VOA慢速英语--木星和土星将在夜空中相遇

The planets Jupiter and Saturn¹ have been moving closer and closer to each other in the night sky. In fact, on December 21, they appear closer together than they have in hundreds of years.

When two astronomical² bodies appear close in the sky, as seen from Earth, it is called a conjunction. Conjunctions can happen with any two bodies, such as planets, moons, stars and asteroids³. When Jupiter and Saturn come together, it is called a "Great Conjunction."

Astronomers⁵ say these events between the two largest planets in our solar system are not especially rare. Jupiter passes its neighbor Saturn once every 20 years as they circle around the sun.

But this conjunction is especially close: From Earth, the two planets will look to be just one-tenth of a degree apart. That is about the distance of one-fifth of a full moon.

If weather permits, they should be easy to see just after sundown. This just-in-time-for-Christmas sight promises to be one of the greatest of Great Conjunctions.

David Weintraub is an astronomy professor at Vanderbilt University. He told The Associated Press that a close conjunction that happens in our nighttime sky is very rare.

"I think it's fair to say" that such an event usually may happen "just once in any one person's lifetime," he said. "And I think ‘once in my lifetime' is a pretty good test" of whether something should be considered rare or special.

The Jupiter-Saturn conjunction has not been this close since July 1623. But, back then, the positioning was almost impossible to see because of its closeness to the sun.

What makes this modern "Great Conjunction" special is it is happening at nighttime. The last time that happened was almost 800 years go. The year was March 1226. Around that time, warrior-ruler Genghis Khan was conquering Asia.

Saturn and Jupiter have been getting closer in the south-southwest sky for weeks. Jupiter, which is bigger and closer to Earth, is much brighter.

"I love watching them come closer and closer to each other," said Nahum Arav in an email. He is an astronomer⁴ at Virginia Tech University. He said he loves the fact that he will see with his own eyes from his own home.

The two planets might look like one body if viewed with eyes alone. If sky watchers use binoculars⁶ they should be able to see the planets as separate. Saturn will be the smaller, less-bright body at Jupiter's upper right.

Even though they appear close, more than 730 million kilometers of space lies between them. Observers using telescopes will not only capture Jupiter and Saturn in the same field of view, but also some of their brightest moons.

Their next close pairing will happen March 15, 2080.

Words in This Story

solar system – n. our sun and the planets that move around it

conquer – v. to take control of a country or region through the use of force

binoculars – n. a device that you hold up to your eyes and look through to see things that are far away

1 Saturn   

n.农神，土星

参考例句：

• Astronomers used to ask why only Saturn has rings.天文学家们过去一直感到奇怪，为什么只有土星有光环。
• These comparisons suggested that Saturn is made of lighter materials.这些比较告诉我们，土星由较轻的物质构成。

2 astronomical   

adj.天文学的，（数字）极大的

参考例句：

• He was an expert on ancient Chinese astronomical literature.他是研究中国古代天文学文献的专家。
• Houses in the village are selling for astronomical prices.乡村的房价正在飙升。

3 asteroids   

n.小行星( asteroid的名词复数 )；海盘车，海星

参考例句：

• Asteroids,also known as "minor planets",are numerous in the outer space. 小行星，亦称为“小型行星”，在外太空中不计其数。
• Most stars probably have their quota of planets, meteorids, comets, and asteroids. 多数恒星也许还拥有若干行星、流星、彗星和小行星。

4 astronomer   

n.天文学家

参考例句：

• A new star attracted the notice of the astronomer.新发现的一颗星引起了那位天文学家的注意。
• He is reputed to have been a good astronomer.他以一个优秀的天文学者闻名于世。

5 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

6 binoculars   

n.双筒望远镜

参考例句：

• He watched the play through his binoculars.他用双筒望远镜看戏。
• If I had binoculars,I could see that comet clearly.如果我有望远镜，我就可以清楚地看见那颗彗星。