second moon
Definition
An informal term for a quasi-moon or temporary mini-moon of Earth, referring to asteroids like 2024 PT5 or 2025 PN7 that follow a horseshoe-shaped orbit around the Earth-Sun system, temporarily behaving like a second natural satellite.
Any secondary natural or quasi-natural satellite of a planet, beyond its primary moon, often discussed in astronomy for objects like Earth's asteroid 3753 Cruithne.
Examples
Forget the man in the moon – astronomers are buzzing about Earth's second moon, a sneaky asteroid that's crashing the party for a few years.
If our second moon sticks around, midnight picnics might come with double the glow and twice the werewolf complaints.
NASA's latest quasi-moon is like that friend who shows up uninvited to your orbit and overstays for decades.
Tide charts went haywire when the second moon joined the gravitational mosh pit around Earth.