Detriment and fall
Detriment is the sign opposite a planet's domicile and fall is the sign opposite its exaltation; both describe a planet working against the grain of the sign it occupies.
Mars in Libra has to negotiate where it would rather act; the Moon in Capricorn has to justify a feeling before having it. Nothing here is broken, and classical authors treat these placements as harder to run rather than as damaged.
Our reports name the tier and leave the reading to the sentence around it, because a debility describes the planet's condition and never the person.
Frequently asked
Is a planet in fall unlucky?
No. It describes a planet that has to work in an unfamiliar style, which often shows as effort rather than as misfortune.
Can a planet be in detriment and still strong?
Yes. Accidental conditions such as angularity, speed and support from other planets can carry a planet that is weak by sign.