of the universe. Maybe they’re... "starquaking" magnetars in far-flung galaxies.

To learn more about magnetars, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["21"] = "

In between Karl Jansky’s discovery of cosmic radio waves in 1932 and the end of the second World War, one man, working alone, advanced the science of Radio Astronomy.

That man was Grote Reber.

Grote Reber was an accomplished Amateur Radio Operator--or Ham--when news of Jansky’s discovery reached him. He had built his own short wave radios and communicated with fellow amateurs on all 6 continents of the world.  By the age of 26, he felt "there were no new worlds to conquer" in his hobby.

So, it’s not surprising Reber was enchanted by Jansky’s discovery and imagined putting his hobby to an exciting new use. Beginning in 1937, he built the world’s first radio telescope in his own backyard.

Reber’s telescope was a parabolic dish capable of focusing radio waves at many wavelengths. Jansky had discovered cosmic radio signals at a wavelength of 14 meters. Because of the way stars radiate, Reber reasoned that these signals would be even stronger at shorter wavelengths. So, he built a receiver that operated at 9 centimeters wavelength.

He detected nothing.

He built a second receiver that operated at 33 centimeters wavelength.  Again, the results were negative.

Undaunted, he constructed a third receiver, this time for a wavelength of 1.9 meters.

In 1939, Reber was at last successful in detecting cosmic radio waves.  He made a complete survey, and published the first maps of the radio sky in 1943.

After World War II, radio astronomy became a legitimate science, thanks in large part to Grote Reber, lone pioneer.

To learn more about Grote Reber, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["22"] = "

In 1969, Neil Armstrong made history when he stepped from the lunar module onto the moon itself.  If we humans ever go back, it may be to stay awhile, in temporary lunar colonies.  One of our biggest hurdles will be supplying ourselves with the basics needed for survival: air to breathe, food to eat…and water.  Wouldn’t it be nice, if buried beneath the moon’s surface, there was a ready made source of water?

Impossible you say!  Every month the entire moon is exposed to the sun.  There is no atmosphere on the moon, so any water would quickly evaporate. 

Those are excellent arguments, unless… there are places on the moon where the sun don’t shine... literally!

It turns out that deep craters near the moon’s poles might be such shady places, and Smithsonian astronomer Bruce Campbell and colleagues decided to take a look.  Armed with the knowledge that layers of ice are found in polar craters on planet Mercury, they used a similar technique to look on the moon… radar.

The team used the giant Arecibo Telescope in Puerto Rico to transmit a blast of radio waves at the polar regions of the moon. The reflected signals were detected by the Green Bank Telescope in West Virginia. Campbell’s team then processed the data to create high definition radar maps.

Thick layers of ice buried at the bottom of lunar craters would show up as bright spots on radar maps. Unfortunately the results don’t look promising for moon water; there are no bright radar reflections in Campbell’s maps. If water is present at all. it must be distributed as small grains or in thin layers, making it less useful to future lunar residents.  Oh well.  Aquafina will be pleased!

To learn more about ice on the moon, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["23"] = "

Stars are born, they live, and they die. Low mass stars go out with a whimper; massive stars go out with a bang… literally!

Adult stars negotiate an intricate balancing act.  On the one hand, gravity pulls all the stellar material toward the center of the star.  One the other, nuclear fusion generates heat and outward pressure that pushes the gas away from the center.  When these two opposing forces equal each other the star is stable. All is well for millions or billions of years until the star spends all of its fuel.  Then gravity takes over.  For massive stars the results are spectacular.  All remaining stellar gas races to the center and rebounds in a gargantuan explosion.

This explosion blows off the outer layers of the star into a beautiful supernova remnant. The central region of the star continues to collapse under gravity to form an incredibly dense object. This neutron star, as it’s called, has the mass of the sun, collapsed into a sphere the size of your nearest city!  On Earth, one teaspoonful would weigh as much as 20,000 cruise ships.

It gets stranger. Stars spin. Our sun makes a complete rotation once every 25 days. But, like a spinning figure skater pulling her arms in, neutron stars spin much more rapidly than their parent star. And they beam radio waves from their poles. So, if we're lucky and the star is oriented advantageously, we detect a neutron star by a radio blip—one for every rotation.  A cosmic lighthouse, so to speak.

We call these neutron stars pulsars. Introducing the Vela Pulsar, spinning 11 times per second...

Wow! You gotta love the universe!

