The mass of the Earth is an elusive quantity that fascinates both scientists and laypeople. But how and why do you calculate their weight?
Our blue planet is large and therefore has to generate a lot of mass. Accurately determining and understanding this mass is fundamental to science because weight not only influences the gravity we feel, but also has far-reaching effects on many physical and geological processes.
The Earth has an enormous mass of almost six trillion kilograms, or in other words: 5.972 x 10^24 kilograms. This mass, as the geoscientist Dr. Christoph Förste from Helmholtz Center Potsdam explains, the determination of the earth’s mass is based on Isaac Newton’s law of gravity. In the 17th century, Newton realized that all masses attract each other. The strength of this attraction depends on the mass of the objects and the distance between them. The Earth’s mass can be calculated using the law of gravity and precise measurements of the Earth’s gravitational field.
One of the crucial experiments that led to the determination of the Earth’s mass was carried out by Henry Cavendish in 1798. He used a so-called torsion balance to measure the attractive force between two small lead balls. From these measurements he was able to determine the gravitational constant G, a fundamental quantity in physics that is needed to calculate the mass of the Earth.
The mass of the Earth also plays an important role in everyday life. It affects the gravity on the earth’s surface, which keeps us on the ground. This is how life as we know it is made possible. This gravity also ensures that our atmosphere remains bound to the Earth and does not escape into space. Without the appropriate mass, the Earth would lose its gas shell and thus also the basis for life. By the way: Even without photosynthesis, life on earth would not be possible.
Earth’s mass is also important for space travel. When scientists and engineers plan spacecraft, they need to have a precise understanding of the Earth’s mass and the resulting gravitational pull in order to correctly calculate the energy required for launch and orbit.
