2007年VOA标准英语-NASA Reveals New Sun Phenomena(在线收听

By Paul Sisco
Washington
30 March 2007
 
watch NASA Sun Study

Several times each year, scientists and administrators at the US. Space Agency's headquarters in Washington, unveil their most recent discoveries and activities, and plans. VOA's Paul Sisco attended the first NASA Science Update of the year, and reports on the space agency's latest discoveries about the sun.

 
Images of the sun's surface
This is an image of the surface of the sun, and its sunspots, in detail never before seen.  NASA says the images clearly show the sun's magnetic field is much more violent than previously thought.

The images come to us thanks to mission Hinode, which loosely means sunlight in Japanese. 

Launched from Japan last September, the Hinode spacecraft carries multiple instruments that, from orbit, make continuous observations of the sun.

 "Soon after the telescope opened, we saw a very large sun spot, and you can see an accompanying sun spot," astrophysicist, Alan Title explains.  "Where its white magnetic field is coming out of the sun and where its black magnetic field is going into the sun, so it's a kind of magnetic hurricane."

To put this into context, that top white spot is about 25% larger than the diameter of the earth. And each one releases roughly the equivalent of all the energy that could be generated by all the power plants on earth for hundreds of years.

 
Leon Golub

Scientist Leon Golub designed an instrument that records powerful x-ray's released from the sun.

"The x-ray eruption starts with a large magnetic loop that collapses downward and then everything erupts upward after that," he explains.  "This hasn't been seen before, is totally unexpected and as far as I'm concerned, is impossible."

At least there is no explanation for the phenomenon yet. 

The scientists say they are receiving data and images from the spacecraft, almost every day, unlike any they have seen before.

"There are many, many things coming down in the data that have that character, totally unexpected and clearly they are going to change our views once we figure out what's going" Golub says.

 
'Chaotic dynamo' sun magnetic field
This is another process on the sun's surface, never recorded before. It's called a chaotic dynamo, and is believed to have something to do with the magnetic field found in sunspots.'

 "From essentially day one, when we took data, we had data that changed the way we thought," Title says. " And since then it is painful to leave my office, because everyday when I come in the morning I want to see what we discovered last night and we have not shown you some of the most sensational stuff."

The ongoing Hinode mission is an example of successful collaboration between the space agencies of Japan, the United States, the United Kingdom and Europe.

  原文地址:http://www.tingroom.com/voastandard/2007/3/37879.html