Deimos is a Greek word that means dread or terror. It appears in classical mythology as a personified force that accompanies the god of war into battle, and it also names the smaller of Mars’s two moons. Because of those roots, the term often evokes fear, panic, or the ominous atmosphere around war.

In Greek Mythology

Deimos is the son of Ares and Aphrodite and the twin or close companion of Phobos, whose name means fear. Ancient poets used Deimos to describe the chilling dread that spreads through an army, while Phobos captured the immediate fear of flight. Together they symbolized the psychological dimension of warfare.

As a Moon of Mars

Astronomers gave Mars’s two moons mythic names that fit the warlike theme of the planet. Deimos is the smaller and more distant one. Key facts that help place it:

• Shape and size: irregular, roughly 12 kilometers across at its widest
• Surface: dark, heavily cratered, covered in regolith
• Orbit: circles Mars in about 30 hours at a distance of roughly 23,500 kilometers
• Origin theories: captured asteroid or rubble that coalesced from debris around Mars

Because it is small and dark, Deimos is hard to study in detail, yet it remains important for understanding the history of Mars and small bodies in our solar system.

Language and Etymology

The Greek δειμός (deimos) translates to dread, terror, or fearful awe. In English usage, “Deimos” retains the capitalized proper noun form when referring to the mythic figure or the Martian moon. The lowercase sense is rare and mainly rhetorical.

Modern Cultural Uses

Writers, game designers, and bands use “Deimos” when they want a name that suggests menace, cosmic mystery, or the psychological edge of fear. You may see it in titles, levels, or character names that aim for a dark or martial mood.

Pronunciation

Most English speakers say DEE-moss or DEE-mohs. In reconstructed classical Greek, it would be closer to DAY-moss.

Deimos vs. Phobos

• Deimos: dread or terror at a scale that chills resolve
• Phobos: fear that triggers flight or panic
• In space: Deimos is smaller and farther from Mars; Phobos is larger and orbits closer and faster

Quick Answers

• What does Deimos mean? Dread or terror.
• Who is Deimos in myth? A personification of dread, companion of Ares, sibling of Phobos.
• What is Deimos in astronomy? The smaller, outer moon of Mars.
• Why use the name? It signals themes of fear, war, or ominous tension, and ties to Mars.