The formation of Venus is thought to have occurred through processes similar to those that formed other terrestrial planets. The leading theory suggests that Venus formed from the solar nebula, the cloud of gas and dust left over from the Sun's formation, through a process called accretion. Over millions of years, dust and particles in the nebula clumped together to form larger bodies, eventually creating a planet-sized object. Venus's proximity to the Sun and the conditions in the early solar system likely influenced its composition and subsequent atmospheric development. Theories also propose that Venus may have had a more Earth-like climate in its early history before experiencing a runaway greenhouse effect.