Mythology
Related to Sailor  Moon
The information in the following descriptions comes from a composite of both Greek and Roman mythology, but the Greek parts are used more often.  Much of my information comes from Bergen Evans' Dictionary of Mythology.
 

Luna, Artemis, Diana, Princess Serenity, and Endymion
There are several mythological references to the moon.  Of course, there are the three cats (two in the North American version so far) who are named after goddesses of the moon.  And, the names Princess Serenity (Princess Serena) and Endymion (Prince Darien) have origins in mythology as well.

 

The following names are the Greek version, unless otherwise noted.
 

Artemis (Roman: Diana)
 

Artemis was a daughter of Zeus and Leto, and the twin sister of Apollo.     She was a virgin, and was the goddess of the hunt, chastity, and     fertility (she was also connected to childbirth), and had the power of     inflicting or healing sickness.  As a goddess of birth, she became     connected with the lunar cycle, and was thus a moon goddess.  She was     represented in a tucked-up gown with a bow and a quiver of arrows.
 

Selene (Roman: Luna)
 

Selene was the Greek goddess of the moon.  In quite a few ways, she     was like the Roman Diana, but there were a few differences (for     instance Diana was a huntress and a virgin, Selene was neither).  Some     stories say that she had fifty daughters by Endymion.
 

Endymion
 

Endymion was a beautiful mortal man, a sheperd on Mount Latmos.  He was     loved by the moon (Selene).  He laid in eternal sleep, and there are     two guesses as to why:  1) Zeus put him to sleep so that he may remain     forever young, 2) Selene put him to sleep so that she could visit him     in full quiet.  Supposedly, he had fifty daughters with Selene.
 

It can be seen that the names Selene and Endymion were used because of the fact that they were a couple, and that Selene was related to the moon.  In Japanese, the "r" and "l" can be interchanged, creating the word "serene". From "serene", the name "Serenity" or the name "Serena" is formed.  The names Endymion and Darien probably have nothing in common though.
 

The Planets
The nine planets, with the exception of the Earth, are named after figures in Roman mythology.  Their equivalent Greek (and other) names are in parentheses.

 


Mercury (Greek: Hermes)
 

The prematurely born son of Zeus and Maia (Maia was a fertility      goddess; one of seven Pleaids/Pleaides, a group of nymphs that were      changed into a constellstion).  He seemed to be a very intelligent      baby; by noon of the day of his birth, he left his cradle, and invented      the lyre, building it from the shell of a tortoise.  Hermes was the      god of good luck, wealth, commerce, sleep, and dreams.  He was a      patron of merchants, thieves, and deception, the messenger and herald     of the gods, and the conductor of the souls of the dead to Hades.  He     appeared as a young man, wearing a broad-brimmed hat and winged sandals,     holding the caduceus (Hermes' staff, which was the symbol of the art of     medicine).
 

Venus (Greek: Aphrodite, Phoenician: Astarte)
 

Aphrodite was the child of Zeus and a Titan, who emerged from     the sea-foam at birth (in some accounts, Aphrodite simply emerges from     the foam), and is sometimes called the "Foam Born".  She was the goddess     of love, charm, beauty, and the impulses that bind men together in     social communion.  The Roman Aphrodite was more directly sexual than her     Greek equivalent.  In addition, the Phonecian Astarte was the goddess of     fecundity (baby producing).  Astarte was associated with the moon, and     was often depicted standing in a crescent moon.  Aphrodite appeared as     the wife of Hephaestus, the mother of Eros, and the lover of Ares (Roman     Mars).
 

Mars (Greek: Ares)
 

Ares was the son of Zeus and Hera. In Roman myths, Mars was one of the     cheif gods of the panthenon, as well as the god of war, exalting with     military power and glory (of course, Rome was one of the great military     empires).  However, the Greek Ares was a ferocious, brutal, blustering,     and cowardly god of war.  He was hated by all of the gods and goddesses,     with the exception of Aphrodite and her sister, Eris (goddess of     discord).
 

Jupiter (also Jove, Greek: Zeus)


Zeus was the son of the Titans Cronus and Rhea.  At the age of maturity,     he overthrew his father, and established the rule of the Olympian gods.     Zeus was the supreme deity, the most powerful of the gods.  He was a     sky god, a god of rain (Roman: Jupiter Pluvius), and the god of thunder     and thunderbolt (Roman: Jupiter Lapis).  Zeus was a promiscuous god, and     took many women, including her sisters and some mortal women.  He had     several sons and daughters.
 

Saturn (Greek: Cronus/Cronos/Kronos)
 

The Roman king-god Saturn was a god of the harvest.  He begot the major     Roman gods.  "Saturday" was named after him, as well as the planet     Saturn.  The Greek Cronus, on the other hand, was the mightiest Titan     of them all.  He ruled over all the Titans, and begot six children:     the Olympians.  Cronus was overthrown by his sixth child, Zeus.
 

Neptune (Greek: Poseidon)
 

Neptune was the Roman god of water, rain, and fertility.  In many     stories, he is referred to as the King of the Sea (or Ocean, or other     variants).  The Greek Poseidon was originally the god of earthquakes     and water, but that changed to the supreme god of the sea, and sometimes     the god of horses.  He was said to be tempestuous, violent, and     vindictive; he was rarely peaceful.
 

Uranus
 

In Roman Mythology, Uranus was the sky.  He was the son and husband of     Gaea (the earth).  With Gaea, he fathered the Titans, the Cyclops, the     hundred-handed monsters, and other creatures.
 

Pluto (also Dis/Orcus, Greek: Hades)
 

Hades was the lord of the Underworld.  He was a gloomy, stern, and dull     god.  He was also connected to Plutus, a being who personifies wealth.     Little is known about this particular god, other than his abduction     of Persephone (Roman: Proserpina).  "Hades" is also a name for the     Underworld.