Download Science Lesson 24: Galaxies

Name: ____________________________________ #_______ Solar System Notes Measuring Up! Science Lesson 24: Galaxies California Content Standards: __________: Students know galaxies are clusters of billions of stars and may have different shapes. __________: Students know how to use astronomical units and light years as measures of distances between the Sun, stars, and Earth. Language of the Discipline: › A _______________ is a cluster of billions of _______________ and associated gas and dust in space that is bound by _______________. › A _______________ is a large cloud of _______________ and _______________ where _______________ are born in space. › A _______________ is a unit of length equal to about _______________ kilometers. It is the distance that _______________ can travel in one _______________. › An _______________ (AU) is the unit of _______________ equal to the average distance from the _______________ to the _______________. Guided Questions: › How is the universe currently changing? › What are galaxies made up of? Galaxy Type Description Illustration Guided Questions (cont.): › What kind of stars are often found in elliptical galaxies? › What is a light year? › List four kinds of galaxies. › How many astronomical units away are we from the Sun? › Approximately how many kilometers are in 2 light years? Apply: 1. Read the paragraph at the top of page 163. 2. Examine the illustration of a galaxy on page 163. What type of galaxy is shown in the illustration? 3. Describe characteristics of the type of galaxy shown in the illustration on page 163. 4. The galaxy shown in the illustration on page 163 is 52 light-­‐years away from the next closest galaxy. Over time, how will this distance most likely change? Why? 5. The Milky Way galaxy seen from Earth stretches like a cloud across the night sky. How come the Milky Way galaxy does not appear to be a spiral from earth? Assessment Practice: 1. The galaxies in the universe vary in age. Which type of galaxy in the universe most likely is the oldest? A a spiral galaxy 2. In the early universe, stars most likely formed from which of the following objects? A planets B an elliptical galaxy B comets C a dwarf galaxy C nebulas D an irregular galaxy D asteroids 3. Which of the following units of measurement is most appropriate for measuring between galaxies in space? A a mile 6. What is the correct way to write 38,000,000,000,000 km in Scientific Notation? A 38.0 x 1012 B a fathom B 3.8 x 1013 C a kilometer C 0.38 x 1014 D a light year D 38.0 x 10-­‐12 4. The North Star is approximately 4,085 trillion kilometers away from Earth. If 1 light year equals 9.5 trillion kilometers, how many light years away is the North Star? A 2.32 light years B 4.30 light years D an irregular galaxy C 43 light years D 430 light years 5. The closest star to the sun, Proxima Centauri, is about 38,000,000,000,000 km (38.0 x 1012 km), or about 4 light years, away. If a space probe could travel at the speed of light (about 30000,000 km/s), how long would it take to get to Proxima Centauri? A 400 years B 40 years C 4 years D 4 months 7. Which type of galaxy does Earth belong to? A a spiral galaxy B an elliptical galaxy C a dwarf galaxy