As Costco devotees are well aware, employees never fail to check receipts at the door. In fact, since the chain’s opening in ...

Newly released images of Mars reveal a "smiley" salt deposit on the Red Planet's surface. A related study suggests that ...

Every fall, a smiley face made of trees appears on a hill in Polk County. It’s a happy sight for motorists driving along ...

Stunning new images from the ExoMars orbiter reveal ancient salt deposits on Mars, even forming a smiley face.