Rather, they are dark because of interstellar dust that hides the stars behind it.

相反，它们之所以是黑暗的，是因为星际尘埃将恒星隐藏在它的后面。

The interstellar material, rather like terrestrial clouds, comes in all shapes and sizes.

星际物质很像地球上的云，形状大小各异。

Optical astronomy is most directly affected, for although interstellar gas is perfectly transparent, the dust is not.

光学天文学受到最直接的影响，因为虽然星际气体是完全透明的，但尘埃却不是。

The average density of interstellar material in the vicinity of our Sun is 1,000 to 10,000 times less than the best terrestrial laboratory vacuum.

在我们的太阳附近，星际物质的平均密度比最好的地球实验室真空还要低1000到10000倍。

IS INTERSTELLAR DUST VISIBLE FROM EARTH?

在地球上可以看到星际尘埃吗？

Innovations and the Future of Interstellar propulsion.

星际推进器的革新和展望。

WIDE ANGLE: Project Icarus: Reaching for Interstellar space.

广角：伊卡洛斯项目：延伸到星际空间。

Scientists think it will enter interstellar space in about four years.

科学家相信四年内它将进入星际空间。

But for other astronomers, interstellar dust is useful in its own right.

但对于其他天文学家而言，星际尘埃自身确是有用的。

Interstellar Medium: What astronomers call all that stuff between the stars.

星际介质：即天文学家所称的恒星间的物质。

It would have run afoul of Jupiter and been chucked into interstellar space.

他可能与木星运行相冲突并被抛到了星际空间。

The interstellar cloud of gas and dust is an active star-forming region.

由气体和尘埃组成的星系云是一个恒星形成的活跃区域。

Light and radio waves are absorbed and scattered by interstellar gas and dust.

光波和无线电波能被星际气体和尘埃吸收及散射。

Inside the head of this interstellar monster is a star that is slowly destroying it.

在这星际怪物的顶端内部是一颗正在慢慢摧毁它的恒星。

The shock acts as a searchlight by revealing the structure of the interstellar medium.

冲击波能揭示出星际介质的结构，扮演着探照灯的角色。

This is a prerequisite for having the technical smarts to achieve interstellar travel.

这是拥有可以进行星际航行的技术的先决条件。

A classic dark nebula, the Snake is a tendril of interstellar gas and dust about 650 light years away.

在经典黑暗星云中，蛇是星际气体和尘埃组成的卷须，长约650光年。

Our solar system arose from a large, rotating cloud of interstellar debris called the solar nebula.

太阳系形成于一个巨大的旋转星云——太阳系星云，星云中含有大量的星际残骸。

A continuous broadcast powerful enough to reach across interstellar space takes a huge amount of energy.

持续的广播足够到达星际空间，那要消耗巨大的能量。

Satellites that orbit close to major galaxies eventually forfeit their interstellar gas to the greater galaxy.

那些近距离围绕主要星系轨道运行的卫星最终将它们的星际气云失给了更大的星系。

In order to achieve interstellar travel, Matloff stresses that less mass and more of a solar push are key.

为了实现星际航行，马特罗夫强调，更轻的飞船质量以及更强的太阳光推力是关键。

The heliopause was expected to be a rather sharp boundary between the sun's domain and interstellar space.

太阳风顶层曾被认为是处在太阳系区域和星际宇宙之间一层电磁波动极其强烈的区域。

Elliptical galaxies contain many older stars, up to one trillion, but little dust and other interstellar matter.

椭圆星系中有多达万亿颗古老的恒星，但几乎没有灰尘和其他星际物质。

Kent think he knows why: Perhaps only the wiliest of alien species survive the interstellar version of evolution.

肯特认为他找到了答案：或许只有最为狡诈的外星种族才能挺过从大陆文明向太空文明过渡的挑战。

The resulting image highlights the bright swept-back ridges that outline pockets of cool interstellar dust and gas.

得出的图片突出显示了星际尘埃和气体群的轮廓所形成的明亮的后掠式突起。

The Voyager 1 spacecraft is poised to leave the solar system and reach interstellar space. In fact, it may already have.

航海家1号宇宙飞船随时可能飞出太阳系进入星际空间，事实上，它可能已经做到了。