All the components of our solar system and universe function as a system. • Gravity is the force that holds our solar system and our universe together. • Our sun and our solar system is one of hundreds of billions in our galaxy and our galaxy is one of hundreds of billions in our universe. • As Technology (including telescopes, satellites, and space travel) expands so does our knowledge of our universe, but our knowledge and technology is limited.
Spickelmier, Courtney, "Our World in Space [6th grade]" (2008). Understanding by Design: Complete Collection. 63.