By Length
Full (4-12 min)
Short (1-4 min)
By Date
2024 | 2023 | 2022 | 2021
2020 | 2019 | 2018 | 2017
2016 | 2015 | 2014 | 2013
2012 | 2011 | 2010 | 2009
2008 | 2007 | 2006
By Category
Solar System
Stars
White Dwarfs
Supernovas
Neutron Stars
Black Holes
Milky Way Galaxy
Normal Galaxies
Quasars
Groups of Galaxies
Cosmology/Deep Field
Miscellaneous
HTE
STOP
Space Scoop for Kids!
Chandra Sketches
Light
AstrOlympics
Quick Look
Visual Descriptions
Subscribe
How To
RSS Reader
Audio-only format podcast
Web Shortcuts
Chandra Blog
RSS Feed
Chronicle
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

View/Listen
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 knows...it 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