Earth & SkyGreek → English
Deimos
/ˈdaɪmɒs/noun
The smaller and outer of the two moons of Mars.
The Greek roots
δεῖμος
deîmos
dread, terror
Literally: “dread”
Follow a root:δεῖμος1 word
The story of the word
Asaph Hall found it on 12 August 1877, six days before its larger companion, and the pair were named for the two attendants who yoke the war god's horses in the fifteenth book of the Iliad. Deimos is about twelve kilometres across, dark, and so far out that from the Martian surface it looks like a slow bright star rather than a moon. Its root is the fear word behind δεινός, terrible, which is the first half of dinosaur.
- How it travelled
- Ancient Greek → astronomical naming → English
- First recorded
- 1877
Same family
dinosaurdeinonychus
In a sentence
Deimos takes about thirty hours to circle Mars, so it drifts across the sky for days at a time.