Veteran astronaut Michael Fincke's sudden medical emergency aboard the ISS is a stark reminder that, as NASA pushes toward long-term lunar missions, astronaut health remains one of spaceflight's biggest unknowns.

A new species of dinosaur that was probably a princely ancestor of T. rex, the king of the dinosaurs, has been identified from fossils excavated in Mongolia.

Scientists say they have very strong evidence that the adult human brain is capable of making new neurons, a point of ongoing controversy in neuroscience.