Planet - Wikipedia
A planet is a large, rounded astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. [1] .
Planet | Definition, Characteristics, & Facts | Britannica
3 天之前 · 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 …
What is a Planet? - Definition, Facts, Our Solar System - BYJU'S
A planet is a large celestial body that revolves around the sun in fixed orbits. Planets do not have any light of their own but reflect the light of the sun. Planets also do not twinkle like stars …
What Is a Planet? | NASA Space Place – NASA Science for Kids
2025年1月14日 · What Is a Planet? The Short Answer: A planet must do three things: it must orbit a star, it must be big enough to have enough gravity to force a spherical shape, and it must be …
What is a Planet? - National Geographic Kids
By 1930, nine planets had been discovered: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. But what exactly is a planet? It seems like an easy question.
Definition of planet - Wikipedia
This definition, which applies only to the Solar System (though exoplanets had been addressed in 2003), states that a planet is a body that orbits the Sun, is massive enough for its own gravity …
Planet - National Geographic Society
2024年5月21日 · A planet is a large object that orbits a star. To be a planet , an object must be massive enough for gravity to have squeezed it into a spherical , or round, shape,. It must also …
What is a Planet? | Planets – NASA Solar System Exploration
A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly …
What is a Planet? - NASA Science
2015年6月29日 · What is a planet? The question has been pondered by many since the early Greeks came up with the word "planets." Since then the number of "planets" in our solar …
What is a Planet? - ssd.jpl.nasa.gov
Using this new definition, there are eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. A new category of object called “dwarf planet” …
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