translation.en: We know now that the universe is made of about 100 billion galaxies that are visible to us, and each one of those galaxies has 100 billion stars within it.
translation.zh: 现在我们知道了宇宙有大约1000亿个星系， 这仅仅是我们可探测到的。 而每一个星系中都有约1000亿颗恒星。