For context, one astronomical unit is the distance from the earth to the sun, so four hundred astronomical units is about ten times the orbit of pluto.
AU meaning astronomical unit, which is the distance between the Earth and the Sun, which means that Voyager 1 is 138 times further away from us than the Sun is.
AU 是天文单位,是地球到太阳的平均(合 1.496 亿公里),也就是说旅行者 1 号我们的是太阳的 138 倍。
Supermassive black holes have masses from a hundred thousand times the mass of the sun to tens of billions of solar masses and are so big they get as big as four hundred astronomical units.