Our Place in the Universe Really just our place in our galaxy.
Ancient Astronomers The earth is the center of the universe. The universe consists of the solar system. https://en.wikipedia.org/wiki/File:Bartolomeu_Velho_1568.jpg
The Copernican Revolution The sun is the center of the universe. The universe consists of the solar system and surrounding stars. http://en.wikipedia.org/wiki/File:Geoz_wb_en.svg Creative Commons
1800’s: Herschel and Kapteyn The solar system is the center of the universe. The universe consists of the Milky Way galaxy. http://en.wikipedia.org/wiki/File:William_Herschel01.jpg http://en.wikipedia.org/wiki/File:Herschel-Galaxy.png http://en.wikipedia.org/wiki/File:Jacobus_Kapteyn.jpg Sun at center All images
Our galaxy is a disk shape with the sun at the center. Our galaxy so far… Our galaxy is a disk shape with the sun at the center. Sun
Harlow Shapley Used the distribution of and distance to globular clusters to determine the shape of the galaxy Globular clusters: gravitationally bound group of tens of thousands of very old stars Sun is off-center http://en.wikipedia.org/wiki/File:NGC_7006_%28HST%29.jpg
Our galaxy so far… Our galaxy is a disk shape, with the sun off-center, surrounded by a halo of globular clusters. Sun
Central Bulge When observed using infrared light, there is a bright area of the sky in the direction of the center of our galaxy. Infrared light can travel past the dust in the disk. Central bulges are found in most other disk-shaped galaxies. http://commons.wikimedia.org/wiki/File:Milky_Way_infrared.jpg http://hubblesite.org/gallery/album/pr2007041a/ NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration Above: Atlas Image courtesy of 2MASS/UMass/IPAC-Caltech/NASA/NSF
Our galaxy so far… Our galaxy is a disk shape, with the sun off-center, a central bulge and is surrounded by a halo of globular clusters. Sun
Spiral Arms Using radio waves (a type of EM radiation), clouds of hydrogen can be found to lie along bands or arms in our galaxy. http://en.wikipedia.org/wiki/File:Milky_Way_Arms.svg Creative Commons
http://en. wikipedia. org/wiki/File:236084main_MilkyWay-full-annotated http://en.wikipedia.org/wiki/File:236084main_MilkyWay-full-annotated.jpg
Our Place in the Universe Activity