What causes gravity?

We think it may be caused by a particle called a graviton

Gravity is the ultimate force of attraction throughout the universe. Everything with mass has gravity, including stars, planets and even people. The pull of an object’s gravity gets stronger as you get closer, and its strength is proportional to the object’s mass. Something as big as Earth has enough gravity to keep us pulled down to its surface, and the Sun has enough gravity to keep Earth orbiting around it. The mathematics of gravity were first described by Isaac Newton in the 17th century, while Albert Einstein, about 100 years ago, showed how gravitation could be better understood as a warping of space and time.

Dr Robert Hurt,