Active beacon transmissions from Earth, partial inventory: (a) 1962 Morse code transmission, Yevpatoria, target Venus; (b) Arecibo Message, 1974-11-16, target M13, 23 km/s through interstellar medium, ETA 25,000 years; (c) Voyager Golden Record, departing heliopause 2012-08-25, content curated by Carl Sagan; (d) Cosmic Call 1, 1999, four target stars; (e) Cosmic Call 2, 2003, expanded target list; (f) Lone Signal, 2013, public-uploaded messages targeted at Gliese 526; (g) METI International, 2017-10-16, EISCAT Tromsø, target Luyten's Star (12.4 ly), 33-minute mathematical and musical payload.

Receiving infrastructure (passive SETI): Project Ozma (1960, Frank Drake, Green Bank). Big Ear Radio Observatory (Wow! Signal, 1977-08-15). Arecibo (operations 1963-2020, collapse 2020-12-01). Allen Telescope Array. Breakthrough Listen (2015-, Yuri Milner endowment). FAST 500m, China 2016-. Result across 65 years of dedicated listening: zero confirmed extraterrestrial signal detection.

October 2025: 3I/ATLAS, third confirmed interstellar object, identified by ATLAS survey. Trajectory hyperbolic; spectral signature consistent with comet outgassing; closest approach Sun 2025-10-29 at 1.36 AU. Fragment Zero notes: regardless of 3I/ATLAS identity (natural object vs probe), its passage was detectable by Earth-based instruments at decade-prior advance notice. The asymmetry — that Earth could detect 3I/ATLAS approaching — is mathematically symmetric: any sufficiently advanced observer could detect Earth-origin transmissions at corresponding decade-prior intervals along their light-cone path.

Part 2 of this casefile (publication scheduled +7 days under Fragment Zero multi-part release cadence) addresses the silence camp: arguments by Stephen Hawking, the SETI Institute principal scientists, and the changes in active-broadcast policy that emerged in 2025. The case file does not close.