Scientists have a pretty good idea what man-made greenhouse gasses are doing in our upper atmosphere, but not all of humanity's emissions stay up there. A good deal of that gas floats back down to Earth, seeping into the world's oceans and being absorbed by soil and plants on land. We're all familiar with this process, but NASA is looking for specifics: where on Earth, exactly, is this gas going, and why haven't we seen an increase in forestation to keep pace with our increased carbon emissions? That's what NASA's Jet Propulsion Laboratory hopes to find out. Tomorrow, it's launching Orbiting Carbon Observatory-2 -- a satellite built specifically to keep an eye on how carbon dioxide is distributed across the globe.