Early in the 20th century, our Galaxy was estimated to be:
A)about 100,000 ly in diameter.
B)about 35,000 ly (10 kpc)in diameter.
C)about 10 million ly in diameter.
D)not much larger than our solar system.
E)about 2.5 million ly in diameter.

Question

Quizplus · Accepted Answer

Early in the 20th century, using the method of star counts, the size of our Galaxy was estimated to be about 35,000 ly (10 kpc) in diameter. The most accurate estimate of our galaxy's size puts it at about 100,000 light-years in diameter, which is roughly 35,000 light-years across.

Early in the 20th Century, Our Galaxy Was Estimated to Be