Extraterrestrial liquid water Extraterrestrial liquid water Extraterrestrial liquid water (from the Latin words: "extra" ["outside of, beyond"] and "terrestris" ["of or belonging to Earth"]) is water in its liquid state that naturally occurs outside Earth. It is a subject of wide interest because it is recognized as one of the key prerequisites for life as we know it and thus surmised as essential for extraterrestrial life. With oceanic water covering 71% of its surface, Earth is the only planet known to have stable bodies of liquid water on its surface, and liquid water is essential to all known life forms on Earth. The
Solid waste policy in the United States to more than 33%. The most recent numbers from the EPA indicate that in 2012 the US municipal solid waste recycle rate was 34.5%. This section describes the common methods of solid waste disposal practiced in United States and worldwide. Some of the main issues associated with waste are open dumping, odor, particulate matter emissions, leachate seepage from landfills, greenhouse gas (GHG) emissions that lead to air pollution, surface and groundwater pollution, food chain contamination, land area depletion, human health impacts, environmental degradation, and negative impacts on plant and animal life. All levels of government - federal, state, and local