Mercury is the innermost and smallest of the eight major planets in our Solar System, orbiting closest to the Sun. Though only slightly larger than Earth’s Moon, Mercury endures some of the most ...

Mercury, typically classified as the Solar System’s innermost planet, is displaying features more commonly associated with comets. On 3, Steven Bellavia captured an image from Surry, Virginia, ...

Discover which planet is the fastest in the solar system. Learn why Mercury moves at 47 km/s, has the shortest year, and ...

While Mercury is the innermost planet in the Solar System, on average it spends more time closer to Earth than Venus does.

(CNN) — The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have ...

“One explanation is the presence of an unseen planet, probably smaller than the Earth and probably bigger than Mercury, orbiting in the deep outer solar system,” said lead author Amir Siraj, an ...