VOA慢速英语2009年-SCIENCE IN THE NEWS - Arctic Sea Ice Shrin（在线收听）

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty.

VOICE TWO:

And I'm Barbara Klein. This week, we will tell the latest about sea ice in the Arctic Ocean. We will also tell about an international competition involving solar-powered houses. And, we will tell about a new public observatory in Washington, DC.

(MUSIC)

VOICE ONE:
　
Arctic sea ice on the Chukchi Sea

The warmest season in the Arctic Ocean could never be described as warm. Yet some sea ice in the Arctic melts each year during summer in the Northern Hemisphere. Then it freezes again in the winter. The total of sea ice is known as the sea ice extent. The ice is important because it helps keep the Arctic cold and reduces extremes in the Earth's climate.

Experts say the Arctic sea ice extent is under threat. But there is some good news about the extent, at least for now. Scientists say a little more ice covered the Arctic in September than in September of two thousand eight. The scientists work for the National Snow and Ice Data Center at the University of Colorado in Boulder.

September is the month when the sea ice extent is at its lowest. The scientists say the average Arctic sea ice extent last month was about five million square kilometers. This was more than one million square kilometers more than the record low for September. The record low was set in two thousand seven.

VOICE TWO:

Mike Steele is an ocean expert at the University of Washington in Seattle. He says sea surface temperatures in the Arctic were higher than normal last month. But skies were cloudy during the summer. That caused lower temperatures, which slowed loss of ice. Atmospheric conditions in August and September also helped to spread the ice. They kept the sea ice extent higher.

Still, the National Snow and Ice Data Center says the most recent September measurement was the third lowest since nineteen seventy-nine. The center says September Arctic sea ice is decreasing at a rate of more than eleven percent every ten years. In the winter months, it is falling by about three percent every ten years.

VOICE ONE:

The center's director, Mark Serreze, says it is good to see what he calls, a little recovery. But he says there is no reason to think that the ice levels will return to the levels of thirty years ago. He warns that the Arctic Ocean could be free of ice during future Northern Hemisphere summers.

The report also says the two thousand nine ice cover was thin. This means it might melt in future summers. The scientists say that ice formed less than one year earlier covered almost half of the extent.

(MUSIC)

VOICE TWO:

On a cold weekend this month, thousands of people waited in the rain to visit twenty unusual buildings set up in the heart of Washington, DC. They gathered to see buildings that get all the power they need from the sun. But these structures were not just about solar power. They offered visitors a chance to step into the future of home design and household technology.

The houses were entered in the Two Thousand Nine Solar Decathlon. The United States Department of Energy organized the event. It brought together teams representing twenty universities from Canada, Germany, Spain and the United States. The main goal was to create beautiful homes that can meaningfully cut energy use.

VOICE ONE:

The competition was first held in two thousand two and has taken place every two years since two thousand five. Teams sent proposals to the Department of Energy, which accepted twenty for the Decathlon. The Department gave one hundred thousand dollars to each of the accepted teams to start their projects. But there was no spending limit. The final houses cost from about two hundred thousand dollars to over eight hundred thousand dollars to make.

Each house had about two hundred forty square meters of floor space. The idea was to design great places to live. Architecture students developed designs that were imaginative and effective. Some used natural materials like wood on the outside of the house for a pleasing appearance. Others created strikingly modern buildings like Spain's entry. It was covered with a moving roof that kept its solar panels pointed toward the sun.

VOICE TWO:
　
The winning entry from Germany

The winning entry came from the Technical University of Darmstadt, in Germany. The design of its house stood out from all the others. It looked like a black cube. Tabea Huth helped design the German entry. She shared its secret with us.

TABEA HUTH: "Most of the people who come along here didn't notice that we have solar panels around the fa?ade. They thought it's just glass."

VOICE TWO:

In fact, the outer surface of the German entry was covered with solar panels. Because of this, the house was able to create more electricity than any other design.

VOICE ONE:

Judges rated ten areas of design and use. Entries were judged on their architectural qualities. They were also judged on their marketability, engineering and lighting design. Other areas included how well the teams communicated their ideas.

Each team had to create a design that could keep the inside of the house at a temperature of between twenty-two and twenty-four degrees Celsius. Hot water had to be available throughout the day. Teams were also required to operate appliances like washing machines and dishwashers during the competition.

Each house had an operating home entertainment system. The designs had to show that the sun could power the electronic equipment people depend on for both work and play.

VOICE TWO:
　
The entry by the University of Illinois at Urbana-Champaign

The second place winner came from the University of Illinois at Urbana-Champaign. This house required less energy and limited waste better than any other design. The walls were built extra thick to save heat and energy-efficient appliances kept energy use low.

Britta Monson is a student at the University of Illinois.

BRITTA MONSON: "I think the most important thing about the house is just how much energy it really does conserve. And how the systems that we have designed for the house and we've used for the house how efficient they are and how little energy they use."

VOICE TWO:

The Illinois team led for much of the competition. But with fewer solar panels, they fell behind the German team on the most important requirement: energy production. Both teams, however, were able to provide more than enough energy to meet the requirements of the competition. They even produced surplus electricity.

Next year, the solar decathlon will be held in Madrid, Spain. Then, in two thousand eleven, the Solar Decathlon will return to Washington.

(MUSIC)

VOICE ONE:

Finally, there is a new activity on the National Mall in Washington. An observatory opened recently at the Smithsonian Institution's National Air and Space Museum. About two thousand people visited the Public Observatory Project in the first two weeks after it opened.

The project honors two thousand nine as the International Year of Astronomy. This year also marks the four hundredth anniversary of the first recorded astronomical observations with a telescope by Galileo.

Historians say the Italian scientist and mathematician may not have been the first to get a good look at the moon and planets. But he probably was the first to let the world know about it.

VOICE TWO:
　
The Smithsonian's Public Observatory

The new observatory is the home of a forty-centimeter telescope. The telescope weighs about one thousand three hundred sixty kilograms. It is on loan from the Smithsonian's Astrophysical Observatory for two years.

Some visitors are surprised that the Public Observatory Project operates only during daytime hours. They are even more surprised when they learn how much they can see during the day.

David DeVorkin works for the National Air and Space Museum. He says visitors using the telescope have seen bright stars.

DAVID DEVORKIN: "The nicest thing is you can still see their colors. There's enough contrast so that you can tell the difference between a red star and a blue star and show people that stars have colors. All of that you can do during the day."

VOICE TWO:

Mister DeVorkin says the observatory is meant to appeal to visitors who have not been interested in astronomy before. He says one way of doing so was to provide a fully-equipped telescope. He says he dreamed of placing just such an instrument on the National Mall.

(MUSIC)

VOICE ONE:

This SCIENCE IN THE NEWS program was written by Mario Ritter and Jerilyn Watson. Our producer was Brianna Blake. I'm Bob Doughty.