With the recognition of an increasing potential for discovery of extraterrestrial life, a diverse set of researchers have noted a need to examine the foundational ethical principles that should frame our collective space activities as we explore outer space. A COSPAR Workshop on Ethical Considerations for Planetary Protection in Space Exploration was convened at Princeton University on June 8-10, 2010, to examine whether planetary protection measures and practices should be extended to protect planetary environments within an ethical framework that goes beyond "science protection" per se. The workshop had been in development prior to a 2006 NRC report on preventing the forward contamination of Mars, although it responded directly to one of the recommendations of that report and to several peer-reviewed papers as well. The workshop focused on the implications and responsibilities engendered when exploring outer space while avoiding harmful impacts on planetary bodies. Over 3 days, workshop participants developed a set of recommendations addressing the need for a revised policy framework to address "harmful contamination" beyond biological contamination, noting that it is important to maintain the current COSPAR planetary protection policy for scientific exploration and activities. The attendees agreed that there is need for further study of the ethical considerations used on Earth and the examination of management options and governmental mechanisms useful for establishing an environmental stewardship framework that incorporates both scientific input and enforcement. Scientists need to undertake public dialogue to communicate widely about these future policy deliberations and to ensure public involvement in decision making. A number of incremental steps have been taken since the workshop to implement some of these recommendations.