Planetary engineering is the theoretical practice of modifying a planet's environment to make it more habitable for humans or other life forms. This can involve altering the atmosphere, temperature, or surface conditions of a planet, such as Mars or Venus, to support life. Techniques may include introducing greenhouse gases, creating artificial magnetic fields, or even redirecting asteroids to impact a planet. The concept is often discussed in the context of terraforming, which is the process of transforming a hostile environment into one that resembles Earth. While still largely speculative, advancements in technology and our understanding of planetary systems may one day make planetary engineering a reality.