(AOL) — Researchers have discovered some space junk hurtling toward Earth, and they aren’t exactly sure what it is.

The oh-so-appropriately titled WT1190F is expected to hit Earth Nov. 13 — or “WTF” for short. It’s likely a piece of debris left by man from a previous space mission, maybe even one of the Apollo missions. But since scientists don’t know technically what it is, that means it’s a UFO.

Important reminder: A UFO is any unidentified flying object, not just one of suspected alien or supernatural origins.

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