A spacecraft has beamed back some of the best close-up photos yet of Mercury's north pole. The European and Japanese robotic explorer swooped as close as 183 miles (295 kilometers) above Mercury's ...

"This makes these unlit craters some of the coldest places in the Solar System, despite Mercury being the closest planet to the Sun!" the ESA marveled. What's more, these craters could harbor ...

The probe's Mercury Laser Altimeter revealed bright material inside deep craters at the north pole with pulses of laser light. The bright patches match up cold spots mapped by a thermal model of ...