VOA科学技术2023--NASA Spacecraft Studying Sun Discovers New Details about Solar Wind

NASA Spacecraft Studying Sun Discovers New Details about Solar Wind

Scientists say a spacecraft flying very close to the sun has uncovered new details about the nature of solar wind.

Solar wind is created by a continuous flow of charged particles, known as plasma¹, that are released into space from the sun's outermost² atmosphere. That atmosphere is known as the corona³.

Researchers recently announced they had learned new information about solar wind from data collected by the Parker Solar Probe. The American space agency NASA operates the spacecraft.

NASA launched the Parker Solar Probe in 2018 with a main goal of studying solar wind. Scientists say studying solar wind and the corona close up is important to learn how solar activity influences Earth.

Unlike Earth, the sun does not have a solid surface. Instead, it is a superheated ball of material held together by gravity and magnetic forces. Some solar material escapes from the sun and is released into space as solar wind.

In 2021, researchers announced that the Parker Solar Probe had entered the sun's corona for the very first time. NASA described the successful operation as "touching⁴" the sun. Scientists said Parker was about 13 million kilometers from the center of the sun when it crossed into the sun's outer atmosphere.

Data collected by the spacecraft showed that solar wind can reach speeds up to 1.6 million kilometers per hour. Solar wind forms a large magnetic barrier known as the heliosphere. It protects Earth and other planets from the continuous flow of high-energy particles from the sun's corona.

The researchers recently reported their findings in a study published in Nature.

The team said the collected data suggests these particles get blasted from the sun in a similar way that water shoots out from a shower head. The particles are released through holes in the sun's corona. The researchers said the data suggests these openings are the source of solar wind.

Past research had found that the sun's magnetic field was somehow driving solar wind. This study is the first to identify its source.

James Drake is a professor of physics at the University of Maryland and a lead writer of the study. He said in a statement, "Winds carry lots of information from the sun to Earth, so understanding the (source) behind the sun's wind is important for practical reasons on Earth."

Drake said that understanding how the sun releases energy can help scientists learn how to prepare for solar storms that can affect Earth. For example, intense solar activity can cause solar flares⁵, explosions of electromagnetic radiation from the sun. This can interfere⁶ with different radio communication signals on Earth.

The researchers said the data showed that the holes in the sun's corona are usually in areas around the poles during the sun's quiet periods. This prevents the speeding particles from affecting Earth.

However, the team noted⁷ that the sun becomes active every 11 years as its magnetic field changes and the poles exchange positions. This results in "bursts of solar wind aimed directly at Earth," the researchers said in a statement.

The researchers used data from the Parker Solar Probe to examine plasma flowing out of the corona. Data for the latest research was collected at a distance of about 9 million kilometers from the sun, the team said.

"When you get very close to the sun, you start seeing stuff that you just can't see from Earth," Drake said. He added that the findings were only possible because the Parker Solar Probe was able to pass so close to the surface of the sun. "We're about as close as we're going to get," Drake said.

Words in This Story

blast – v. an explosion or violent detonation⁸

shower – n. a piece of equipment that shoots out water and is used to clean the body

source – n. where something comes from

practical – adj. able to be done successfully

1 plasma   

n.血浆，细胞质，乳清

参考例句：

• Keep some blood plasma back for the serious cases.留一些血浆给重病号。
• The plasma is the liquid portion of blood that is free of cells .血浆是血液的液体部分，不包含各种细胞。

2 outermost   

adj.最外面的，远离中心的

参考例句：

• He fired and hit the outermost ring of the target.他开枪射中了靶子的最外一环。
• The outermost electron is shielded from the nucleus.原子核对最外层电子的作用受到屏蔽。

3 corona   

n.日冕

参考例句：

• The corona gains and loses energy continuously.日冕总是不断地获得能量和损失能量。
• The corona is a brilliant,pearly white,filmy light,about as bright as the full moon.光环带是一种灿烂的珠白色朦胧光，几乎像满月一样明亮。

4 touching   

adj.动人的，使人感伤的

参考例句：

• It was a touching sight.这是一幅动人的景象。
• His letter was touching.他的信很感人。

5 flares   

n.喇叭裤v.（使）闪耀( flare的第三人称单数 )；（使）（船舷）外倾；（使）鼻孔张大；（使）（衣裙、酒杯等）呈喇叭形展开

参考例句：

• The side of a ship flares from the keel to the deck. 船舷从龙骨向甲板外倾。 来自《简明英汉词典》
• He's got a fiery temper and flares up at the slightest provocation. 他是火爆性子，一点就着。 来自《现代汉英综合大词典》

6 interfere   

v.(in)干涉，干预；(with)妨碍，打扰

参考例句：

• If we interfere, it may do more harm than good.如果我们干预的话，可能弊多利少。
• When others interfere in the affair,it always makes troubles. 别人一卷入这一事件，棘手的事情就来了。

7 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

8 detonation   

n.爆炸；巨响

参考例句：

• A fearful detonation burst forth on the barricade.街垒传来一阵骇人的爆炸声。
• Within a few hundreds of microseconds,detonation is complete.在几百微秒之内，爆炸便完成了。