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.
Eclipses can only occur when the Sun, Earth, and Moon are all in a straight line (termed syzygy). Solar eclipses occur at new moon, when the Moon is between the Sun and Earth. In contrast, lunar eclipses occur at full moon, when Earth is between the Sun and Moon.