


Question
How many astronomical units are in a light year?
Asked by:
Justin Dopiriak
Answer
A good approximation would be:
1 lightyear = 63240 AU (astronomical units)
Just for information, 1 lightyear is equivalent to the distance travelled by light in 1 year moving in a vacuum. 1 lightyear is about 9.4607 * 10^{15} metres.
1 astronomical unit (AU) is equivalent to the average radius of the Earth's orbit. 1 AU is about 1.4960 * 10^{11} metres.
Simple arithmetic calculation yields the answer that 1 lightyear = 63240 AU to a good approximation.
Answered by:
Ryan Leong, Undergraduate, NUS, Singapore

