Hypothesis: The Retrograde Debris Complex (3I/ATLAS, Niku, Drac) as the Kinematic Signature of "Planet Nine"

Abstract: Current astronomical research has proposed multiple hypothetical bodies to explain anomalies in the outer solar system, including "Planet Nine," "Planet X," and "Planet Y." However, these models rely heavily on the clustering of prograde Trans-Neptunian Objects (TNOs). This paper proposes a complementary line of evidence: the existence of a distinct "Retrograde Debris Complex" comprising high-inclination objects such as 2011 KT19 ("Niku"), 2008 KV42 ("Drac"), 2015 BZ509, and the interstellar object 3I/ATLAS. While current science treats these bodies as unrelated anomalies, we argue that their kinematic similarities suggest a common origin. By analyzing the "anti-tail" morphology of 3I/ATLAS and the orbital clustering of the Niku-Drac group, we present the "Shrapnel Hypothesis": that these objects represent the collisional debris field of a massive body orbiting in a retrograde plane. Finally, adhering to the philological arguments for descriptive nomenclature (Iorio, 2025), we propose the name "Ketu" for this hypothetical perturber. Derived from the Sanskrit astronomical tradition, "Ketu" denotes the "descending node" and is characterized by retrograde motion and cometary "tails," offering a culturally and scientifically accurate descriptor for a massive body that governs a retrograde debris field.

Plain Language Summary (SEO): This paper explores the theory that the hypothetical "Planet Nine" is actually a massive object orbiting in a retrograde (backwards) direction, which we propose naming "Planet Ketu." We present forensic evidence linking several "impossible" objects—including the interstellar comet 3I/ATLAS and the TNOs Niku and Drac—suggesting they are not random visitors, but shrapnel from a collision caused by this planet. Specifically, the anomalous "anti-tail" of 3I/ATLAS indicates it is heavy, rocky debris, consistent with a high-speed retrograde impact. This hypothesis offers a unified explanation for the vertical and retrograde anomalies in the outer solar system.