I am composed of mainly rock. I am one of the four planets closest to the sun. I am denser than the four planets farthest from the sun. Who am I?

I am the end of the life cycle for a massive star. I occur when the star collapses and generates a high amount of energy, causing an explosion. Who am I?

I am the force that holds the materials in stars together. I am the force that causes planets to orbit the sun. I am the force that holds all celestial bodies in a galaxy together. Who am I?

I am the largest level of organization in space. Who am I?

I contain solar systems, stars, rocks, and other celestial bodies. There are billions of me in space. Who am I?

Longer wavelengths of light create a red color. Shorter wavelengths of light create a blue color. Galaxies that are moving AWAY from Earth will emit a

The theory that the universe is expanding is based on evidence that

Fill in the blank to complete the life cycle of an average sized star:

nebula, main sequence, ________________, white dwarf

CHALLENGE: What is the name of the scientist who discovered that galaxies are moving apart?

CHALLENGE: What type of scientist studies space and all of its celestial bodies?