National Geographic Explores Redwood Forest

The National Geographic Channel is presenting a new reality adventure series in the Redwood Forest, as two explorers venture on extreme journey among the world's tallest trees. Explorer: Climbing Redwood Giants debuts on Tuesday, September 29, 2009 at 10 PM ET. The story of the Redwoods is also being featured in the October issue of National Geographic, in “The Tallest Trees.

The Giant Redwoods

The stately Redwoods of Northern California and Oregon are a primeval forest that have been the subject of heated environmental battles for many years. When European settlers arrived in the western states in the the mid 1800s they starting cutting down the giant Redwoods. Today less than 5% of the ancient trees of the Redwood Forest remain. Conservationists continue to battle to preserve the ancient giants.

The new National Geographic series will take viewers along on an extreme adventure, to see the Redwoods from a unique viewpoint. The majesty of the Redwoods can be experienced from the images on the cable television series and in the October issue of the National Geographic Magazine.

Explorer: Climbing Redwood Giants

Explorers Mike Fay and Steve Sillet have each gone on extreme journeys in the Redwood Forest and their adventures have been documented on the National Geographic series.

Conservationist and National Geographic Explorer in Residence Mike Fay walked the entire Redwood Forest in 2007 – 2008. Fay set out to walk the entire range of Redwoods and study the effects of forestry management on the survival of the great trees. Sillet walked on foot through 1,800 miles of Redwood territory. Fay's journey took place over an 11 month period.

Forest Scientist Steve Sillet explored the tops of the Redwoods by climbing the giant trees. Sillet of Humboldt University, is the first scientist to climb up into the canopies of the Redwoods and study their rich ecosystems. Fay climbed the trees with over 350 feet of rope to study the hidden canopy ecosystems of the ancients Redwood Trees..The series will reveals findings that Sillet gathered over eight years of research on the Redwood Forest.

The stories of the explorations of the two men will be told in National Geographic Channel's Explorer: Climbing Redwood Giants. The series premieres on Tuesday, September 29, 2009 at 10 PM ET and will air in one hour episodes on Tuesday nights.

The Tallest Trees

The October issue is featuring the Redwoods as the cover story. The magazine also includes a pull out poster of a full length digital portrait of a stately Redwood Tree. The portrait is composed of 84 images which are stitched together.

The Redwood Forest is a National treasure. The National Geographic Channel series and magazine feature about the Redwoods should help viewers to appreciate the rare beauty of the giant Redwoods

Active Earth

Cool Planet

And what a long, long story it is. Earth is over 4.5 billion years old! When Earth first formed, it didn't have different layers. It didn't have oceans or mountains, either. In fact, you might not have recognized our cool, blue planet. It was just a big, sizzling blob of melted rock.

Slowly, Earth cooled. As it cooled, the heaviest materials, such as iron, sank down. Lighter materials, such as the mineral silica, rose to the surface. Over hundreds of millions of years, the materials settled into three layers.

No one has drilled to Earth's deepest layers yet. Even so, geologists have an idea of what those layers are like from studying seismic waves. Those are waves of energy caused by earthquakes. As they travel through Earth, the waves move quickly through some layers and more slowly through others. Geologists know some layers are made of liquid metal, such as iron. They know others are solid rock.

Core to Crust

To picture Earth's layers, think of a hard-boiled egg. Picture the yolk, the egg white, and the eggshell. Earth's "yolk" is called the core. It's thousands of miles below your feet—and it's hotter than hot! Temperatures in the core can reach over 6,650°C (12,000°F). The core is made of metals—mostly iron and nickel.

Above the core, like an egg white, is Earth's thick mantle. The mantle is made of partially melted rock. Finally, above the mantle is Earth's cool crust—the eggshell.

The crust is our home sweet home. All you can see is part of it—canyons, fields, even oceans. The crust varies in thickness from 5 to 100 kilometers (3 to 62 miles). That may sound thick, but compared to Earth's other layers, the crust is thinner than that eggshell.

Giant Jigsaw

The crust may seem rock-solid to you. In fact, it's cracked! Like a jigsaw puzzle, the crust is broken into huge pieces, called tectonic plates. These plates don't stay put. They are always on the move. At first, scientists weren't sure what pushed the plates around. They now believe the answer comes from Earth's core.

The core is like a hot burner. It heats the mantle above. Rock in the mantle gets lighter as it heats up. That causes the partially melted rock to rise. As it moves farther from the core's heat, the rock cools down and then sinks again. This constant rising and sinking makes a slow, circular current.

The plates float on top of it all. The currents push and pull at the plates from below, causing them to move. As the plates shift, they take the continents along for a bumpy ride!

