ch3

Newton’s universal law of gravitation states that all bodies in the universe – large and small – exert a pull on every other body. The extent of their pull is proportional to their mass.

Stars, which are huge, have a gravitational pull strong enough to bring planets into orbit.

Weight of the Earth, it’s about 5.9725 billion trillion metric tons, if you’re wondering.

Earth is not spherical. The force of the Earth’s spin causes it to flatten slightly at the poles and bulge at the equator. So, to be precise, the Earth is an oblate spheroid rather than a true sphere.