A planet is a large celestial body that revolves around the sun in fixed orbits.
Explanation: Because they reflect the sun's light, planets do not produce any light of their own. Because they are far closer to us than stars, planets do not twinkle like stars do. The only area in the cosmos where we know of that supports life is the earth, which is also a planet.
Similar to how the earth spins once every 24 hours, every planet revolves around its own axis. The period of revolution of a planet is the length of time it takes to rotate around the sun.
This seemingly simple question doesn't have a simple answer. Everyone knows that Earth, Mars and Jupiter are planets. But both Pluto and Ceres were once considered planets until new discoveries triggered scientific debate about how to best describe them—a vigorous debate that continues to this day. The most recent definition of a planet was adopted by the International Astronomical Union in 2006. It says a planet must do three things:
It must orbit a star (in our cosmic neighborhood, the Sun).
It must be big enough to have enough gravity to force it into a spherical shape.
It must be big enough that its gravity cleared away any other objects of a similar size near its orbit around the Sun.
Answers & Comments
Answer:
A planet is a large celestial body that revolves around the sun in fixed orbits.
Explanation: Because they reflect the sun's light, planets do not produce any light of their own. Because they are far closer to us than stars, planets do not twinkle like stars do. The only area in the cosmos where we know of that supports life is the earth, which is also a planet.
Similar to how the earth spins once every 24 hours, every planet revolves around its own axis. The period of revolution of a planet is the length of time it takes to rotate around the sun.
Answer:
This seemingly simple question doesn't have a simple answer. Everyone knows that Earth, Mars and Jupiter are planets. But both Pluto and Ceres were once considered planets until new discoveries triggered scientific debate about how to best describe them—a vigorous debate that continues to this day. The most recent definition of a planet was adopted by the International Astronomical Union in 2006. It says a planet must do three things: