The word planet comes from the Greek πλανήται (planḗtai) 'wanderers'. In antiquity, this word referred to the Sun, Moon, and five points of light visible to the naked eye that moved across …

Dec 29, 2025 · Planet, broadly, any relatively large natural body that revolves in an orbit around the Sun or around some other star and that is not radiating energy from internal nuclear fusion …

May 28, 2025 · A more modern definition can be found in the Merriam-Webster dictionary which defines a planet as "any of the large bodies that revolve around the Sun in the solar system."

Come discover our planetary neighborhood—as if from interstellar space, moving in toward our Sun. This “outside-in” perspective is how we may someday explore other solar systems. What …

May 21, 2024 · Discovered in 1930, it was long considered the ninth planet in our solar system. But in 2006, the International Astronomical Union revised its definition of a planet. Under the …

The English word planet comes from the Greek planēs. Unlike the ancient Greeks, we now know that the planets "wander" across the sky because they are revolving around the sun.

Jan 3, 2026 · Solar system, assemblage consisting of the Sun and those bodies orbiting it: 8 planets with more than 400 known planetary satellites; many asteroids, some with their own …

Oct 18, 2023 · According to a definition issued by the International Astronomical Union (IAU) in 2006, a planet is a celestial body that: orbits the Sun; possesses sufficient mass to assume a …

Mar 12, 2025 · What is a Planet? The word goes back to the ancient Greek word planēt, and it means "wanderer." A more modern definition can be found in the Merriam-Webster dictionary …

Jan 3, 2026 · This process would have continued through the formation of several concentric rings, each of which then would have coalesced to form a planet. Similarly, a planet’s moons …