"You could pull up Google Earth images of places like Utah, zoom out, and you’d see the similarities to Mars." ...

New research suggests ancient Mars may have been warm and wet, with rainfall or snowmelt carving its iconic valleys.

Perhaps the best known of all comets is Halley, correctly pronounced so that it rhymes with rally, not daily. It is named after the 17th-18th century astronomer Edmond Halley. This ...