Where is our location in the Milky Way

Where is our location in the Milky Way Galaxy?

What is a galaxy? • A galaxy is a large grouping of stars, gas, and dust in space that are held together by gravity. • The largest galaxies contain more than a trillion stars. Smaller galaxies may have only a few million. • Scientists estimate the number of stars from the size and brightness of the galaxy.

Spiral Main Types of Galaxies Irregular Elliptical

Properties of Spiral Galaxies • Shaped like flattened disks with one or more spiral arms. • Our galaxy, Milky Way, is a spiral galaxy. • Our solar system is located in one of the spiral arms.

Properties of Elliptical Galaxies • About 1/3 of all galaxies. • Simply massive blobs of stars. • Round or elliptical in shape. • Contain very little gas or dust. • Because of little gas, no new stars are forming. • The largest and smallest galaxies are elliptical galaxies.

Properties of Irregular Galaxies • Do not fit into any other category. • Chaotic mix of stars, gas and dust • Usually found near large spiral galaxies who may be distorting their shape.

Contents of Galaxies are made of stars, planetary systems, gas clouds, and star clusters. Nebulas are giant clouds of gas and dust where Nebula are found stars may be in spiral galaxies but not elliptical forming. galaxies.

Galaxy Quiz

Galaxy Quiz

Galaxy Quiz

What is the name of our galaxy? +

Describe the Milky Way Galaxy

Describe the Milky Way Galaxy • • Flattened Disk Bulge in Middle Looks like Fried Egg Not solid from edge to edge Huge 1000 -3000 Light Years Thick 100, 000 Light Years across (Diameter)

Where is our solar system in our galaxy? • Think Pair Share Activity • Discovery-Where are we in the Galaxy?

X Marks the Spot • 1. Where does the Sun lie in the Milky Way Galaxy? • The Sun lies on the Orion or local spiral arm. • 2. About how far from the center of the galaxy is Earth? • Around 27, 000 light years • 3. About how wide is the Milky Way Galaxy? • Roughly 100, 000 light years across

X Marks the Spot • 4. How wide is the nuclear bulge of the galaxy? • About 30, 000 light years • 5. How do you think the Perseus and Sagittarius arms got their names? • Constellations that pass through the night sky • 6. Why is it impossible for us to see into the very center of our galaxy? • As you look into the nuclear bulge, there is too many stars and dust that block the view.

Where is our solar system in our galaxy? • The Sun and our solar system is located in one of the outer arms (Orion’s Arm) of the galaxy. The distance from the Sun to the center of the galaxy is about 30, 000 light years. • All objects in the galaxy revolve around its center bulge. • The sun and our solar system take about 240 million years to make one trip around the center of our galaxy.