There are 8 billion of us alive today, give or take a few hundred million. We crowd cities, cross oceans in mere hours, and ...

Landing humans on Mars could teach us whether life ever existed beyond Earth, how planets change over time, and how humans can live on other worlds. By studying Mars up close, astronauts could answer ...

James is a published author with multiple pop-history and science books to his name. He specializes in history, space, strange science, and anything out of the ordinary.View full profile James is a ...

"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." “We were surprised to find that the actual population living in rural areas is much higher than the ...

The ideal number of humans on Earth is around 2.5 billion and a major study explains what that means for our future.