Astronomy Fundamentals

Matter and Energy

What is the speed of light?

Light travels through a vacuum at 299,792,458 meters per second, or 186,282.4 miles per second, or 670 million miles (1.078 billion kilometers) per hour, or 5.8 trillion miles (9.2 trillion kilometers) per year! A beam of light can go from New York to Tokyo in less than one-tenth of a second, and from Earth to the Moon in less than 1.3 seconds.


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