Non-terrestrial networks (NTNs) offer promising solutions for extending connectivity to remote and underserved areas, but their potential for integrated sensing and communication (ISAC) remains underexplored, particularly in distributed configurations. We show that for distributed NTN systems, owing to their large virtual antenna apertures, Earth's surface falls within the near-field regime. Hence, it is possible to perform near-field beamfocusing with these systems. The possibility of beamfocusing opens the way for sensing and tracking large metallic objects, such as ships and aircraft. The approach is pragmatic as it repurposes existing RF communication hardware with minimal additional signal processing, eliminating the need for dedicated radar-specific equipment and providing a cost-effective alternative. To overcome the phase and gain impairments from the dynamic nature of the distributed NTN system, we also propose a Kalman filter-based framework to compensate for these impairments. Simulation results demonstrate significantly narrower 3 dB beamwidths (from tens of kilometers to tens of meters) and improved echo signal strength (by 20-50 dB) in distributed NTN systems compared to single-platform NTNs. The framework addresses practical challenges like platform synchronization and handover in dynamic environments, paving the way for resilient, dual-function NTN for the future.