King and her colleagues examined the rock, and, in a paper published Wednesday in Science Advances, they propose that similar meteorites may have delivered water to Earth during the solar system's youth. It is one of two new studies suggesting space rocks brought water and molecules key for the formation of life to a young Earth and Mars. The Winchcombe meteorite is a rare type of carbon-rich rock called a carbonaceous chondrite and the first of its kind ever found in the U.K. Only about 4 to 5 percent of all meteorites found on Earth belong to this group of rocks. Clocking in at billions of years old, they provide a glimpse into the solar system's early history, when they formed in the asteroid belt between Mars and Jupiter.