Planetary history refers to the study of the formation and development of planets over time. It includes the processes that shaped their surfaces, atmospheres, and internal structures. Scientists use data from astronomy, geology, and planetary science to understand how planets like Earth, Mars, and Venus evolved from their initial formation in the solar system. Key events in planetary history include the accretion of dust and gas into solid bodies, volcanic activity, and impacts from asteroids and comets. These events have influenced the conditions necessary for life and the presence of water on some planets, making the study of planetary history essential for understanding our place in the universe.