This document provides information about the planets in our solar system as well as asteroids, comets, and other celestial bodies. It details facts about each planet such as composition, size, atmospheric conditions, moons, and spacecraft missions. Key points include: the terrestrial planets like Earth are rocky, while the gas giants like Jupiter and Saturn have thick atmospheres composed primarily of hydrogen and helium; Venus' dense carbon dioxide atmosphere creates intense heat; Mars once had water and the potential for life; and asteroids and comets originate from the asteroid belt between Mars and Jupiter and the Kuiper Belt beyond Neptune's orbit. Spacecraft missions have revealed details of planets, moons, rings and other features of our solar system.