Q&A: General Astronomy and Space Science
Q:
What are light years and why are they used in astronomy?
A:
In astronomy, distances are measured in units of light years,
where one light year is the distance that light travels in a
year—10 trillion kilometers. For historical reasons having
to do with measuring distances to nearby stars, professional
astronomers use the unit of parsecs, with one parsec being equal
to 3.26 light years.
For a complete discussion on light years and cosmic distance
please see http://chandra.harvard.edu/photo/cosmic_distance.html
An overview of the Chandra mission and goals, Chandra's namesake, top 10 facts.
Classroom activities, printable materials, interactive games & more.
Overview of X-ray Astronomy and X-ray sources: black holes to galaxy clusters.
All Chandra images released to the public listed by date & by category
Current Chandra press releases, status reports, interviews & biographies.
A collection of multimedia, illustrations & animations, a glossary, FAQ & more.
A collection of illustrations, animations and video.
Chandra discoveries in an audio/video format.
