First Impact (aka "Giant Impact") was the collision of a giant spherical object, designated the "Black Moon", into Earth approximately 4 billion years ago. As a result of the impact, huge amounts of debris, including the Black Moon's rocky exterior, were thrown into orbit, eventually coalescing into Earth's satellite, the Moon. The core of the Black Moon, and the Seed of Life Lilith contained within it, remained intact, although Lilith's Spear of Longinus was somehow lost or destroyed during the collision.
The First Impact cover story released to the public contends that a huge meteorite was responsible, rather than the Black Moon. Although originally referred to as "Giant Impact", this event was retroactively dubbed "First Impact", as opposed to the later "Second Impact" (which the public was similarly misled to believe was caused by a massive meteorite).
- The real-life Giant Impact Theory states that during the early formation of the solar system, a Mars-sized planetoid named "Theia" collided with proto-Earth as it was still forming. The ejected material from the collision coalesced due to gravity, and was caught in Earth's orbit, becoming the Moon.
- A recurring visual motif throughout the series pairs Rei Ayanami with the Moon. Rei's body is a "vessel" for the soul of Lilith, so, in a sense, she actually created the Moon.
- This connection is also referenced via the craters on Lilith's mask.
- First Impact was never depicted or directly referred to on-screen. This has led several fans upon first glance to incorrectly assume that because the "Second Impact" was supposedly a meteorite collision, the "First Impact" was thus the more well known asteroid impact which caused the mass-extinction of the dinosaurs at the end of the Cretaceous period, 65 million years ago.