VOA慢速英语2020 彗星Neowise经过地球时上演灯光秀（在线收听）

Comets are solar system objects made up of ice, rock and dust.Right now, a newly-discovered one is speeding by Earth, providing excellent light shows for the planets people.

彗星是由冰、岩石和尘埃组成的太阳系天体。现在，一颗新发现的彗星正从地球上方疾驰而过，为地球上的人们提供了绝佳的光影秀。

The ice-rock is called Neowise. It is the brightest comet to appear above the Northern Hemisphere in 25 years.

这种冰岩被称为Neowise。它是25年来出现在北半球上空最明亮的彗星。 

Social media users in many countries have posted images they captured of Neowise, as it lit up the sky over their heads.

许多国家的社交媒体用户都上传了他们拍摄的Neowise的照片，照片中它照亮了他们头顶的天空。 

Comets are normally about 8 to 16 kilometers wide.But, as they travel near the sun, they heat up, releasing gas and dust.

彗星通常宽8到16公里。但是，当它们靠近太阳时，它们会升温，释放气体和尘埃。 

The comet expands to form a "glowing head that can be larger than a planet," says the U.S. space agency NASA.

NASA（美国宇航局）说，这颗彗星膨胀成一个“比行星还要大的发光体”。 

The process also creates a sunlit "tail" of dust. It can stretch for millions of kilometers behind the comet.

这个过程也产生了阳光照射下的尘埃“尾巴”。它可以在彗星后面延伸数百万公里。 

Scientists say Neowise is believed to be about 5 kilometers across.

科学家表示，Neowise的直径约为5公里。 

It passed inside Mercurys orbit on July 3, NASAs Jet Propulsion Laboratory said in a statement.

NASA喷气推进实验室在一份声明中称，它于7月3日进入水星轨道。 

The close pass by the sun was "cooking" the comets outermost parts, causing a major release of gas and dust material.

近距离经过太阳的过程正在“炙烤”彗星的最外层，导致气体和尘埃物质大量释放。 

"And yet the comet has managed to survive this intense roasting," the statement said.

声明中说:“然而，这颗彗星在这种强烈的烘烤中幸存了下来。” 

The comet was named for NASAs NEOWISE infrared space telescope, which discovered it in March.

这颗彗星以NASA的NEOWISE红外太空望远镜命名，该望远镜于今年3月发现了这颗彗星。 

The NEOWISE project aims to search the skies for what scientists call near-Earth objects, or NEOs.

NEOWISE项目的目标是搜索天空中被科学家称为近地天体的物体。 

Such objects include asteroids and comets that could come within 50 million kilometers of Earths orbit.

这类天体包括小行星和彗星，它们可能距离地球轨道5000万公里以内。 

In this case, NASA said Neowise would pass by Earth "at a harmless distance of 103 million kilometers," while giving astronomers a good chance to study its substance and structure.

在这种情况下，NASA说Neowise将会以“1.03亿公里的安全距离”经过地球，同时给天文学家一个很好的机会来研究它的物质和结构。

Sky watchers may be able to see Neowise as it passes through the inner solar system.

当Neowise穿过太阳系内部时，天空观测者也许能够看到它。 

But "its nearness to the sun" could make sighting it difficult, NASA says.

但是NASA说，“它离太阳很近”，这使得对它的观测变得很困难。 

Experts say people in the Northern Hemisphere - the part of Earth above the equator - should look toward the northwestern sky, just below the "Big Dipper" star group.

专家说，生活在北半球的人（地球在赤道上方的那部分）应该向西北方向看，就在“北斗七星”下方。

Until recently, the best time to see Neowise was about an hour before sunrise.

直到最近，观赏Neowise的最佳时间是日出前一个小时左右。 

This week, the comet began making its appearance in the evening sky shortly after sunset.

本周，这颗彗星在太阳落山后不久出现在夜空中。 

People have been able to see the head of the comet without the use of equipment.

人们不用设备就能看到彗星的头部。 

But devices like binoculars and telescopes are better for viewing the comets long tail.

但是像双筒望远镜和望远镜这样的设备更适合观察彗星的长尾巴。 

Neowise is expected to be seeable across the Northern Hemisphere until mid-August.

预计到8月中旬，整个北半球都可以看到Neowise。 

It will then start making its way back to the outer parts of the solar system.

然后它将开始返回太阳系的外部。 

NASA says it will be about 7,000 years before the comet returns."So I wouldnt suggest waiting for the next pass," said Joe Masiero of NASAs Jet Propulsion Laboratory.

NASA表示，这颗彗星大约需要7000年才能返回地球。NASA喷气推进实验室的乔·马西罗说:“所以我不建议等待下一次通过。”

Astronauts on the International Space Station caught a good look at the bright ice-rock last week.

上周，国际空间站的宇航员很好地捕捉到了这块明亮的冰岩。 

NASAs Bob Behnken captured an image of Neowise and shared the picture on social media.

NASA的鲍勃·贝恩肯抓拍到了Neowise的照片，并在社交媒体上分享了这张照片。 

It shows central Asia in the background, and part of the space station in the foreground.

它的背景是中亚，前景是空间站的一部分。 

"Stars, cities, spaceships, and a comet!" Behnken tweeted from orbit.

“星星、城市、宇宙飞船和一颗彗星!”贝恩肯在轨道上发推特说。 

Im Bryan Lynn.

布莱恩·林恩报道。