Mass tree die-offs are sparking worries of fire in California’s Sierra Nevada range. An outbreak of bark beetles, along with persistent drought in the state, have caused many evergreen trees to wither and die.The damage spread rapidly through the mountains in the fall of 2015 after favorable spring conditions (warm and dry) led to a…

This image from NASA's Dawn spacecraft shows Kupalo Crater, one of the youngest craters on Ceres. Image Credit: NASA/JPL Caltech/UCLA/MPS/DLR/IDAFeatures on dwarf planet Ceres that piqued the interest of scientists throughout 2015 stand out in exquisite detail in the latest images from NASA's Dawn spacecraft, which recently reached its lowest-ever altitude at Ceres.Dawn took these images…

Winter storms can blanket Iceland almost entirely with snow. The relative warmth of summer and fall, however, exposes a spectacular, varied landscape. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this natural-color view of the Nordic island nation on November 9, 2015.“The visible snow cover is typical for this time of the year, compared to conditions during…