A heart attack, or myocardial infarction, happens when oxygen-rich blood does not reach a part of the heart muscle.
Around 8,000 years ago, Middle Eastern hunters carved to-scale plans of their 'desert kite' traps onto rocks.
Archaeologists in Switzerland have unearthed the remains of a fourth century A.D. watchtower built to protect the edge of the Roman Empire.
A new analysis of a comet in the asteroid belt reveals frozen water from the early solar system, hinting at the origins of water on Earth.