When that happens, you get that idealized soap bubble nebula.

如此来，就会得到理想的肥皂泡星云。

That's a very common shape for planetary nebulae.

这是行星状星云很常见的形状。

The orion nebula is a special kind of nebula called a stellar nursery.

座星云是种特殊星云，叫做恒星摇篮。

In a lot of nebulae there's no sharp edge; they just kinda fade away.

在很多星云中并没有尖锐的边缘；它们只是会慢慢消失。

Those elements will spread out to become a nebula, a rich chemical cloud drifting through space.

这些物质最后会扩散开来，形成新的星云，即大团富含化学物质的云团飘逸在宇宙之中。

But sometimes nebulae do have sharp edges.

但有时星云确实有锋利的边缘。

Orion's sword is home to the great orion nebula, a cloud of dust, hydrogen, helium, and other gases.

剑的位置有座星云，是种由尘埃、氢、氦及其他成的云。

He saw clusters of stars, brightly colored nebulas, even entire galaxies!

他看到了无数星团，明亮的星云，甚至还看到了整个银河！

These can create lovely sheets, tendrils, and filaments in nebulae as well.

这些也可以在星云中创造出可爱的片状、卷须和丝状物。

However, this nebula started off more or less as a big shapeless blob.

但是开始这星云或多或少更像个不成形的水滴。

It is a nebula: a star-forming region where new stars are being born.

个正在诞生新恒星的恒星形成区域。

Gas inside a nebula can be in turmoil, too.

星云内的也可能处于混乱状态。

So planetary nebulae really may owe their existence to planets!

所以行星状星云的存在可能真的要归功于行星！

The Orion nebula is one of the wonders of the universe.

座星云是宇宙中的奇迹之。

Among the other four images were two that showed huge clouds of gas and dust – called nebulas.

在其他四张照片中，有两张展示了巨大的和尘埃云——也就是星云。

This object is what we call a planetary nebula.

这个物就是我们所说的行星状星云。

Everything we find on the Earth today also originated in that nebula.

我们地球上的切也都来源于那片星云。

That usually happens when a gas cloud is expanding, like in a planetary nebula or supernova.

这通常发生在云膨胀时，比如行星状星云或超新星。

Stars, nebulae, stellar clusters of various sorts, the occasional supernova.

恒星、星云、各种类型的星团，偶尔还有超新星。

Not too far from the Orion Nebula in the sky is another dark nebula, superposed on a bright emission nebula.

天空中离座星云不远的地方是另个暗星云，它叠加在个明亮的发射星云上。