By Length
Full (4-12 min)
Short (1-4 min)
By Date
2023 | 2022 | 2021 | 2020
2019 | 2018 | 2017 | 2016
2015 | 2014 | 2013 | 2012
2011 | 2010 | 2009 | 2008 | 2007 | 2006
By Category
Solar System
White Dwarfs
Neutron Stars
Black Holes
Milky Way Galaxy
Normal Galaxies
Groups of Galaxies
Cosmology/Deep Field
Space Scoop for Kids!
Chandra Sketches
Quick Look
Visual Descriptions
How To
RSS Reader
Audio-only format podcast
Web Shortcuts
Chandra Blog
RSS Feed
Email Newsletter
News & Noteworthy
Image Use Policy
Questions & Answers
Glossary of Terms
Download Guide
Get Adobe Reader

Video Podcasts: The Incredible Two-Inch Universe

Step 4: The Realm of Galaxies

Now let's switch scales one last time, and shrink the entire continent-sized galaxy down to 2 inches:
  • Size of Sun and Stars - Individual stars are invisible, smaller than atoms, at this 2-inch scale. The bright specks in this galaxy image come from the added light of thousands of stars.
  • Location of Sun - 1/2 inch (about 1 cm) from edge of 2-inch galaxy image
  • Distance to Andromeda Galaxy, the Nearest Spiral - 5 feet (1.5 m) at this scale - hold the two galaxy images apart with your arms spread wide.
  • Distance to Farthest Galaxies Observed by Hubble Telescope - 4 miles (6.5 km). In the Hubble image of the "Ultra Deep Field" almost all the fuzzy spots of light are distant galaxies. Because light takes time to travel through space, we see the farthest of these not as they are now, but as they were 12 billion years ago.
  • Size of the Whole Universe? - No one could be infinite.
  • Light Travel Time - It would take 100,000 years for a beam of light to cross our galaxy and 2.5 million years for light to travel from the Andromeda Galaxy to us.
Return to Podcasts