Enlarge / The Nesjavellir Geothermal Power Station. Geothermal power has long been popular in volcanic countries like Iceland, where hot water bubbles from...
Enlarge / Computer illustration of mitochondria, membrane-enclosed cellular organelles that produce energy.KATERYNA KON/SCIENCE PHOTO LIBRARY/GETTY More than 1.5 billion years ago, a...
Enlarge / Spectral analysis indicates that silica is present in this supernova remnant, Cassiopeia A.NASA/JPL-Caltech/ O. Krause (Steward Observatory) Ever since neutron...