How did scientists from before 1900’s measure the Earth’s weight and other planets/stars

Question

How did scientists from before 1900’s measure the Earth’s weight and other planets/stars

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Answer 1

The speed at which something orbits a planet or star depends on the mass of the planet or star and the radius of the orbit. The mass of the thing doing the orbiting doesnt matter.

So you can measure the relative speed of say Ganymede, and the radius of the orbit and get the mass of Jupiter from that.

You don’t need to know how much Ganymede weighs. The speed and orbit radius can be seen and measured with a telescope.