For other uses of the word "umbra", see Umbra (disambiguation). The umbra is the darkest part of a shadow. ...

For other uses of the word "penumbra", see Penumbra (disambiguation). Look up penumbra in Wiktionary, the free dictionary. ...

Umbra, penumbra and antumbra.

Earth's shadow, to scale, showing the extent of the umbral cone beyond the Moon's orbit (yellow dot, also to scale).

The umbra, penumbra and antumbra are the names given to the three distinct parts of a shadow which are created when the source of light is not a point source. In reality there is no such thing as a point source radiator, though in theory such a light source would cast an umbra and antumbra, but not a penumbra. Shadows on pavement A shadow is a region of darkness where light is blocked. ... Look up point source in Wiktionary, the free dictionary. ... This box:      Electromagnetic (EM) radiation is a self-propagating wave in space with electric and magnetic components. ...

The umbra (Latin: shadow) is the darkest part of a shadow. From within the umbra, the source of light is completely concealed by the occulting body. In astronomy, an observer in the umbra is said to be experiencing an total eclipse. Shadows on pavement A shadow is a region of darkness where light is blocked. ... For other uses, see Light (disambiguation). ... In this July, 1997 still frame captured from video, the bright star Aldebaran has just reappeared on the dark limb of the waning crescent moon in this predawn occultation. ... For other uses, see Astronomy (disambiguation). ... For the 1995 film, see Total Eclipse (film). ...

The penumbra (Latin: paenes "almost, nearly" + umbra "shadow"), where the light source is only partially concealed. More specifically, the penumbra is the region in which only a portion of the occulting body is obscuring the light source. An observer in the penumbra experiences a partial eclipse.

The antumbra is similar to the penumbra, the main point of contrast being that the occulting body is entirely contained within the disc of the light source. If the observer moved closer to the light source, the apparent size of the occulting body would increase until it causes a full umbra. An observer in this region is experiencing an annular eclipse. For Solar Eclipse, the alien friend of the rubber doll Betty Spaghetty, see Betty Spaghetty Photo taken by John Walker during the Zambia 2001 eclipse A solar eclipse occurs when the Sun, Moon and Earth are on a single line with the Moon in the middle. ...

References

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