The dark inner shadow where total eclipses can be seen on Earth is called the umbra.

Here's a breakdown:

* Umbra: This is the innermost and darkest part of a shadow. During a total solar eclipse, the umbra is the region where the Moon completely blocks the Sun's light.

* Penumbra: This is the lighter, outer part of a shadow. During a partial solar eclipse, the penumbra is the region where the Moon partially blocks the Sun's light.

So, the umbra is where the total eclipse experience occurs, with the sky becoming very dark and the solar corona becoming visible.