The gravitational pull of the planets is visualized

Gravity is one of the fundamental forces in the universe without which life as we know it was impossible. 

The gravity of the sun holds all the planets in orbit in our solar system. However, every planet, natural satellite, and asteroid have their own gravitational pull determined by their size, mass, and density.

Dr. James O'Donoghue, a Planetary Astronomer at Japan Aerospace Exploration Agency, built an animation that clarifies this concept by visualizing the time it takes a ball to drop from one kilometer to the surface of various planets and the Earth's moon, assuming no air impedance.

Interestingly, some giant planets have a pull comparable to smaller ones at the surface; for instance, Uranus pulls the ball down slower than Earth. That is happening because the low average density of Uranus puts the surface far away from the majority of the mass (hence the more minor pull). Likewise, Mars has a mass almost twice Mercury, but you can observe the surface gravity is the equivalent. It suggests that Mercury is much denser than Mars.

Jupiter has the strongest gravitational field among all planets of our Solar System. The animation created by Reddit user AristonD clearly illustrates how Jupiter protects our planet from asteroids. 

I think that if it were not for Jupiter, the probability of asteroids like the one that fell on our planet 66 million years ago and wiped out the dinosaurs would be much higher.