To learn more about pulsars, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["24"] = "

Optical and radio astronomy share one important advantage. Both can be done from the ground. The Earth’s atmosphere is transparent to visible light, and to radio waves, enabling us to see through it to study the universe.  

But even visible light and some radio waves don’t pass through completely unscathed.  If you look up on some cloudless night, you’ll notice that the stars twinkle. While this atmospheric effect is charming in its way, it does prevent ground-based optical telescopes from seeing clearly.  The Hubble Space Telescope produces such spectacular images, in part, because it’s…well… in space.

Radio waves at the shortest of wavelengths are degraded by the atmosphere too. In this case, water vapor is the culprit; the tiny droplets scatter the waves in all directions before they reach the ground.

That’s why the Atacama Large Millimeter Array, or ALMA, is being built on the plains of a high Chilean desert, dubbed the driest place on Earth. The Atacama Desert at 16500 feet above sea level, contains sterile lifeless stretches where rain has never been recorded. And that makes it a perfect place for a new telescope capable of detecting radio waves just millimeters in wavelength.

The Atacama Desert is not a good place for humans, though. At that elevation, it’s not just dry-- oxygen is in short supply too.  When North American astronomers begin to use ALMA in 2012, they will do so from the North American ALMA Science Center in Charlottesville, Virginia. And when they do, they’ll make spectacular discoveries; unveiling never-before-seen regions such as infant stars in dust-shrouded nurseries, newly forming planets and even... the environs around supermassive blackholes.

To learn more about ALMA, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["25"] = "

The infant science of radio astronomy profited from the development of radar in World War II. Some of the earliest radio astronomy pioneers came from Britain and Australia  where research in radar was critical for survival during the war.  One of these pioneers was the first woman radio astronomer: Ruby Payne-Scott.

Born in Grafton, New South Wales, in 1912, Ruby Payne-Scott was the third woman ever to graduate with a degree in physics from Sydney University.  That in itself was an accomplishment for a woman in those days, but landing a job in physics was even more of a challenge.

When World War II began, 60 of Australia’s best physicists were recruited to develop radar and make it as accurate as possible. Payne-Scott was one of them. In 1941 she joined the Radio Physics division at the Australian Council for Scientific and Industrial Research.  Remarkably , after the war, Payne-Scott, retained her position as a physicist with the Council. She put left over radar equipment  to good use in the nascent field of radio astronomy, pioneering early radio studies of the sun.

In the 1940s, conventional wisdom held the temperature of the sun's surface to be 6000 degrees. Payne-Scott, and colleagues determined the temperature of the sun's corona to be over a million degrees, which optical astronomers found incredible at the time.

Because of discriminatory policies toward women, Ruby Payne-Scott was forced to hide her marriage in 1944 to avoid losing her position as a permanent employee in the Radio Physics division.  In 1950, pregnant with her first child, she admitted to the marriage and left the world of professional physics behind.

To learn more about radio astronomy pioneers, visit the National Radio Astronomy Observatory website at www.nrao.edu.

"; fullScripts["26"] = "

Jupiter, the largest planet in our solar system, looks like a bright star to the naked eye. But, through even a small telescope we can see that this "star" is a planet with features. We see stripes in Jupiter’s cloud tops and a gigantic swirling storm called the Great Red Spot. This storm is nearly three times larger than Earth.  That’s impressive.

Equally impressive, this planet is a giant radio transmitter.  Magnetic storms cause the radio emission.  Like Earth, Jupiter has a magnetic field that extends far above its cloud tops. But it’s much stronger. This magnetic field traps fast moving electrons, creating displays like our northern lights, and radio waves.

At low frequencies, Jupiter’s radio signals appear to be enhanced by its closest moon, Io.  As Io orbits the planet, it disturbs Jupiter’s magnetic field, increasing the number of low frequency radio bursts. With a short-wave radio coupled to a modest antenna, you can easily detect these signals yourself. Two types are common, long, or L bursts, that sound like waves crashing on a beach and short or S-bursts that sound like popcorn popping.

At higher frequencies, radio signals are produced by electrons spinning around Jupiter’s magnetic field at velocities close to the speed of light!  These zippy particles emit radio waves that trace large extended lobes beyond the planet itself.  In false color radio images, Jupiter looks more like a large flattened salamander, than the familiar striped disk seen through optical telescopes.

Thanks to Radio Jove for providing audio for this program. To learn more about Jupiter, visit the National Radio Astronomy Observatory website at www.nrao.edu.

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