☽ Moon

Called Luna by the Romans and Selene by the Greeks

Night Moonlight

Which sign is the Moon in now?

Detail of Partial Eclipse of the Moon by Étienne Léopold Trouvelot
Partial Eclipse of the Moon Étienne Léopold Trouvelot, 1874 New York Public Library The partial lunar eclipse he watched on October 24, 1874, with Earth’s shadow over part of the Moon. Plate VII of The Trouvelot Astronomical Drawings. Public domain, via Wikimedia Commons

Earth’s only natural satellite, which the Romans called Luna and the Greeks Selene, the goddess who drove her chariot across the night sky.

In myth

In the Homeric Hymn to Selene, the Moon is a goddess whose radiance, shining from her immortal head, embraces the earth. She bathes in the waters of Ocean, puts on her gleaming robes and drives her long-maned horses at full speed in the evening at mid-month, when her orbit is full and her light is brightest. Zeus loved her, and she bore him a daughter, Pandia. Hesiod makes her the daughter of the Titans Hyperion and Theia and the sister of Helios and Eos. In Rome, Luna had a temple on the Aventine Hill, and Monday, dies Lunae, was named for her.

Goddesses of the Moon

In the Goddess Encyclopedia, these goddesses count the Moon among their realms:

Artemis Selene Hecate Diana Luna Chang'e Ixchel Coyolxāuhqui Mama Killa Hina

How the moon got its name

NASA explains that our satellite is simply called the Moon because people didn’t know other moons existed until Galileo Galilei discovered four moons orbiting Jupiter in 1610. In Latin it was Luna, which gives us the adjective “lunar.”

Symbols

Chariot and horses Crescent moon Gleaming robes

The moon

The Moon turns on its axis in the same time it takes to go around Earth, so the same side always faces us. It likely formed after a Mars-sized body collided with Earth several billion years ago. Its dark patches, the maria, are impact basins that filled with lava between 4.2 and 1.2 billion years ago. The Moon is getting about an inch farther from Earth each year, and Apollo astronauts brought back 382 kg of its rocks and soil.

Diameter
3,475 km 0.27 × Earth
Mass
0.0735 × 10²⁴ kg 1.2% of Earth’s
Gravity
1.62 m/s² 0.165 × Earth's, about a sixth
Distance from Earth
384,400 km 363,300 to 405,500 km, nearest to farthest
Once around Earth
27.3 days measured against the stars
New moon to new moon
29.5 days the month of phases
Spins once in
27.3 days so the same side always faces Earth
Surface temperature
127 °C in sunlight about −173 °C in darkness

Figures from NASA’s Moon Fact Sheet; the surface temperatures are from NASA’s Moon facts page. Comparisons with Earth are from the fact sheet.

Learn more