Galileo started this quest over 400 years ago, and scientists finally were able to peek at one of the biggest mysteries of ...

1916: First day of the Battle of the Somme: the British Army suffers its worst day, losing 19,240 men. 1920: French tennis superstar Suzanne Lenglen beats Dorothea Chambers 6-3, 6-0 to win the ...

In the stratosphere over Siberia, temperatures recently jumped nearly 100 degrees Fahrenheit, shoving the polar vortex off its North Pole perch.

Mercury moves super fast around the Sun, finishing its year in just 88 Earth days. The planet has crazy temperature swings, ...