Slow Going

The plates don't exactly zoom along quickly. The fastest-moving plate only moves about 15 centimeters (6 inches) per year. Yet over time, those inches start to add up. Inch by inch, continents are pulled apart and oceans are split.

About 225 million years ago, all the continents were nestled together in a mass called Pangaea. As the plates moved, they slowly pulled the continents apart. Look closely at the east coast of South America and the west coast of Africa. You'll see that it's almost a perfect fit!

That's no coincidence. These continents were once joined. At one point in time, Antarctica was in the tropics. And Australia was in the Antarctic! Talk about topsy-turvy. In 100 million years, Earth's map will look quite different than it does today.

Collision!

As the plates move, they crash into each other like bumper cars. We see and feel the shifting in many ways: earthquakes, volcanoes, mountain ranges—even hot springs!

Most of this action happens at the edges of the plates, where they meet. Plates can meet at convergent, divergent, or transform boundaries. A convergent boundary is where two plates collide. A collision between two continents is a real head-banger. It causes the plates to push upward.

That's what's been happening as India crunches into the Asian plate. The plate carrying Asia has been pushed up. Way up. In fact, the collision has created the towering Himalaya mountains! This huge collision is still going on. As it does, the Himalaya grow taller.

Something different happens when an ocean plate collides with a continental plate. Instead of rising up, the heavier ocean plate takes a dive. The deeper into Earth, the hotter it gets.

Pull and Push

The second type of boundary is called a divergent boundary. That's where two plates move apart. As they split, deep rift valleys form. Volcanoes sizzle as magma, or molten rock, oozes into the gap.

The East African Rift Zone, for example, is filled with volcanoes. Iceland straddles two plates, too. In places, you can peer right into the gap between the plates.

The third type of boundary is a transform fault. That's where two plates slide past each other. This is happening in California. There, the land is split by a deep fracture called the San Andreas Fault.

On the west side of this fault, the Pacific plate creeps north. Earthquakes rattle and shake California as the Pacific plate jerks and grinds along. Guess what's riding on top of it. The city of Los Angeles! In about 29 million years, Los Angeles will slide right past San Francisco.

Ring of Fire

If you really want to catch some plate boundary action, head for the Ring of Fire. That's what geologists call the edges of the Pacific plate. The Ring of Fire is definitely action-packed. In fact, it is home to 75 percent of Earth's active land volcanoes and about 80 percent of the planet's earthquakes.

To see the Ring, check out a map of the Pacific Ocean. Volcanoes cluster all around it! To the north, volcanoes dot Alaska's Aleutian Islands. In the west, Japan and Indonesia shake, rattle, and roll with strong earthquakes and fiery, hot volcanoes.

Closer to home on the Pacific's eastern edge, volcanoes poke out of the Cascade Arc. The Arc covers areas of northern California, Oregon, Washington, and parts of Canada. Here, you can find towering volcanic giants such as Mount St. Helens and Mount Rainier.

Into the Mantle?

We know that Earth's hot, active interior shapes our rocky home on the surface. But deep down, Earth still holds many secrets. Scientists, like those aboard The JR, have barely scratched the surface. They aren't trying to drill to the core, or even the mantle.

Not yet, at least. For now, they just want to reach deep into the crust. By the fall of 2009, they had drilled over a mile into the crust. It'll probably be another 10 to 20 years before scientists reach the mantle. But when they do, it will be a quite a thrilling moment. What will real mantle rock look like? What new things will it reveal about Earth?

There are so many more questions left to answer. Yet until scientists actually reach the mantle, they'll keep asking questions and wondering what's really going on deep down in our planet.

Turtle Travels

Out From the Sand
It's a starry night in August. A clutch of eggs lies hidden more than two feet below a sandy beach. The nest holds more than 100 eggs. Each egg is about the size of a golf ball. Inside each one, there may be a baby green sea turtle.

From the start, what happens to these turtles depends on the environment. The temperature of the sand determines whether sea turtles hatch as male or female. The sand here on Costa Rica's Tortuguero Beach is warm. So more of the hatchlings will be female.

One of the turtles begins to stir inside her shell. She tears at it with her caruncle. That's a sharp point on her beak. Still buried beneath the sand, she breaks free from her shell. Soon, the whole nest is alive with motion.

The baby turtle uses her flippers to climb up and up. It can take more than a day to reach the surface. She moves around, even stepping on top of her nest mates. Their movements help push sand toward the bottom of the nest. This gives the tiny turtles a boost to the top. All at once, the turtles free themselves from the sand.

From the Sand to Sea

The hatchling leaves the nest with many other baby turtles. She heads downhill, toward the horizon. That's where the sky and sea meet. She's drawn to the moonlight reflecting off the ocean. Luckily, there are no lights shining from a nearby street or house. These lights can confuse a baby turtle. They can make it to go the wrong way, away from the sea.

