Codon Codon is a combination of three successive nucleotides in a DNA or RNA strand. All the nucleic acids, DNA and RNA, have nucleotides sequenced as a set of codons. Each nucleotide consists of a nitrogenous base, one of A, C, T/U, or G.
Phases of the moon are simply how much sun is hitting the surface of the moon, with the moon being between the earth and the sun. Lunar eclipses occur when a conjunction between the earth and the sun... with the earth casting a shadow on the full moon.
Â©2014 by Fred Espenak. Introduction. An eclipse of the Moon (or lunar eclipse) can only occur at Full Moon, and only if the Moon passes through some portion of the Earth's shadow. The shadow is actually composed of two cone-shaped components, one nested inside the other.