The celestial bodies in space, like the planets and satellites, move in paths that obey the laws of motion. In this article, let’s study the motion of the Celestial Bodies and the law which governed them.
| Table of Contents |
Celestial Body
Celestial bodies or heavenly bodies are objects in space such as the sun, moon, planets, and stars. They form a part of the vast universe we live in and are usually very far from us. The glorious night sky is dotted with such objects, and when we observe them using a telescope, they reveal fascinating worlds of their own.
Motion of the Celestial Body
Paths of the celestial bodies are usually elliptical or parabolic. The planets move in elliptical orbits around the sun, whereas satellites move in elliptical orbits around the planets. The sun and the solar system itself move in an elliptical orbit around the centre of our galaxy – The Milky Way!.
Celestial Mechanics
The branch of astronomy that deals with the study of the motion of objects in space are known as celestial mechanics. These heavenly bodies move in such a way due to the attractive force of gravity. The elliptical orbit is kind of an elongated circle. Instead of having a single centre like a circle, ellipses have two centres called foci (singular=focus).
For planets in space, the centre of the sun is always at one of the focus as shown in the figure above. The larger the distance between the two foci, the more elongated the ellipse is. The amount of the elongation of the orbit is given by the eccentricity of the orbit. Most planets have a very small eccentricity. The Earth’s orbit has such a low eccentricity that both the foci lie within the sun itself! So you can say that the earth’s orbit is almost circular.
Kepler’s Laws of “Planetary Motion” in Space
Motion in elliptical orbits is governed by three laws known as Kepler’s Laws of planetary motion. These laws tell us how fast a planet goes at any point in the orbit and the time a planet takes to orbit the sun. The moon also follows an elliptical orbit around the earth following Kepler’s Laws.
Stay tuned with BYJU’S application for more such interesting articles. Also, register to “BYJU’S – The Learning App” for interactive and engaging science videos.
Frequently Asked Questions – FAQs
State Kepler’s first law of planetary motion.
State Kepler’s second law of planetary motion.
What is Kepler’s law of periods?
What are the seven celestial bodies?
How do celestial bodies move in space?
Put your understanding of this concept to test by answering a few MCQs. Click ‘Start Quiz’ to begin!
Select the correct answer and click on the “Finish” button
Check your score and answers at the end of the quiz
Visit BYJU’S for all Physics related queries and study materials
Your result is as below
Comments