VOA标准英语2012--Rare Astronomical Event to Occur June 5-6

 

Rare Astronomical¹ Event to Occur June 5-6

 

Skywatchers on all seven continents will get a chance to witness an astronomical rarity on June 5 or 6, the transit² of the planet Venus. It is likely the last time anyone alive today will have a chance to view one.

That's because after this year's transit of Venus, the next one is in 2117.

Transits³ of Venus have happened only six times since the phenomena⁴ was first observed with a telescope in 1639, and only once since the invention of the television.

People around the world turned out in 2004 to watch as Venus passed across the face of the sun - seen from Earth for the first time since 1882.

Venus appeared in silhouette⁵, casting a small black dot on the sun.

It's an uncommon⁶ event, but not necessarily a spectacular one.

"What actually happens to the casual person who doesn't know it's happening is nothing," explains David DeVorkin, the senior curator of the history of astronomy at the Smithsonian National Air and Space Museum in Washington. "Okay, there won't be any change in the brightness of the sky and, you know, birds won't come home to roost or anything like that. But if you know it's happening, it's really quite interesting." 

The event is interesting, in part, because it is so rare. Transits occur in pairs, and the pairs are separated by more than a century. The upcoming transit bookends the transit of 2004.

"If you're looking safely at the sun, you will see a spot appear on the edge of the sun that is about 1/30th the size of the disc of the sun itself, and over a few hours' time, it's simply going to drift across the sun and keep going," DeVorkin says. 

The key, as DeVorkin notes, is to view safely. You should not stare directly at the Sun, but you can use glasses and telescopes with protective filters.

Scientists in previous centuries used the transits to answer questions about the solar system.

"Astronomers⁷ realized way back in the 17th century that if you could very accurately⁸ time this appearance of Venus going across the sun, and time it as accurately as you can from two widely different parts of the Earth, you could use the different timings to triangulate to find out how far we are from the sun, and that was a fundamental question," says DeVorkin.

Scientists, astronomers and adventurers, including famed British explorer Captain James Cook, launched expeditions to observe and gather data about the transit pair in the 1760s. 

 

1 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。

2 transit   

n.经过，运输；vt.穿越，旋转；vi.越过

参考例句：

• His luggage was lost in transit.他的行李在运送中丢失。
• The canal can transit a total of 50 ships daily.这条运河每天能通过50条船。

3 transits   

通过（transit的复数形式）

参考例句：

• The anomalistic year is the time between successive transits of the Earth through the perihelion. 近点年是地球连续两次通过近日点之间的时间。
• Paradigm study gradually transits to exemplification study in civil society theory. 当前我国的市民社会理论正逐步从范式研究转向范例研究。

4 phenomena   

n.现象

参考例句：

• Ade couldn't relate the phenomena with any theory he knew.艾德无法用他所知道的任何理论来解释这种现象。
• The object of these experiments was to find the connection,if any,between the two phenomena.这些实验的目的就是探索这两种现象之间的联系，如果存在着任何联系的话。

5 silhouette   

n.黑色半身侧面影，影子，轮廓；v.描绘成侧面影，照出影子来，仅仅显出轮廓

参考例句：

• I could see its black silhouette against the evening sky.我能看到夜幕下它黑色的轮廓。
• I could see the silhouette of the woman in the pickup.我可以见到小卡车的女人黑色半身侧面影。

6 uncommon   

adj.罕见的，非凡的，不平常的

参考例句：

• Such attitudes were not at all uncommon thirty years ago.这些看法在30年前很常见。
• Phil has uncommon intelligence.菲尔智力超群。

7 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》

8 accurately   

adv.准确地，精确地

参考例句：

• It is hard to hit the ball accurately.准确地击中球很难。
• Now scientists can forecast the weather accurately.现在科学家们能准确地预报天气。