The inner portion of the shadow cast on Earth by the Moon during a solar eclipse is called the umbra.

Here's why:

* Umbra: This is the darkest part of the shadow, where the Moon completely blocks out the Sun's light. People standing within the umbra experience a total solar eclipse.

* Penumbra: This is the lighter, outer portion of the shadow. Here, the Moon only partially blocks the Sun's light. People standing within the penumbra experience a partial solar eclipse.

So, when you see a picture of a solar eclipse with a dark, narrow path of totality cutting across the Earth, that dark path represents the umbra.