noun
near-Earth asteroid; NEA
Technical astronomy term for an asteroid whose orbit brings it close to Earth.
地球近傍小惑星の軌道を追跡することは、惑星防衛にとって重要だ。
Tracking the orbits of near-Earth asteroids is important for planetary defense.
Compound of 地球 (Earth) + 近傍 (neighborhood, vicinity) + 小惑星 (asteroid). A direct calque of the English term 'near-Earth asteroid'.