Three Theories About Where the Nickel Comes From
Scientists have three main ideas about what’s happening:
Theory 1: Metal carbonyl molecules. These are chemicals where metal atoms bond with carbon monoxide, like nickel tetracarbonyl. They’re extremely unstable—so unstable they’re used in industrial processes precisely because they fall apart easily. If these molecules exist on the 3I/ATLAS, sunlight would shatter them almost immediately, releasing nickel atoms right near the surface.
Theory 2: Metals stuck to tar-like molecules. Polycyclic aromatic hydrocarbons (PAHs) are complex carbon-based molecules—think of them as cosmic tar or soot. Nickel atoms might be attached to these molecules. When ultraviolet light from the Sun hits them, the nickel breaks free.
Theory 3: Chemical reactions happening in real-time. The dust from 3I/ATLAS might contain nickel sulfide minerals (minerals where nickel and sulfur bond together). When these encounter carbon monoxide gas also streaming off the object, they could react to form nickel carbonyls right there in space, which then immediately break apart.
Each theory points to different conditions in whatever alien star system birthed this comet billions of years ago.
