Solar system objects are grouped by characteristics. We
model how scientists classify solar system objects. What’s a planet, dwarf
planet, etc.? Is Pluto a planet?
1. We, including scientists, group objects to help us understand and describe the world around us; 2. The way we, including scientists, group things may depend on the manner in which we are studying them, i.e., there may be more than one “correct” answer; and 3. Objects in the Solar System (planets, dwarf planets, asteroids, comets, moons) can be grouped by their properties: rocky surfaces, gaseous atmospheres, orbit around the Sun or a planet, where they are in the Solar System, etc.
Larry Lebofsky (Senior Education Specialist: Tucson, AZ)