Mathematician Grigori Perelman solved the Poincaré conjecture, and then rejected the $1 million prize that came with it.

Veteran astronaut Michael Fincke's sudden medical emergency aboard the ISS is a stark reminder that, as NASA pushes toward long-term lunar missions, astronaut health remains one of spaceflight's biggest unknowns.

NASA's SPHEREx space telescope detected organic molecules coming off comet 3I/ATLAS as the interstellar visitor made its closest approach to Earth in December.