Which planet is closest to the Sun in our solar system?

Mercury is the closest planet to the Sun in our solar system. It is the smallest of the eight planets and orbits at an average distance of about 57.91 million kilometers (approximately 36 million miles) from the Sun. Due to its proximity, Mercury experiences extreme temperature variations, with daytime temperatures soaring high enough to melt lead, while nighttime temperatures plummet dramatically. Understanding the position of Mercury in relation to the Sun helps explain its swift orbit and the conditions it experiences, including having a very thin atmosphere that cannot retain heat. This knowledge is foundational in studying planetary science and the dynamics within our solar system.