The Lunar Occultation Explorer (LOX) is a paradigm shift - a next-generation mission concept that will provide new capabilities in time-domain astrophysics and established the Moon as a platform for nuclear astrophysics. Currently under review by NASA’s Explorer Program, LOX's performance requirements are driven by focused science goals designed to resolve the enigma of Type-Ia supernova (SNeIa) and their role in galactic evolution and cosmology. The proposed investigations will reveal details of these profoundly radioactive objects using long-term (>100 day) monitoring of the emergent nuclear gamma-ray spectra and their corresponding light curves. Primary science objectives include, but are not limited to, probing the fundamental thermonuclear physics processes, performing a census of progenitors and their explosion mechanisms, and evaluating the environmental conditions and intrinsic systematics of these enigmatic objects. LOX provides new capabilities for all-sky, continuous monitoring in the MeV regime (0.1-10 MeV) by leveraging the Lunar Occultation Technique (LOT). Key benefits of the LOX/LOT approach include maximizing the ratio of sensitive-to-total deployed mass, low implementation risk, and demonstrated operational simplicity that leverages extensive experience with planetary orbital geochemistry investigations. LOX will also deliver a time-domain survey of the nuclear cosmos. Proof-of-principle efforts have validated all aspects of the mission using previously deployed lunar science assets, including the first high-energy gamma-ray source detected at the Moon. LOX mission design, performance, and science will be presented.