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 ... suggests that the spiral structure has been here almost since our system's beginning, retaining its shape all the while.

Typically, they have a spiral-shaped shell into which they retract when they perceive danger. While this shell is one of ...

Ammonites' growing shells typically formed into a flat spiral, known as a planispiral, although a variety of shapes did evolve over time. Shells could be a loose spiral or tightly curled with whorls ...