He took images of a roughly one-inch-wide, quarter-inch-deep dish of water vibrated ... back and forth. Where waves meet and add up, they create nodes. When ripples cancel out, troughs appear.

Here’s how it works. Gravitational waves are tiny ripples in the very fabric of spacetime that propagate outwards from some of the most violent and powerful events in the cosmos. Traveling ...

Planetary geologists and astronomers studying Mars have known for decades that water was once likely present on the planet, after NASA's Mariner 9 mission captured images of dry gullies in the 1970s.