A new analysis of x-rays streaming from the bright center of a galaxy has strengthened the case that a supermassive black hole lurks there. The x-rays imply that their source, a spinning disk of gas, surrounds an object with a density only a black hole could reach.
The man who masterminded the Soviet Union's early triumphs in military and civilian rocketry was born today in 1906. Sergei Korolyov launched his first liquid-fueled rocket in 1933 and helped develop the world's first two-stage rocket in the 1940s.
Researchers have developed a candidate vaccine against Ebola, one of the world's deadliest viruses. The vaccine, reported in January's Nature Medicine, has so far been tested only in mice and guinea pigs.
A link between Alzheimer's disease and mutations in mitochondrial DNA (mtDNA) arose from a flawed lab procedure, according to two reports in the current Proceedings of the National Academy of Sciences (PNAS).