The hatchling's journey to the water is a race for survival. She is no bigger than a walnut. Crabs and night herons snatch up some of the other hatchlings on the beach. This young turtle makes it to the water.

The frothy surf pushes her back. She fights to swim against the breaking waves. Over and over, she dives under the waves, then comes up for air. Her swim continues through the first day and night. The young turtle will not slow down for two days.

To the Open Ocean

Scientists know little about the next phase of a green sea turtle's life. This period is often called the "lost years." A couple days after leaving her nest, the little turtle may reach the open sea. The turtle's journey through the open ocean may last several years. She may move with the currents. Scientists think green sea turtle hatchlings float with mats of sargassum. This seaweed provides a hiding place as well as food.

The hatchling may snack on shrimp, small jellyfish and snails that drift in and around the seaweed. Unfortunately, the sea also contains plastic and trash that people throw away. Eating them could be a deadly mistake for the turtle.

There are many other dangers in the sea, too. Predators such as sharks swim below the small turtle. Large birds fly above. They might decide to make a meal of her.

The turtle gets some protection from the coloring of her shell. The bottom is almost white. Sharks swimming below may not spot her pale shell. It blends into the sunlit water. The top of her shell, or carapace, is dark. From above, the turtle blends into the dark water.

After several years pass, she is a juvenile. Her shell is about the size of a dinner plate. Soon it is time to leave the open ocean for coastal waters.

Growing Up Green

The sea turtle's new home is the warm waters along Floride's east coast. With her larger shell, she is safer in the near-shore waters than she was as a hatchling. Though she sometimes slurps up a jellyfish, she now eats mostly algae and sea grass.

The sea turtle slowly grows larger. Soon she moves to feeding grounds farther off shore where she grows into an adult. There, she eats a sea grass called turtle grass.

At night, the turtle rests in the water under rocks and ledges. She can hold her breath for up to five hours! Each day, she returns to graze on her plot of grass. She uses her sharp beak to tear and eat the young shoots.

Like a lawn mower, the turtle keeps the sea grass pastures cut short. This helps new grasses grow and keeps the pastures healthy. Eating sea grass and algae has turned her body fat a green color. In fact, this is how green sea turtles get their name!

Return to Tortuguero

When the turtle is about 26 years old, her shell is a meter (3.2 feet) long. She weighs around 136 kilograms (300 pounds). Now the adult turtle sets out on a new adventure.

She must return to the beach where she was born to lay her eggs. She begins her long trek back to Tortuguero. She may have to travel over 1,000 kilometers (621 miles) to get there.

Scientists are still learning how sea turtles find their way through the ocean. They think the turtles may sense changes in Earth's magnetic field. That may help the turtles create a kind of mental map. Their memory of chemicals or odors in the water also may help them find their way.

The turtle is well equipped for the journey. Her flippers are like wings. She flies through the water. Using her senses and strong flippers, she finds her way to Tortuguero. There, she finds a mate. A few weeks later, she climbs onto the beach. It is after dark when she arrives.

The Next Generation

Out of the water, she struggles to move on land. She lumbers over the sand. She reaches a place where high tides will not wash away her eggs. Then she starts to dig.

She uses her front flippers to toss up sand. She shifts from side to side until she has a pit wider than her body. She uses her rear flippers to scoop out a smaller hole inside the pit. After two hours of hard work, she is ready to lay her eggs inside the smaller, deeper hole.

Her eggs fall into the deeper chamber, up to four at a time. She lays more than 100 leathery white eggs. She packs sand over them. Then she uses her flippers to toss sand to cover her nest.

In two weeks, the turtle will lay another clutch of eggs, and two weeks later, another. After about two months in the nests, new green sea turtles will hatch. They will begin their own journeys.

Saving Sea Turtles

This sea turtle and her hatchlings face many threats. Not all of them are natural. People hunt and eat sea turtles and their eggs. Many sea turtles are injured by accident, caught in fishing nets or cut by boats' propellers. Turtles also are threatened by water pollution, including plastic and trash. Fortunately, many people are working to help sea turtles survive.

The Caribbean Conservation Corporation (CCC) works to protect sea turtles in Costa Rica and in other parts of the Caribbean. The group puts electronic tags on the turtles and uses satellites to track where they go. You can keep track of where the tagged sea turtles go, too!

Space Junk

Everything seemed normal in space. Astronauts were hard at work on the International Space Station. Suddenly, alarms sounded. Mission Control ordered them to abandon the station. They rushed to the escape pod, where they waited for further orders. What was the emergency?

