The Extragalactic Atlas
The Extragalactic Atlas
The word “extragalactic” means everything outside the Milky Way, our home Galaxy. Extragalactic space consists mainly of galaxies, the building blocks of the Universe. Within the observable Universe (that part of the Universe visible to us), astronomers estimate there to be 40 billion to 100 billion of them. Imagine, 40 billion galaxies with billions of stars each. If even a tiny fraction of those stars are host to planets, there would be trillions and trillions of planets in the Universe.
The Digital Universe allows us to view these galaxies in three dimensions, revealing the weblike distribution of galaxies in our Universe. In the Milky Way Atlas we adopted the notion of a solar neighborhood. In the Extragalactic Atlas we expand on that idea and discuss our Galactic neighborhood. Beyond the neighborhood, you may wonder whether we are located in an action-packed region of the Universe or on the outskirts looking in. You may even contemplate some age-old questions: How big is the Universe? Where are we in the Universe? Is there other life in the Universe? These and other questions will be addressed in this chapter. Some will be answered, while others lie beyond current scientific knowledge.
We will start this chapter with a review of the objects found in extragalactic space and briefly discuss the origin and structure of the Universe. We will then turn to a series of tutorials in “Extragalactic Atlas Tutorial,” where we discuss the issues specific to the Atlas. Finally, we present an overview of each data set in “Extragalactic Data Groups.”
Subsections
- Extragalactic Atlas Overview
- Extragalactic Atlas Tutorial
- Extragalactic Data Groups
- Optimizing the Extragalactic Atlas
© 2002-2005 American Museum of Natural History
Last Modified: 2007-12-19 by Brian Abbott