Isotopic analyses of meteorites reveal that the early Solar System contained several short-lived radionuclides (SLRs) with half lives ≤ 10 Myr. These SLRs are now all decayed and their presence in the Solar System at its birth remains a longstanding mystery. In this thesis, we propose that the Solar System received its SLRs from an injection of dust, formed from ejecta produced by a nearby supernova, into its already formed protoplanetary disk. This injection model, dubbed the "aerogel" model, for the origin of the Solar System's SLRs is tested here by comparing the results of theoretical modeling and numerical simulations to astronomical and meteoritic observations. Following a review of the evidence for the presence of SLRs at the time of the formation of the solar system and a description of the competing theories attempting to explain the origins of SLRs (inheritance, irradiation, and injection), the survivability of a disk hit with fast moving ejecta is tested via computer simulations, using an explicit two-dimensional finite-difference hydrodynamic code written for this purpose. It is found that a disk as close as 0.1 pc from the supernova will survive a collision with 2000 km/s ejecta, experiencing only a 1% mass loss in the process. To test the aerogel model further, the injection efficiency of supernova dust is computed in the following manner. Dust grains are added as tracers responding to snapshots of the gas velocity fields computed in the hydrodynamic simulations; the trajectories of these grains are followed as they make their way toward the disk. It is found that the majority (> 90%) of the supernova dust mass is injected deep into the disk. Finally, it is shown that a single supernova injects sufficient mass to explain the SLR abundances measured in meteorites. Predictions based on simulated supernova yields are within 10% of measured SLR ratios in meteorites.

In addition, predictions of other possible SLR ratios are calculated, suggesting non-negligible quantities of selenium-79 and tin-126 could be found in the meteoritic record. Their detection, however, could be difficult due to petrological considerations and the limitations of the instruments used to detect the remnants of extinct SLRs. Other possible evidence for the aerogel model may come from meteoritic record. Rough calculations show that ∼ 10% of supernova presolar grains found in meteorites should come from the single supernova that provided the solar system with its SLRs. The high abundance of low-density graphite grains that originate from a supernova compared to other presolar graphites suggest in particular they could come from the nearby supernova. Injection of supernova ejecta into a nearby already formed disk, the aerogel model, is entirely consistent with current meteoritical observations.