A small piece of space junk was speeding toward the space station at 28,000 kilometers (17,500 miles) per hour. Mission Control feared it would slam into the station. Ten minutes later, Mission Control sent an all-clear order. Phew! The station was safe.

Space Scraps

This close call happened on March 12, 2009. It wasn't the first time space junk threatened astronauts' lives. And it won't be the last. I know. I've been interested in trash since I was 12 years old. I don't mean the trash that's lying around your bedroom that makes your parents mad. I mean the trash that's littering the space around our planet.

We put a lot of trash in space. Each year, we add more. It's sort of like space trash is out of sight, so it is out of mind. Yet space junk has caused a lot of problems.

The first artificial satellite was launched in October 1957. Since then we have launched thousands of satellites. I used one of them to hunt for black holes. Many are still in orbit. Only one in five still work. The rest are junk. Satellites come in many shapes and sizes. Some are as large as a school bus. Despite their size, most aren't that dangerous. They are large enough to track. We can map where they are.

Space Waste

Burned-out satellites are just one kind of space junk. Rockets streak through space to place satellites there. Usually one section of a rocket ends up staying in space, too.

These once valuable rockets now are part of a growing band of space waste. Many still contain rocket fuel that can explode. If one blows up, it can splinter into hundreds of small pieces. Each one of those small pieces adds to the amount of space junk.

Some space junk already has been smashed into smaller pieces. The United States and the former Soviet Union used to test weapons by destroying old satellites. These target satellites shattered into hundreds of small pieces.

China did the same thing a few years ago. One of its missiles crashed into a large weather satellite. The missile and satellite shattered into many pieces, becoming the single worst case of space littering—ever. So far, scientists have counted more than 2,800 pieces.

Leftover Litter

Space junk even can make more space junk. Just last year, a broken Russian satellite smashed into a working U.S. satellite. What happened? Both satellites exploded into a lot more space junk.

The smash-up littered space with more than 1,600 large pieces and countless smaller ones. Each of these pieces threatens the astronauts who bravely work in space. Each piece could also destroy working satellites.

With each new space mission, it seems like more and more small pieces of space junk pile up. Some of this trash winds up there accidentally. Others are put there on purpose.

Missing tools, lost screws, dropped gloves, and chipped paint all can become space junk. So can regular trash. Russian cosmonauts on a space station threw away trash by tossing it into space. As a result, about 300,000 pieces of space junk larger than one centimeter (about half an inch) now litter space.

Small Scraps, Big Damage

All this trash can cause problems. Objects orbiting Earth the same distance as the International Space Station whip through space at 7.7 kilometers (almost five miles) per second. At that speed, an object the size of a nickel packs the same wallop as a car going 80 kilometers (50 miles) per hour.

This can cause lots of damage. Space trash has cracked windows. It has chipped heat shields. It has ripped holes in solar panels. Nothing orbiting Earth is safe from this debris. Space junk also threatens Earth. On average, one piece of junk falls back to Earth each day. Friction with particles in Earth's atmosphere causes most of this stuff to burn up in the air. Big pieces slam into the ground or splash into the oceans. Luckily, only one person has been hit by falling space junk. She was not hurt.

To protect astronauts and valuable satellites, scientists track space junk. By using radar and telescopes, they can track pieces of trash larger than a grapefruit. This allows scientists to keep tabs on 19,000 pieces of junk. This is only the largest space waste, though. Millions of pieces are much smaller. These small scraps can do big damage. Yet there is no way to know where they are.

Shields Up

What can be done about space trash? A good first step is to make less of it. Scientists are designing tools that are harder to lose. For example, it can be easy for an astronaut to drop a camera lens cap. It's harder to lose the cap if it is tied to a camera.

A rocket can use its leftover fuel. That keeps the rocket from blowing up and making even more trash. Special shields can protect astronauts and spacecraft, too. Astronauts wear spacesuits with a layer of bullet-proof material. This protects them from small pieces of trash, which could slice through their suits.

Collecting Trash in Space

Making less trash and protecting astronauts are only the first steps. We know that the junk already in space is very dangerous. Currently, about 13,000 close encounters take place between working spacecraft and space junk each week. Worse yet, the junk already in space is making more junk. So something needs to be done.

Scientists are looking for ways to clean up space waste. One idea is to shoot lasers at litter. The lasers would move the litter away from working satellites. The only problem is that Earth's gravity would pull the litter back. So the litter would become a problem again.

New spacecraft also can act like garbage trucks. Nets on these high-flying garbage trucks could catch litter and dump it into Earth's atmosphere. The litter would burn up before hitting the ground. Some of the burning trash might light up the sky.

One thing is clear: Scientists must work together to find solutions. No one country is responsible for cleaning up space. Many countries tossed junk into space. Now we have to clean it up so space is safe!