LPL Colloquium: Uncovering the "buried" planet that formed our Moon

Dr. Qian Yuan, O.K. Earl Postdoctoral Fellow, California Institute of Technology


3:45 to 4:45 p.m., Feb. 13, 2024


Abstract: Earth’s Moon is widely accepted to have been created 4.5 billion years ago through a giant impact between Earth and a hypothetical planet known as Theia. Yet, direct evidence for Theia's existence has remained elusive--until now. Here, we demonstrate that the mantle remnants of Theia explain fundamentally important features of the largest seismically-imaged anomalies within Earth – the two large low-shear-velocity provinces (LLSVPs) in Earth's deepest mantle. We combine state-of-art evidence from theoretical and computational astrophysics, geodynamics, mineral physics and seismology to demonstrate how Theia mantle remnants naturally provide an explanation for a compositionally distinct origin for LLSVPs, as well as their age, density and size. This study substantially expands the influence of giant-impact planetary processes in shaping Earth's evolution, with implications for comprehending the diversity of terrestrial planets and the quest for Earth-like exoplanets.

More information about Dr. Qian Yuan

Zoom guidelines and information

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For those viewing the colloquium in room 308, refreshments will be served in the Kuiper atrium at 3:30 p.m.

***Refreshments are not permitted in the seminar room.***



Bertha K. Orosco