Impacter

Impacter is a relatively uncommon spelling of impactor, a term used in various fields to denote an object that causes or experiences an impact. In most technical writing, impactor is the preferred form; impacter is typically a misspelling or a rarely used variant.

In planetary science, an impactor is the natural or artificial body that collides with a planet, moon, or spacecraft. Examples include meteoroids, asteroids, and comets that strike a planetary surface, as well as engineered spacecraft designed to collide for research purposes. Notable missions have used impactors to study surface composition, crater formation, and other impact processes, such as the Deep Impact mission which deployed an impactor to collide with comet Tempel 1.

In engineering and materials testing, an impacter can refer to a component that delivers an impact force, such as a hammer or striker in an impact testing apparatus. The term highlights the role of delivering a controlled impact to assess material response, durability, or energy transfer.

Etymology and usage notes: impacter originates from impact plus the agent noun suffix -er, mirroring impactor. While both forms appear, impactor is overwhelmingly standard in scholarly and technical literature. Impacter is more common in general writing and non-technical contexts, where it may be encountered as an alternate spelling or error. See also impact and impact testing.