The Basic types of galaxy are spiral, elliptical, and irregular. 5. Describe the basic types of galaxies. 1.Spiral galaxy: _____________ 2.Elliptical galaxy: ___________ 3.Irregular galaxy: ___________
Elliptical galaxies are spherical to elongated, football-like shapes
Spiral galaxies are the most numerous among the larger galaxies. The nearest spiral galaxy to us is the Andromeda Galaxy, which is 2,300,000 light-years away from us. Our Milky Way Galaxy is a spiral galaxy.
6. How do scientists observe the Galaxies in the Universe? __________________________________________
Our solar system is in a galaxy called the Milky Way. Scientists estimate that there are more than 100 billion galaxies scattered throughout the visible universe. Astronomers have photographed millions of them through telescopes.
The Milky Way has a diameter of about 100,000 light-years. The solar system lies about 25,000 light-years from the center of the galaxy. There are about 100 billion stars in the Milky Way.
The speed of light in vacuum, 299,792,458 meters per second and is about 186,282 miles per second. http://www.youtube.com/watch?v=Rj1sDWjvgjM