Galaxy
星系
Can you believe that there are at least 100 billion galaxies in the universe? Yes, there are.
你相信宇宙中至少有1,000亿个星系吗?确实有。
Small galaxies have 10 billion stars and big galaxies have one trillion stars.
小型星系有100亿颗恒星,而大型星系有10,000亿颗恒星。
The universe must be really big!
所以,宇宙一定广袤无垠!
Do you know what galaxies look like?
你知道星系的形状吗?
Some galaxies have elliptical shapes.
有些星系是椭圆形状。
And some galaxies have spiral shapes.
有些星系是螺旋形状。
The Milky Way is a spiral galaxy.
银河系是螺旋星系。
These two shapes are the most common shapes of galaxies.
椭圆和螺旋这两种形状是最常见的星系形状。
But some other galaxies have irregular shapes too.
但也有一些的星系的形状是不规则的。
Can we observe galaxies? Yes!
我们能观测星系吗?当然能!
We can see them if we use a really good telescope.
使用非常好的望远镜就能看到它们。