# Kepler's Third Law: Mass of Sun and Newton's Law

• The legend
In summary, Kepler's Third Law, also known as the Law of Harmonies, states that the square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit. It is significant in astronomy because it allows for the calculation of the mass of celestial bodies and helped pave the way for our understanding of gravity. It is still used in modern scientific research to study exoplanets.
The legend
I read somewhere that the mass of the sun can be determined using Keplers third law. How is this possible without indulging Newton's law(gravitation) in ?

Astronomy news on Phys.org
It can be determined using kepler's third law, but not with kepler's third law alone. Only the ratios of different periods and semi-major axes can be compared with kepler's third law.

That's what i felt.. thanks for the reply

## 1. What is Kepler's Third Law?

Kepler's Third Law, also known as the Law of Harmonies, states that the square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.

## 2. How is the mass of the Sun related to Kepler's Third Law?

According to Kepler's Third Law, the mass of the Sun affects the orbital period of planets around it. The greater the mass of the Sun, the longer the orbital period of the planets.

## 3. How does Newton's Law relate to Kepler's Third Law?

Newton's Law of Universal Gravitation explains the force of gravity between two objects, which is a key factor in Kepler's Third Law. The gravitational force between the Sun and planets determines their orbital periods and shapes of their orbits.

## 4. What is the significance of Kepler's Third Law in astronomy?

Kepler's Third Law is significant because it allows astronomers to calculate the mass of celestial bodies, such as planets and stars, based on their orbital characteristics. It also helped pave the way for Newton's Law of Universal Gravitation and our understanding of gravity.

## 5. How is Kepler's Third Law used in modern scientific research?

Kepler's Third Law is still used in modern scientific research to study the properties of exoplanets, or planets outside of our solar system. By measuring the orbital period and semi-major axis of exoplanets, scientists can estimate their masses and learn more about their compositions and environments.

Replies
1
Views
1K
Replies
18
Views
2K
Replies
6
Views
1K
Replies
3
Views
1K
Replies
1
Views
2K
Replies
1
Views
1K
Replies
2
Views
932
Replies
3
Views
1K
Replies
15
Views
1K
Replies
10
Views
5K