The Rosetta orbiter, currently studying comet 67P/Churyumov-Gerasimenko as it orbits the Sun, has been watching how the comet has changed as it moves toward its perihelion (point of closest approach to the Sun) in August of 2015.  As the comet heats up from the increasing intensity of the Sun’s rays, it releases surface gases and dust into what eventually becomes the atmosphere-like coma surrounding the comet.  As the comet moves the material produces the visible tail that we usually associate with a comet.  With 67P specifically, Rosetta has recently made a surprising discovery: That the water and carbon dioxide streaming...