A spider-like scar haunts Jupiter's moon Europa — and scientists think they know why

A strange, spider-like scar on Jupiter's icy moon Europa may mark where salty water once surged up through its fractured crust.

NASA's Galileo spacecraft (whose mission ended in 2003) spotted the unique feature — officially named Damhán Alla, an Irish word meaning "spider" or "wall demon" — within Europa's Manannán crater. The starburst-like pattern first appeared in images captured by the spacecraft in the late 1990s, but scientists are only now piecing together how it may have formed, according to a statement from Trinity College Dublin.

The spider-like features exhibit branching ridges and troughs that resemble "lake stars" on Earth — delicate, dendritic patterns carved into snow and ice by flowing meltwater. This resemblance, combined with field observations, lab experiments and comp