1. SPACE SYSTEMS UNIT
Chapters 26 & 30

2. 26.1 Viewing the Universe The Value of Astronomy
Astronomy: the scientific study of the universe
By observing the universe astronomers have:
Made exciting discoveries, such as new planets, stars, black holes, and nebulas
Been able to learn more about the origin of Earth and the processes involved in the formation of our solar system
Funded by federal agencies (NSF & NASA) as well as private foundations and industries

3. LT 1: I can describe characteristics of the universe in terms of time, distance, and organization.
Cosmology: the study of the origin, properties, processes, and evolution of the universe.
Universe began about 14 Billion years ago in one giant explosion, The Big Bang
Universe is expanding and is very large and objects within it are very far apart.

4. Organization of the Universe
Earth is in a solar system
The Solar System is in a galaxy (Milky Way Galaxy)
Galaxy: a collection of stars, dust, and gas bound together by gravity
Beyond The Milky Way are billions of other galaxies

5. Measuring Distances in the Universe
Astronomical unit (AU): approximates the average distance between Earth and the sun
About 150 million km
Light-year: distance between Earth and the sun that light travels in one year
Speed of light = 300,000 km/s
9.46 x 1012 km
Closest star to Earth (aside from the Sun) is 4.22 light-years away
Follow Notes with Skill Builder Activity:
Distances in astronomy are difficult for students to comprehend because the distances are so huge. Have students calculate how far (in km) light travels in one year based on the speed of light.
Tell them the star Sirius is located 84,321 trillion km from Earth. Have them calculate this distance in light-years.
Colors of Light Activity:
Shine a flashlight beam onto a white sheet of paper. Put a prism into the path of the beam of light. Turn the prism slightly until the spectrum appears on the paper. Ask students to describe what they see. Ask them: Which color light seems to bend the most and which color bends the least? (Students should see the colors of the rainbow. The prism bends violet the most and red the least.)

6. LT 2: I can identify the visible and nonvisible parts of the electromagnetic spectrum.
Observing Space
Electromagnetic Spectrum: all of the frequencies or wavelengths of electromagnetic radiation (EMR)
Humans only see Visible EMR
Light travels at the same speed, but have different wavelengths which produces the different colors
Invisible EMR have shorter wavelengths than Violet or longer wavelengths than Red
Discovered by Sir Frederick William Herschel in 1800 with a thermometer
Before Notes:
Pair/Share Activity
Group students into pairs and have them read silently about the electromagnetic spectrum. Then, have one student summarize what types of radiation make up the visible and invisible parts of the electromagnetic spectrum and how astronomers use these forms of energy. Direct the other student to listen to the retelling and point out any inaccuracies or ideas that were left out. Allow students to refer to the text as needed.
After Notes:
Splitting Light Activity
Explain that astronomers use an instrument called a spectrograph to analyze the light from stars. Spectrographs use prisms or diffraction gratings to break up the light. Students can see the spectrum directly through a diffraction grating cut into 3 cm squares. Set up a table lamp with the shade removed. Distribute diffraction gratings to students. Darken the room and turn on the lamp. Direct students to look at the light source through the diffraction grating. Tell them to handle the grating by the edges, as oil from their fingers will clog the openings. Have students use crayons or colored pencils to draw the spectra they see.
Student Practice:
Exit Slip: Students need to label the Electromagnetic Spectrum

7. LT 3: I can compare refracting and reflecting telescopes.
Telescope: an instrument that collects EMR from the sky and concentrates it for better observation.
Reflecting Telescopes
Uses mirrors to gather and focus light
Light is reflected off of one lens onto a 2nd mirror which then reflects the light to the eyepiece
Mirrors can be very large without affecting the quality of the image
Refracting Telescopes
Use lenses to bend light (refraction)
Objective lens gathers light
Eyepiece lens magnifies the light
Lens focuses different wavelengths of light at different distances which limits the size of the objective lens.

8. Light Telescopes Nonvisible EMR Telescopes
LT 4: I can explain how telescopes for nonvisible electromagnetic radiation differ from light telescopes.
Nonvisible EMR Telescopes
Each type of EMR must have its own telescope
Affected by Earth’s atmosphere
Most of these telescopes are in space
Hubble Space Telescope
Chandra X-ray Observatory
Spitzer Space Telescope (infrared telescope)
Light Telescopes
Reflecting and Refracting Telescopes
Largest Reflecting Telescopes are in HI

9. Other Spacecraft Voyager 1 & 2 Galileo Cassini-Huygens
Launched in 1977
Investigated Jupiter, Saturn, Uranus, and Neptune
Galileo
Orbited Jupiter and its moons from 1995 – 2003
Cassini-Huygens
Launched in 1997 and began orbiting Saturn in 2004
Spirit & Opportunity
Explore Mars beginning in 2004
Confirmed water had once been on Mars
Curiosity
Most recent rover sent to Mars
Started exploring the surface in Summer 2012