The chapter clearly states that the Sun, eight planets, their moons, and many smaller objects including asteroids and comets, together form the Solar System. Pluto is mentioned as a dwarf planet that revolves around the Sun and is part of our Solar System. However, Sirius is a star in the constellation Canis Major—the brightest star in the night sky—and is not part of our Solar System. The chapter mentions that the star nearest to us after the Sun is Proxima Centauri, not Sirius.