Gravity also works on a much larger scale, with planets, stars, galaxies, and the universe in general. The gravitational pull of planets is what causes asteroids and meteors to crash into their surfaces. Gravity is also responsible for planets orbiting their respective stars, and for moons orbiting their respective planets.
Different planets have different gravitational strengths, depending on their mass. Larger, or more massive, planets, like Jupiter or Saturn, have gravitational pulls that are much stronger than the Earth’s, while smaller, or less massive planets like Mercury or Mars, have gravitational pulls that are much weaker than the Earth’s.
- It’s worth noting that the visual size of a planet isn’t what gravity is based on – the force is determined by the mass, meaning what makes up the planet. For instance, Saturn is a gas planet with much less mass for its size, while the Earth is a solid planet, with much more mass for its size. Despite this, Saturn is still much more massive than the Earth, and its size makes up for it being gaseous.
- A great example of mass versus size is comparing Earth and Uranus. Uranus is close to five times the size of Earth (radius), but it still has a weaker gravitational force than the smaller planet. Uranus is a gas planet, while the Earth is a terrestrial planet, meaning the Earth has more mass than Uranus, leading it to have a stronger force of gravity.