Understanding Light Years

The video from FreeSchool explains the concept of a light year, which is the distance light travels in one Earth year. Light travels at an incredible speed of about 186,000 miles or 300,000 kilometers per second. Despite the vast distance of 98 million miles from the sun to Earth, light covers it in just over 8 minutes. A light year equates to approximately 5.8 trillion miles or 9.5 trillion kilometers. This unit of measurement is useful for discussing the immense distances in space, such as the distance to the nearest stars in the Alpha Centauri system, which are over 4 light years away.

How is a light year defined?

• The speed of light in a vacuum.

• The distance light travels in one Earth year.

• The time it takes for light to travel from the sun to Earth.

• The distance between the Earth and the sun.

What is the approximate speed of light in kilometers per second?

• 300,000 kilometers per second

• 150,000 kilometers per second

• 98,000 kilometers per second

• 186,000 kilometers per second

How long does it take for light from the sun to reach Earth?

• 8 minutes and 20 seconds

• 10 minutes and 30 seconds

• 12 minutes and 40 seconds

• 5 minutes and 20 seconds

Approximately how many trillion miles is one light year?

• 3.5 trillion miles

• 9.5 trillion miles

• 5.8 trillion miles

• 7.2 trillion miles

How far away are the stars in the Alpha Centauri system from Earth?

• 6 light years

• 8 light years

• 2 light years

• 4 light years