Mercury, the closest planet to the sun, is only slightly larger than Earth's moon and is pockmarked with craters. The planet is visible to the unaided eye and as such as has long been known to humans.

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 ...

The 2024 astronomical calendar is packed with events; And there's more to look forward to, despite the eclipse and auroras already having passed overhead. Nicknamed the "planet parade," a planetary ...

A five-planet alignment will be visible in the night sky on Tuesday. Don't miss your lucky chance to see the stars -- or planets -- align. A five-planet alignment of Mercury, Jupiter, Venus, Uranus ...