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

如此来，就会得到理想的肥皂泡星。

This is an emission nebula located just below Orion's belt.

这位于户星带下方的发射星。

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

在很多星中并没有尖锐的边缘；它们只会慢慢消失。

But sometimes nebulae do have sharp edges.

但有时星确实有锋利的边缘。

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

但开始这星或多或少更像个不成形的水滴。

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

户星种特殊星，叫做恒星摇篮。

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

他看到了无数星团，明亮的星，甚至还看到了整个银河！

That's a very common shape for planetary nebulae.

这行星状星很常见的形状。

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。

The most famous is the Crab nebula, from a star we saw blow up in the year 1054.

其中最著名的蟹状星，它来自于我们在1054年看到的恒星爆炸。

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气体和尘埃——也就星。

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

户剑的位置有户星，种由尘埃、氢气、氦气及其他气体组成的。

Today you learned that nebulae are clouds of gas and dust in space.

今天你们知道了星太空中的气体和尘埃。

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

这些也可以在星中创造出可爱的片状、卷须和丝状物。

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，即大团富含化学物质的团飘逸在宇宙之中。

So planetary nebulae really may owe their existence to planets!

所以行星状星的存在可能真的要归功于行星！

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

户星宇宙中的奇迹之。

At the centre of the nebula lies the remnant of the star, its core, crushed by the force of gravity.

在星的中心处，这颗恒星的星核依然存在着，在引力的作用下它已面目全非。

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。

For example, Shapley noted that one of the spiral nebulae had been seen to rotate, so it must be small.

例如，沙普利注意到个螺旋状星在旋转，所以它定很小。