VOA科学技术2023--Scientists Identify Polar Cyclone on Uranus

Scientists Identify Polar Cyclone¹ on Uranus²

The seventh planet from the sun, Uranus, is a world surrounded by mystery. Seen up close just once nearly forty years ago by a passing NASA spacecraft, the planet still guards many secrets.

But new observations are providing a fuller understanding of its atmosphere. These observations, made from a telescope located in New Mexico, include the detection of a polar cyclone whose center measures a quarter of Earth's diameter.

Uranus is a kind of planet known as an ice giant, like its planetary neighbor Neptune³. Scientists were able to look more deeply into the atmosphere of Uranus than ever before. And the findings painted a picture of a planet that is more unusual than previously⁴ known.

Alex Akins of NASA's Jet Propulsion Laboratory in California was the lead writer of the research published in Geophysical Research Letters. While Neptune and Uranus are similar, Akins said Uranus "has some pretty unique features."

"It spins on its side. And even then, its magnetic field is still misaligned with its rotational⁵ axis⁶. The atmospheric⁷ circulation and internal heat release appear weaker than Neptune, but there are still a range of ... features and storms that have been observed," Akins added.

Uranus is the third-largest planet in our solar system. It has a diameter of about 50,700 km and is big enough to fit 63 Earths inside it. Uranus orbits the sun at a distance of about 2.9 billion km, almost 20 times further than Earth does. One orbit lasts 84 years.

Its unusual tilt⁸ makes Uranus appear to orbit the sun like a rolling ball.

The researchers used the Very Large Array telescope in New Mexico to see below the clouds at the top of the atmosphere. They found moving air at the north pole that was warmer and drier, evidence of a strong cyclone. Researchers were able to estimate the size of the storm's center but not the entire cyclone's diameter. It is possible that the cyclone was wider than Earth.

The research suggested that polar cyclones⁹ exist on many bodies in our solar system - all the planets except Mercury and Saturn's moon Titan.

Most of the mass of Uranus is a fluid of icy materials - water, methane¹⁰ and ammonia. Uranus is surrounded by two sets of rings and orbited by 27 small moons. Its atmosphere is the coldest of any of the eight planets, including outermost¹¹ Neptune.

Uranus' only close meeting with a spacecraft came when Voyager 2 flew by in 1986.

"There are a lot of unknowns," Akins said about Uranus. "How did it get tilted¹² on its side? Is its interior really 'icier' than the gas giants (Jupiter and Saturn)? ... Why is the pole so much drier than the equator? Are its satellites (moons) ocean worlds?"

Words in This Story

cyclone – n. an extremely large and powerful storm with very high winds that turn around an area of low pressure

unique – adj. used to say that something is unlike anything else

feature – n. an interesting or important part or quality

misaligned – adj. to not be arranged in a line or in proper position

rotational – adj. describes the act or process of moving or turning around a central point

axis – n. the imaginary straight line that something turns around

 

tilt – n. the state of having one side higher than the other

1 cyclone   

n.旋风，龙卷风

参考例句：

• An exceptionally violent cyclone hit the town last night.昨晚异常猛烈的旋风吹袭了那个小镇。
• The cyclone brought misery to thousands of people.旋风给成千上万的人带来苦难。

2 Uranus   

n.天王星

参考例句：

• Uranus is unusual because it is tilted.天王星非常特殊，因为它是倾斜的。
• Uranus represents sudden change and rebellion.天王星代表突然性的改变和反叛。

3 Neptune   

n.海王星

参考例句：

• Neptune is the furthest planet from the sun.海王星是离太阳最远的行星。
• Neptune turned out to be a dynamic,stormy world.海王星原来是个有生气、多风暴的世界。

4 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

5 rotational   

adj.回转的，轮流的

参考例句：

• A synchronous motor drives the measuring bob at a constant rotational speed.同步马达驱动测锤以恒速旋转。
• With some limitations,this is true also of rotational degrees of freedom.在某些限定条件下，这一说法对转动自由度也成立。

6 axis   

n.轴，轴线，中心线；坐标轴，基准线

参考例句：

• The earth's axis is the line between the North and South Poles.地轴是南北极之间的线。
• The axis of a circle is its diameter.圆的轴线是其直径。

7 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

8 tilt   

v.(使)倾侧；(使)倾斜；n.倾侧；倾斜

参考例句：

• She wore her hat at a tilt over her left eye.她歪戴着帽子遮住左眼。
• The table is at a slight tilt.这张桌子没放平，有点儿歪.

9 cyclones   

n.气旋( cyclone的名词复数 )；旋风；飓风；暴风

参考例句：

• The pricipal objective in designing cyclones is to create a vortex. 设计旋风除尘器的主要目的在于造成涡旋运动。 来自辞典例句
• Middle-latitude cyclones originate at the popar front. 中纬度地区的气旋发源于极锋。 来自辞典例句

10 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

11 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。

12 tilted   

v. 倾斜的

参考例句：

• Suddenly the boat tilted to one side. 小船突然倾向一侧。
• She tilted her chin at him defiantly. 她向他翘起下巴表示挑衅。