One week ago, NASA's MESSENGER spacecraft transmitted to Earth the first high-resolution image of Mercury by a spacecraft in over 30 years, since the three Mercury flybys of Mariner 10 in 1974 and ...

Mercury is a planet that just doesn't make sense. It's incredibly small yet hosts a relatively massive core. Mercury is so strange that astronomers have not been able to explain its properties with ...

Far smaller and closer to the Sun than it should be, Mercury has long baffled astronomers because it defies much of what we know about planet formation. A new space mission arriving in 2026 might ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. An inner planet that pings around the Sun in a mere 88 days, ...

Caloris in Color – An enhanced-color view of Mercury, assembled from images taken at various wavelengths by the cameras on board the MESSENGER spacecraft. The circular, orange area near the center-top ...

It’s a world where the Sun stops in the sky at noon and spins a small circle. Where you’d celebrate your annual birthday twice every day. In places, it’s as cold as the temperature of liquid air; ...

Mercury, the speedy little planet closest to the sun, is making a special twilight appearance this month as a bright pink dot low in the sky. The show started on Feb. 8 and will continue until Feb. 21 ...

NASA's Messenger spacecraft will make history Thursday when it becomes the first probe to orbit the planet Mercury. But it also promises to help solve a host of mysteries about the solar system's ...