Lesson 5 Splash galaxy Milky Way spectrum expansion redshift big bang Look and Wonder One way to group objects is to sort them by shape. You can apply the same method to galaxies, such as the Whirlpool Galaxy (M51). How do the shapes of different galaxies compare? Possible answers: They differ in the number of stars, and they differ in their shapes and sizes. background radiation Lesson 5 Splash

Lesson 5 Vocab a More than 100 billion. How many galaxies are in the universe? More than 100 billion. More than 100 billion. Lesson 5 Vocab a

Types of Galaxies There are 3 types of galaxies: 1. Spiral

2. Elliptical

3. Irregular

Lesson 5 Vocab b How many stars are in our galaxy? More than 100 billion. More than 100 billion. Lesson 5 Vocab b

If 2 galaxies are approaching, then the wavelength becomes shorter and the colour of light is blue. If 2 galaxies are moving away, then the wavelength becomes longer and the colour of light is red. If 2 galaxies are approaching, then the wavelength becomes shorter and the colour is blue. Lesson 5 Vocab c

Andromeda galaxy is moving toward Milky Way galaxy Andromeda galaxy is moving toward Milky Way galaxy. The collision will happen in 4 billion years.

Lesson 5 Vocab e It expands. What is happening to the universe after the Big Bang? It expands. It expands. Lesson 5 Vocab e

Lesson 5 Vocab f