In the outer part of that shadow, the penumbra, part of the Sun, is blocked.

而影子外面部分的半影, 被太阳的一部分。

But as the Moon moves deeper into the penumbra, it starts to darken.

不过随着月亮更加深入半影区域，它就越来越暗。

This region is called the “penumbra” ; “pen” in this case for Latin meaning “almost, ” or “nearly.”

这个区域被称为半影（penumbra）；这里英文中的“pen”的拉丁文意思是“大致”或“几乎”。

Here's the penumbra, a partially shaded outer region surrounding the umbra, a fully shaded inner part that's darkened.

这是半影区，一个包围了本影区的外部区域，本影区是一个完全黑暗的内部区域。

The wider outer shadow, where the Earth is only partially blocking the sun’s light, is called the penumbra.

范围较广的外部阴影内，能遮部分阳光，这一部分称之为半影。

If you're standing within the swath traced by the penumbra, as it moves along the Earth's surface, then you'll see only a partial eclipse.

如果你站在半影的区域里，当它沿着表面移动时，你就能看到日偏食。

When the Moon first enters the Earth's penumbra, the dimming is so slight you hardly notice it.

当月亮刚进入的半影时，亮度有轻微的减弱，以至于你很难注意到。

A partial eclipse occurs when the sun, moon, and Earth are not perfectly aligned so that the penumbra, or lighter outer portion of the moon's shadow, falls on the earth.

当太阳、月亮和三者没有完美形成直线时，月亮的半影也就是亮的那部分照射在上。

First, the edge of the Moon slips in front of the Sun, and we see a little dip in the Sun's limb, its edge as seen from Earth (that's the start of the penumbra sweeping over you).

首先，随着月的边缘进入太阳正面，我们会看到太阳缺了一点点（这表示半影开始扫过你）。