What does impactor mean?
An impactor is an object that collides with another object, normally with considerable force or speed. The word is especially common in astronomy and planetary science, where it can denote an asteroid, comet, or other body heading toward a planet or moon. Engineers also use it for devices or projectiles designed to test the resistance of structures by striking them. In these contexts, the word identifies the striking body rather than the collision itself: the impactor is the object that hits, while the impact is the event and its consequences. The term is more technical than the general words “object” or “thing,” so its appearance usually signals a scientific, engineering, or safety-testing discussion. Although rarely encountered in everyday speech, it is useful when distinguishing the cause of a collision from its effects.
nounAn object or body that strikes, collides with, or comes into contact with another body, especially at high speed. The term is used particularly in astronomy, planetary science, and impact-testing contexts.
- An object or body that collides with another body, especially a celestial object moving at high speed.
"Scientists tracked the asteroid impactor as it approached the planet's atmosphere."
"The impactor struck the moon and produced a crater visible from orbit."
"Engineers used the vehicle as a high-speed impactor to test the protective panels."
The plural is formed by adding the ending -s.
"Researchers modelled the trajectories of several possible impactors."
An impactor may travel for millions of kilometres, yet the moment it strikes, it can leave a crater that records its journey through deep time.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does impactor come from?
“Impactor” was formed in the 19th century from “impact” and the suffix “-or,” meaning an agent or instrument that performs an action. “Impact” in turn comes from Latin impingere, “to strike or dash against,” from in- and pangere, “to drive or strike.” The same Latin root underlies English words such as “impinge” and “impingement.”
How impactor is actually used
This is chiefly a technical term. In astronomy and planetary science, it normally refers to an asteroid, comet, or other celestial body that is expected to collide with a planet, moon, or spacecraft.
Easily confused with impactor
Impact is the event of one body colliding with another, whereas an impactor is the object that makes the collision.