Weighing Planet Earth

For start, the earth is floating in space, so it seems that it is impossible to weigh it. Weighing the earth would not be the same method we use in weighing things on a scale. Therefore, when we speak of the earth’s weight, it means that it is the total mass of all the matters that makes up our planet.

The mass of the earth is about 6,600 trillion tons. In numerical form, it weighs 6,600,000,000,000,000,000,000 tons. See how many zero’s there is?

But how did our scientists find a way on how to measure the mass of the earth?

 To explain, it

would be better for us to know some basic principles. We know that any two objects will attract each other. In other words, this is the concept of gravity. The law of gravity states that “two objects are attracted by a force that depends on their mass and their distance apart”. This means that the bigger the object is, the greater the force that pulls them together. And when two objects are very far from each other, the force will be much smaller.

Knowing this universal concept, scientists had conducted an experiment to measure the weight of the earth which is described as follows:

1. A small object is suspended in the air by a string. The exact weight of this object is measured from its exact position.
2. Next, a
   ton of lead is brought near the suspended object. This resulted to an attraction of the ton of lead and the object and causes the object to slightly pull a very tiny bit out of its place.
3. The objects current position is then measured to the exact displacement.
4. Now, scientists are able to use math to figure out the weight of the earth. They had measured the power of the earth’s attraction on the object at air. And they also had measured the power of the ton of lead attraction towards the object suspended in the air.
5. The difference of each attraction is further computed so reveal the exact mass of the earth.

The next question is “What is this mass made off?” First, there is the crust of solid rock, then followed by a layer called the mantle. The mantle is also a solid rock which is about 1,800 miles thick. The third layer is the innermost part which is the core. The core is about 2,100 miles radius in liquid form due to the heat generated at the center of the earth.