A strange swirl in the sky seen over much of Britain and Europe this week wasn’t the result of alien activity but rather a ...

The Oort cloud is traditionally thought of as a vast shell of perhaps trillions of icy objects encasing our solar system, serving as the final boundary between us and the dark reaches of ...

Typically, they have a spiral-shaped shell into which they retract when they perceive danger. While this shell is one of their most characteristic features, slugs lacking shells belong in the same ...