If you go to the country, far from city lights, you can see about 3,000 stars on a clearnight. If your eyes were bigger, you could see many more stars. With a pair of binoculars, an optical device that effectively enlarges the pupil of your eye by about 30
times, the number of stars you can see increases to the tens of thousands. With a
medium-sized telescope with a light-collecting mirror 30 centimeters in diameter,
you can see hundreds of thousands of stars. With a large observatory telescope,
millions of stars become visible.
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