NASA is canceling a planned satellite that was going to intensely monitor greenhouse gases over the Americas because it got too costly and complicated. But the space agency said it will still be watching human-caused carbon pollution but in different ways. NASA on Tuesday announced that its GeoCarb mission, which was supposed to be a low-cost satellite to monitor carbon dioxide, methane and how plant life changes over North and South America, was being killed because of cost overruns. When it was announced six years ago, it was supposed to cost $166 million, but the latest NASA figures show costs...