a: Four types of shadow regions-umbra (U), inner penumbra (P2), outer

a: Four types of shadow regions-umbra (U), inner penumbra (P2

Penumbra Shadow Facts, Information, History, Types, How Dark & When

Penumbra and Umbra

Eclipse Shadow: What Is the Penumbra?

Total Solar Eclipse of 2009 July 22 - NASA Eclipse Web Site

Umbra and Penumbra region of Earth-Sun system.

m1

Reference Section 4

Results of our building detection algorithm which uses the proposed

Umbra, Penumbra, and Antumbra in an Eclipse Diagram : r/flatearth

Discover the Mysterious Penumbra: The Almost Shadow

Mrs. Flynt's Wiki Page / umbra

Shadow Science – Types of Shadows

a: A side view of a receiving plane of non-constant z in lightspace