1. Star Messages Module A Chapter 2 Grade 6 Science

2. Visible Spectrum Visible spectrum is the small range of wavelengths that humans can see. **White light is made up of the many different wavelengths of the visible spectrum mixed together.

3. Frequency The number of waves passing a point at a given time. ***knowing the frequency can help you determine the element.

4. Electromagnetic Spectrum

5. Spectrometer Instrument that separates the different colors in a beam of light. Starlight appears white- different colors blend together When light passes through a spectrometer, you can see distinct lines of spectrum

6. Telescope An instrument that allows scientists to gather light from distant objects. Refracting Telescope Advantages: Easier to maintain Gives a clearer picture Disadvantages: More expensive Lenses are harder to make Reflecting Telescope Advantages: Cheaper Mirrors are easier to make Disadvantages: Mirrors need to be cleaned and coated

7. Refraction: The bending of light Light bends as it changes speed while passing from one material to another Reflection: The bouncing of light off of a surface

8. Lenses refract, bend light as it passes through Concave lens Middle thinner than edges, light spreads out as it passes through lens

9. Lenses refract, bend light as it passes through Convex Middle is thicker than edges, light comes together in a focal point. Refraction telescope uses a pair of convex lenses

10. Mirrors reflect, bounce light Concave Mirror Light bounces toward center to focal point Convex Mirror Light bounces outward and spreads apart

11. Quasars Quasars are clusters of extremely bright stars, billions of light years from earth that give off a lot of energy in the form of x-rays.

12. How do scientists study the universe? Scientist get clues from x-rays from distant parts of the universe about quasars; gamma ray images five clues about what distant stars are made of, infrared waves give clues about new stars.