Science Starter 2/16/17 Write in your agenda. Answer the following on your Thursday bellwork slot. A diagram of Earth revolving around the sun is shown. Spring is occurring in the Northern Hemisphere when Earth is at which position? A. 1 B. 2 C. 3 D. 4 What steps did you take to solve this?

Components of the Universe

SPI 6.1 Use data to draw conclusions about the major components of the universe.

Success Criteria I CAN identify the 3 types of galaxies.

Galaxies Galaxies are large groupings of stars in space. Galaxies come in a variety of sizes and shapes.

Galaxies The largest galaxies contain more than a trillion stars. Galaxies began to be classified by their shapes in the 1920s by Edwin Hubble.

3 Types of Galaxies Spiral Elliptical Irregular

Types of Galaxies: Spiral Spiral Galaxies - a huge bulge at the center and very distinctive spiral arms. The center of the galaxy appears yellow because it contains cooler stars. Hot blue stars in the spiral arms make the arms in spiral galaxies appear blue.

Types of Galaxies: Elliptical Elliptical galaxies have very bright centers and very little dust or gas. These galaxies are cucumber shaped with the round end facing us.

Types of Galaxies: Elliptical Because there is so little gas, there are no new stars forming, and therefore elliptical galaxies contain only old stars.

Types of Galaxies: Irregular When Hubble first classified galaxies, he had a group of leftovers. He named them “irregulars.” Irregular galaxies are galaxies that do not fit into any other class.

Types of Galaxies: Irregular As their name suggests, their shape is irregular. The gravity of large spiral galaxies may be distorting the shape of these galaxies.

Learn about the Galaxy

Contents of Galaxies Galaxies are composed of billions and billions of stars. But besides the stars and the planetary systems many of them probably have, there are larger features within galaxies that are made up of stars or the material of stars. open clusters quasars nebulas globular clusters

Nebulas In space, nebulas are giant clouds of gas and dust. Some types of nebulas glow by themselves, while others absorb light and hide stars. Some nebulas are regions where new stars form (like the Eagle nebula above). Spiral galaxies generally contain nebulas, but elliptical galaxies do not.

Quasars Among the most distant objects are quasars, which look like tiny points of light. Quasars are among the most powerful energy sources in the universe. The quasar at the right is as powerful as 10 billion suns. Some scientists think they may be young galaxies with massive black holes at their centers.

Pictures of the Hubble Telescope

Feeling Successful On a note card… Identify the three types of galaxies and give a brief description or picture of each. Place in the folder that describes how YOU feel today about the lesson and your response.