Extremely low sulfate levels could also explain why the oceans did not freeze , considering that the sun was about 25 percent dimmer .
太古代之时,太阳的强度比现今弱了25%但海洋却未因此冰封,或许硫酸盐浓度太低可以解释这个现象。
However , as the entire moon will cross the penumbra partial shadow of the earth , it will appear significantly dimmer around the time of partial eclipse .