59.By comparison with these familiaryardsticks，the distancesto the galaxies are incomprehensibly large，but they too are made more manageable by using a time calibration，in this case the distance thatlight travels in one year.

与这些熟悉的尺度相比，到太空的距离远得难以理解，但它们也通过使用一个时间的标尺而变得更加容易对付了，在这种情况下是光在一年内走过的距离。

分句1：the distance…

分句2：but they too

分句3：that…

1和2并列

2和3嵌套