For decades, scientists have puzzled over why Earth stayed warm and alive while Mars turned cold and dry. Both planets began with similar ingredients—rocky surfaces, carbon, water, and sunlight—but ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth ...

Analysis by researchers at the University of Bern suggests that water and other volatile compounds arrived on Earth from outer space—specifically via a collision with a Mars-sized planet billions of ...

The key to determining which planets could host extraterrestrial life could be growing in the harshest deserts of Earth in the form of lichen. The secret to this discovery: the "world's best sunscreen ...