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TECH SPACE HUMAN EARTH HISTORY ANIMALS ADVENTURE VIDEO View Online How Heat Kills A combination of hot temperatures, high humidity and preexisting health conditions can make heat dangerous. READ MORE Pluto's Atmosphere Swept Back Like a Comet's Tail NASA's New Horizons mission confirmed that Pluto's atmosphere has  a "cavity" in the solar wind, revealing a long plasma tail reminiscent of a comet's ion tail. READ MORE WATCH VIDEO: Top Space Events For 2015 We're going to zoom through the Kuiper Belt and maybe even see black holes in detail. Hitchhiking Robot Embarks on U.S. Vacation Canada's hitchBOT heads south, traveling from Boston to San Francisco. Hopefully. READ MORE WATCH VIDEO: Can We Fall In Love With Robots? Find out what happens when human emotion and machines mix. Does Water Ever Expire? How come that glass of water you left out overnight tasted terrible by the next day? It's just water, right? Does it go bad?. WATCH Follow Discovery News on Facebook! Get your sci-tech headlines all day on Twitter too! At Discovery Communications, we value your privacy. If you would like to be removed from future communications like this, please click here. Privacy Policy Discovery Communications, LLC One Discovery Place Silver Spring, MD 20910 © Copyright 2015 Discovery Communications, LLC