With Area 51 ruled out by President Obama, where might aliens really be hiding? Scientists have now revealed the best candidates.

An object from outside our solar system is behaving in ways scientists did not expect. As it approaches the inner system, its brightness, jets, and structure are changing unpredictably. This episode ...

A city-sized green comet, C/2024 E1 (Wierzchoś), is approaching Earth and will soon be ejected into interstellar space, offering astronomers a rare chance to study a hyperbolic visitor from the Oort ...

A team of astronomers has identified a four-planet system orbiting the red dwarf star LHS 1903 that defies conventional expectations about how planets arrange themselves around their host stars. The ...

A recent study showed that Mars was warm and wet billions of years ago. The finding contrasts with another theory that this era was mainly cold and icy. The result has implications for the idea that ...

Gravity feels reliable—stable and consistent enough to count on. But reality is far stranger than our intuition. In truth, the strength of gravity varies over Earth's surface. And it is weakest ...