Mass

Kepler's Laws: Find the Mass of the Sun

Many years ago, a mathematician named Johannes Kepler created a set of rules explaining planets' movement in our Solar System.

Read more


The picture shows a cartoon portrait of Johannes Kepler in front of an artist's impression of the Solar System.


What is Gravity?

Read more


Planet Earth in space. Three children are standing on the planet. Arrows show the pull of gravity from where they are on the surface into the centre of the Earth.


The 'Space Weight' Calculator

Ever wondered how heavy or light you would feel on another planet in our Solar System?

Read more


Cartoon of planets on a weighing balance in space. Jupiter is on the left side, weighing the balance is down. Earth, Mars, and Mercury are piled on top of each other on the other end of the balance.


Centre of Mass

Earth and Moon taken by
the Galileo Spacecraft
Credit: NASA

The mass of an object tells us the amount of ‘stuff’ or matter it is made of. An object’s mass remains the same wherever the object is. 

Mass and Weight

Weighing the Earth?

The mass of an object tells us the amount of ‘stuff’ or matter it is made of. An object’s mass remains the same wherever the object is. Mass is measured in kilograms (kg). Or grams for small objects, and tonnes for larger objects.