The paper presents a thought experiment as to the feasibility of using large scale wireless sensor networks as a vehicle for high level scientific investigation. The discussion is framed by a demanding scenario, that of planetary exploration, and the assessment of feasibility is driven by the available micromachining technologies and recent advances in the areas of ad-hoc networking, communications and intelligent sensing. Following discussion on the development of the mission, the next question addressed is if and how MEMS and VLSI technologies could be integrated to provide a self-contained space probe, 40mm in length. A sensor payload is proposed, which includes means of seismic, chemical, temperature and visual exploration. The power and communications systems are also discussed, based on the needs of a mission profile which provides no special 'base station' nodes on the planet's surface, requiring each sensor package to be capable of information extraction, in-network collaboration and communication with an orbiting satellite. The outcome of the thought experiment described is a positive assertion of feasibility for the sensor node hardware, given current levels of MEMS and VLSI technologies. With respect to the wireless ad-hoc networking aspects of the proposed deployment, pointers are given to the issues which are still necessitating research work, mainly from the computer sciences community.