When an observer is on the unlit side of Earth, they can witness different types of shadows and eclipses depending on the positions and alignments of the Sun, Earth, and other celestial bodies. Here are the types of shadows and eclipses that can be observed in different scenarios:
Shadows:
a. Umbra: The darkest part of a shadow where all light is blocked. This occurs during a total solar eclipse when the Moon completely blocks the Sun.
b. Penumbra: The lighter part of a shadow where only a portion of the light source is blocked. This occurs during a partial solar eclipse when the Moon partially blocks the Sun.
Eclipses:
a. Solar Eclipse:
i. Total Solar Eclipse: This occurs when the Moon passes directly between the Sun and Earth, completely blocking the Sun's disk. The observer on the unlit side of Earth will see a total solar eclipse with the Sun completely covered by the Moon.
ii. Partial Solar Eclipse: This occurs when the Moon partially covers the Sun's disk, but does not completely block it. The observer on the unlit side of Earth will see a partial solar eclipse with the Moon covering only a portion of the Sun.
b. Lunar Eclipse:
i. Total Lunar Eclipse: This occurs when the Earth is directly between the Sun and the Moon, and the Moon passes through Earth's shadow. The observer on the unlit side of Earth will see a total lunar eclipse with the Moon appearing reddish or copper-colored due to the scattering of sunlight by Earth's atmosphere.
ii. Partial Lunar Eclipse: This occurs when only a portion of the Moon passes through Earth's shadow. The observer on the unlit side of Earth will see a partial lunar eclipse with only a part of the Moon covered by Earth's shadow.
iii. Penumbral Lunar Eclipse: This occurs when the Moon passes through the outer part of Earth's shadow, known as the penumbra. The observer on the unlit side of Earth will see a penumbral lunar eclipse with the Moon appearing slightly darker but without a noticeable change in its brightness.
Please note that the occurrence and visibility of these phenomena may vary depending on the geographical location of the observer and the specific celestial alignments.