The force that attracts objects towards the Earth is known as gravity. Gravity is a fundamental force of nature that pulls objects with mass towards one another. On Earth, this force gives weight to physical objects and is responsible for keeping planets in orbit around stars, including the Earth around the Sun. Gravity is proportional to the mass of the objects involved and the distance between them; larger masses exert a greater gravitational pull. Isaac Newton first formulated the laws of gravity in the 17th century, and later, Albert Einstein expanded our understanding through his theory of general relativity.