axis of rotation

orbit

phases of the moon

reflection

revolution

Earth’s tilt

Seasons

asteroids

celestial objects

comets distance

force gravitational

force

gravity

mass

planet

satellite

scale

solar system

stars

sun

telescope

constellation

galaxy

light-year

star

Milky Way Galaxy

sun

speed of light

universe

algae

bacteria

control

culture

decomposer

experiment

fungi

hypothesis

investigation

microorganism

organism

producer

protozoan

single-celled

variable

absorption

vibration

angle of incidence

angle of reflection

conduction

conductor

convection

medium

pitch

prism

radiation

reflection

reflection

refraction

sound

spectrum